Safety Recommendation A-13-021

We are pleased that the Utah State Legislature passed H.B. 53, Meteorological Evaluation Towers, during its 2020 general session. We note that the law became effective on May 5, 2021, and requires METs to be marked; however, Safety Recommendation A 13-21 also recommends that all METs be registered.

The purpose of MET registration is to create and maintain a statewide MET directory that pilots can use during flight planning as an added layer of safety. Even with markings, METs may not be clearly evident at times of low visibility, such as at night.

We note that Utah does not plan to create a MET directory because the Federal Aviation Administration (FAA) will create a national MET database, as required by the FAA Reauthorization Act of 2018, and you believe creating a separate MET database for your state would be duplicative of the FAA’s efforts. The FAA has delayed publication of its notice of proposed rulemaking (NPRM), “Requirements to File Notice of Construction of Meteorological Evaluation Towers and Other Renewable Energy Projects,” until April 30, 2022. After that, the FAA must publish the final rule before developing the national MET database.

Although we agree that the requirements of the FAA Reauthorization Act of 2018 address the remaining action needed to complete this recommendation, we are concerned by the FAA’s continuing delays in complying with the congressional mandate. Despite the act requiring that the MET database be available by October 5, 2019, the FAA has not yet issued an NPRM or a final rule to address this issue. Accordingly, Safety Recommendation A-13-21 remains classified OPEN-- ACCEPTABLE RESPONSE to Utah, pending publication of the FAA’s final rule and the FAA’s development of a nationwide MET database, or until Utah has established the recommended statewide MET directory.

When the FAA publishes the final rule, we may revise the status of and close Safety Recommendation A-13-21.

-From Carlos M. Braceras, P.E., Executive Director, Utah Department of Transportation: Regarding your letter to Governor Spencer Cox addressing Utah House Bill 53, Meteorological Evaluation Towers, we were glad to comply with Safety Recommendation A-13-21 by implementing a state requirement to have all MET towers in Utah properly marked in compliance with FAA advisory circulars.

However, we feel it redundant to implement a state MET tower database in conjunction with the federal MET tower database.

You may be aware that in the FAA Reauthorization Bill of 2018, Section 576 'Tower Marking', the FAA Administrator is directed to develop a new national database for towers including MET towers. We believe this national database meets the safety requirements and needs for A-13-21.

The Digital Obstacle File (DOF) may be found at: https:/ /www.faa.gov/air traffic/flight info/aeronav/digital products/doff.

We are pleased that the Utah State Legislature passed H.B. 53, Meteorological Evaluation Towers, during its 2020 general session. The law became effective on May 5, 2021, and requires the marking of METs; however, Safety Recommendation A 13-21 also recommends that all METs be registered.

The purpose of MET registration is to create and maintain a statewide MET directory, which pilots can use during flight planning as an added layer of safety. Even with markings, METs may not be clearly visible at times of low visibility, such as at night. Without a registry of METs in Utah, METs remain a hazard to low-altitude aviation operations, particularly during times of low visibility. Pending your state requiring METs in Utah be registered, Safety Recommendation A-13-21 remains classified OPEN-- ACCEPTABLE RESPONSE.

Please update us at ExecutiveSecretariat@ntsb.gov on your progress toward implementing this recommendation, and do not submit both an electronic and a hard copy of the same response.

-From Carlos M. Braceras, P.E., Executive Director, Utah Department of Transportation: This letter is to convey information regarding a recommendation made by the National Transportation Safety Board (NTSB) to the State of Utah to take action to mitigate risks associated with meteorological evaluation towers (MET) and low-altitude aviation operations.

The Utah State Legislature adopted a bill, H.B. 53, Meteorological Evaluation Towers, in the 2021 General Session. Under the bill, the state incorporated recommendations made by the NTSB, including requirements for METs to be marked which includes painting alternating band of orange and white, safety sleeves, spherical markers, and a flashing light. The new law became effective on May 5, 2021. A copy of the legislation has been included for your information.

Thank you for your continued work to improve transportation safety.

-From Lisa Freeman, Executive Director of Louisiana Highway Safety Commission: Please allow this correspondence to serve as a response to the National Transportation Safety Board's recommendation A-13-21 to the Honorable John Bel Edwards requesting that the State of Louisiana pass legislation to require that meteorological evaluation towers erected in our state be marked and registered in a directory.

A review of recommendation A-13-21 indicates that this request was made during the administration of former Governor Jindal apparently due to multiple plane collisions with meteorological towers many years ago. In discussions with the NTSB, we have confirmed that this matter is to be classified as "Closed." Additionally, because this issue is not within the purview of Louisiana Highway Safety Commission responsibility, any further inquiry regarding this matter should be forwarded to the appropriate state department or jurisdiction.

We are encouraged to learn of your efforts to advocate that METs erected in your state follow the guidance for marking and lighting METs contained in the Federal Aviation Administration’s (FAA’s) Advisory Circular (AC) 70/7460-1L, “Obstruction Marking and Lighting.” We agree that a federal requirement for all METs to be marked and registered in a directory would be the most efficient solution to this problem, and we have issued recommendations similar to A-13-21 to the FAA; however, considering the FAA’s lack of action to address this issue, we encourage you to also consider legislation that would require that METs in your state be marked and registered in a directory.

Pending completion of the recommended action, Safety Recommendation A-13-21 remains classified OPEN--ACCEPTABLE RESPONSE.

We note that, due to the low winds in your state, Florida is not an ideal location for METs. We appreciate your consideration of this important safety issue; however, because you determined that METs are rarely erected in your state, Safety Recommendation A-13-21 is classified CLOSED--RECONSIDERED.

Thank you for your letter and for considering this important safety issue.

We are encouraged to learn that, during the upcoming 2020 general session, your executive branch is planning to work with the Utah State Legislature to consider legislation that would require that METs in your state be marked and registered in a directory.

We would appreciate receiving periodic updates as you progress toward this goal. In the meantime, pending completion of the recommended actions, Safety Recommendation A-13-21 remains classified OPEN-ACCEPTABLE RESPONSE.

We issued this recommendation because of our concern that METs can be erected quickly and, depending on their location, can change the airspace for low-flying operations without notice to the local aviation community. In addition, because their height is typically just under 200 feet above ground—which is the threshold that requires Federal Aviation Administration (FAA) Form 7460 as well as a marking and lighting plan—METs are often erected without markings and lighting. Because of these factors, pilots have reported difficulty seeing METs from the air, which has led to accidents.

We agree that a federal requirement for all METs to be marked and registered in a directory would be the most efficient solution to this problem, and we have issued recommendations similar to A-13-21 to the FAA; however, considering the FAA’s lack of action to address this issue, we are encouraged to learn that, during the 2020 general session, you plan to consider legislation that would require that METs in your state be marked and registered in a directory.

Safety Recommendation A-13-21 is currently classified “Closed—Unacceptable Action/No Response Received” to your state; however, if you notify us that the recommended legislation has been enacted in Tennessee, we will consider changing the recommendation status to more accurately reflect your efforts.

We appreciate your interest in improving aviation safety.

We are pleased to learn that, in 2012, Missouri enacted a law to require that any anemometer tower that is 50 feet above ground level or higher, is located outside the boundaries of any municipality, and whose appearance is not otherwise mandated by state or federal law be marked and painted. We believe this requirement is responsive to the first part of this recommendation. Regarding the second part of this recommendation, we note that you will continue to evaluate the need to require that all METs in your state be registered in a directory noting their locations; however, at this time, you believe the existing marking requirement is sufficient.

Although your efforts to require MET marking is a positive step, we believe that maintaining a directory of MET locations provides pilots with useful information and an added layer of protection in instances where environmental conditions may hamper visibility (such as at night). As the wind energy industry expands, MET deployment will also increase, and we are concerned that, without measures to record their locations, METs continue to pose a significant hazard.

Safety Recommendation A-13-21 is currently classified “Closed—Unacceptable Action/No Response Received” to your state. We note that you do not intend to enact legislation to ensure that METs in your state are registered in a directory; however, if you change your mind and notify us that this legislation has been enacted in Missouri, we will consider changing the recommendation status to more accurately reflect your efforts.

We appreciate your interest in improving aviation safety.

We are encouraged to learn that you plan to review this important safety issue and possible solutions, and we look forward to receiving periodic updates regarding your progress. Safety Recommendation A-13-21 is currently classified “Closed—Unacceptable Action/No Response Received” to your state; however, if you notify us that the recommended legislation has been enacted in Massachusetts, we will consider changing the recommendation status to more accurately reflect your efforts.

We appreciate your interest in improving aviation safety.

We note that VTrans is notified of all proposed towers during the permitting phase and, at that time, reminds the permitting entity that it must submit a completed Federal Aviation Administration (FAA) Form 7460, Notice of Proposed Construction or Alteration, to the FAA for approval and to determine if the proposed tower needs to be lighted. We also note that, although each permitting office manages its own public database for the permits issued by that office, none of these offices maintains a database with the locations of all the METs in your state. You reported that, in the last 10 years, one permit was issued for a MET, and that an FAA evaluation was also completed for that tower.

We point out that we issued this recommendation because of our concern that METs can be erected quickly and, depending on their location, change the airspace for low-flying operations without notice to the local aviation community. In addition, because their height is typically just under the 200 feet above-ground-level (AGL) threshold that requires an FAA Form 7460 and a marking and lighting plan, METs are often erected without markings and lighting. Because of these factors, pilots have reported difficulty seeing METs from the air, which has led to accidents.

Safety Recommendation A-13-21 is currently classified “Closed—Unacceptable Action/No Response Received” to your state. We note that you do not intend to enact the legislation, as recommended; however, if you change your mind and notify us that the recommended legislation has been enacted in Vermont, we will consider changing the recommendation status to more accurately reflect your efforts.

We appreciate your interest in improving aviation safety.

We note that, in 2018, the CAA pursued legislation to require that METs in your state be marked; however, the CAA suspended this effort after the Federal Aviation Administration (FAA) Reathorization Act of 2018 was signed into law.

Although we are aware that the FAA Reauthorization Act of 2018 requires the FAA to initiate rulemaking to require the marking of METs between 50 and 200 feet and to develop a database that tracks METs, we do not know the status of the FAA’s rulemaking, which is a lengthy and frequently delayed process. We point out, however, that the act does not contain specific preemptive language that would prevent states from enacting or maintaining policies of their own that are consistent with the act and FAA regulations. Considering the uncertainty of the FAA’s efforts to address this issue, we encourage the state of Connecticut to proactively enact legislation to address this important safety issue.

Safety Recommendation A-13-21 is currently classified “Closed—Unacceptable Action/No Response Received” to your state; however, if you notify us that the recommended legislation has been enacted in Connecticut, we will consider changing the recommendation status to more accurately reflect your efforts.

We appreciate your interest in improving aviation safety.

-From Gregory Slater, Acting Secretary, Maryland Department of Transportation: Thank you for your letter to Governor Larry Hogan regarding safety recommendation A-13-21. As Acting Secretary of the Maryland Department of Transportation (MOOT), I am honored to respond on behalf of the Hogan Administration.

We note that in December 2015, the Federal Aviation Administration (FAA) revised Advisory Circular (AC) 7017460-IL to include standards for working Meteorological Evaluation Tower (MET) structures. In addition, the MDOT Maryland Aviation Administration (MOOT MAA) has been strongly encouraging any proponent of MET structures to work in accordance with the FAA AC for conspicuity. At this time, a separate registry of MET structures only for Maryland is not planned. Maryland advocates for a uniform national registry of MET facilities, managed by FAA, so pilots have access to data in a single location co-located with the national Notice-to Airmen system.

Thank you for contacting the Governor. We appreciate hearing from you. If you have any additional questions or comments, please do not hesitate to contact Mr. Ricky D. Smith, Sr., MDOT MAA Executive Director. Mr. Smith will be happy to assist you.

-From Kevin J. Thibault, P.E., Secretary, Florida Department of Transportation: Thank you for your November 26, 2019, letter to Governor Desantis regarding Florida's response to A-13-21, enactment of meteorological tower regulations. The Governor asked the Florida Department of Transportation (FOOT) to respond on his behalf. At the time of the Department's original investigation in 2013, Florida had only one (1) meteorological tower located in Florida's Panhandle. FOOT reached out to the meteorological tower community and discovered Florida is not an ideal location for wind turbines due to low wind resource suitability.

As you know, meteorological towers are temporary tall structures (generally not exceeding 170 feet in height), which are installed at a site of a potential wind turbine project to assess the viability of the wind resource. The tower is generally equipped with specialized equipment (such as wind vanes, anemometers, and other weather sensors) at various distances above ground levels to measure and document various meteorological criteria which may determine the feasibility of a wind turbine project. Despite elevated national attention to this matter, wind turbines and associated meteorological towers have not been a factor for the users of the National Airspace System in Florida.

In large part, that is due to low wind resource suitability of the Sunshine State. The wind resource map obtained from the Wind Energy Resource Atlas of the United States shows the lowest wind resource estimate of' 1' over the state, with a handful of rare exceptions '2' in the coastal areas and in the Florida Keys.

As of the date of this letter, there was only one request for technical assistance related to a meteorological tower received by FOOT. Gulf Power Company notified FOOT in March 2009 of their intent to install and operate a 196-foot meteorological tower for a 2-year study of wind resources in Navarre Beach. They coordinated the request with federal, state, local, and military stakeholders, and even installed an obstruction light on the structure, which was beyond the requirements of the FAA Obstruction Marking and Lighting Advisory Circular.

No other requests or complaints from the National Airspace System users regarding unmarked meteorological towers have been received by FOOT directly or through other federal or local agencies.

As such, the NTSB recommendation that the State of Florida enacts legislation requiring meteorological towers to be marked and lighted, and registered in a directory serves a very limited role in requiring a provision of resource that is unlikely to be utilized by (or even familiar to) pilots during pre-flight planning.

-From Jeff Long, Commissioner of Tennessee Department of Safety & Homeland Security, and Governor’s Homeland Security Advisor: Thank you for the Safety Recommendation A-13-21 that requests Tennessee to enact legislation requiring that meteorological evaluation towers erected in your state or territory are marked and registered in a directory.

The Department has reviewed recommendation A-13-21 and consulted with our fellow state departments. Currently the state does produce aeronautical charts, but these charts would not be suitable for MET towers because they are infrequently published. The best way to address this issue would be to create a web based listing or map for MET tower locations.

It is the state's opinion that this would be most efficiently addressed by the FM. The FM already performs this function for obstacles over 200 feet. It would be safer and more efficient to have all hazards available in one source.

State flight services are not affected by MET Towers because the vast majority of operations are by fixed wing and conducted at altitudes well above 200 feet. The state will have to work with the industry to properly review the necessity of these changes. The Tennessee General Assembly returns to session in January 2020, and we will consult with interested parties to further consider this recommendation.

-From Trini Brassard, Assistant Director, Policy, Planning and Intermodal Development, Vermont Agency of Transportation: As the Assistant Director of the Policy, Planning and Intermodal Development Division here at the Vermont Agency of Transportation (VTrans) I work mostly with our Rail and Aviation Bureau. We received your December 2, 2019 letter to our Governor, Phil Scott regarding a Safety Recommendation A 13-21. First let me apologize for a delay in response. I was not aware of this recommendation nor were any of our staff.

We believe this is due to a change in staffing, but please know we take safety very seriously here and do not believe there has been any increase risk to our aviation community because of the delay.

Vermont has requirements on the construction of towers currently that vary depending on the type of tower being constructed (telecommunication, radio, meteorological, etc.). During the permitting phase of all towers, VTrans is notified of the project and we remind the permitting entity they need to get approval from the FAA through an obstruction evaluation using the FAA form 7460. This evaluation will advise if the tower needs to have lights on top, if it is too high for the airspace it is being constructed into or if it is not going to cause any conflict.

Each of the permitting entities manage public databases for the permits they issue, which is much more inclusive of all development types. There is no database strictly set up for meteorological towers. Inquiry into the volume of meteorological tower applications showed only one permit being issued in the past 10 years and it had an evaluation by FAA. At this time we do not see legislative changes warranted as our current requirements address the possible challenges between meteorological towers and aircraft.

They allow for VTrans and FAA to be involved in evaluating the proposed project and also allow us to make requirements on the developer such as lighting, shortening the tower, etc. to accommodate air traffic.

Thank you for bringing this outstanding item to our attention. Please let me know if you have any further questions.

-From Patrick K. McKenna, Director, Missouri Department of Transportation: I am in receipt of your letter to Governor Parson recommending the State of Missouri enact legislation requiring meteorological evaluation towers to be marked and registered in a directory.

Legislation was enacted in 2012 that requires the marking of any anemometer tower that is fifty feet above the ground or higher, is located outside the boundaries of any municipality, and whose appearance is not otherwise mandated by state or federal law, to be marked and painted per the statute (section 701 .550, Revised Statutes of Missouri). This statute appears to be in compliance with the NTSB's marking recommendation.

Missouri does not currently have legislation in place to create a directory of meteorological evaluation towers in the state. We will continue to work with aviation stakeholders to evaluate the need for a statewide directory, but at this time, we believe the marking legislation currently in place is sufficient and consistent with this safety recommendation.

-From Carlos M. Braceras, P.E., Executive Director, Department of Transportation, State of Utah: Governor Gary Herbert asked me to respond to your letter dated November 25, 2019, regarding Safety Recommendation A-13-21, meteorological evaluation tower safety.

We appreciate the work of the National Traffic Safety Board (NTSB) to identify risks associated with low-altitude aviation operations, specifically as it relates to unmarked meteorological evaluation towers. The Executive Branch of the State of Utah commits to work with the Utah State Legislature during the upcoming 2020 General Session to consider recommendations from the NTSB to enact legislation that ensures meteorological evaluation towers are marked and registered in a directory.

The State of Utah is committed to continue to support aviation safety and to take the recommendations of the NTSB under advisement.

-From Jeffrey DeCarlo, Administrator, MassDOT (Massachusetts Department of Transportation) Aeronautics Division: I am In receipt of your November 26, 20 1 9 letter addressed to Governor Charles Baker regarding the issuance by the NTSB (Board} of Safety Recommendation A-13-21 "as a result of our investigation of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people." You further state that "[we have not heard back from you [i.e., Governor Baker} regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter." A-13-21 recommends the enactment of state legislation to address the issue.

Unfortunately, this is the first time I have been made aware of the Board's recommendation, despite two previous letters. Be that as it may. let me assure the Board that the Aeronautics Division shares your concern regarding the towers and will immediately begin analyzing the local implications and what actions can be taken or planned to address this matter. Secondly, once our investigation is complete, we will update the Board electronically, as suggested, with the hope that this recommendation can be reclassified.

Thank you for your ardent support for the safety of our public use airports and for bringing this important matter to our attention.

We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have not received any additional information from you regarding any actions that you have completed or planned in response to this important safety issue. Pending our receipt of an update, Safety Recommendation A-13-21 remains classified OPEN--ACCEPTABLE RESPONSE.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 remains classified CLOSED--UNACCEPTABLE ACTION/ NO RESPONSE RECEIVED.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 remains classified CLOSED--UNACCEPTABLE ACTION/ NO RESPONSE RECEIVED.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 remains classified CLOSED--UNACCEPTABLE ACTION/ NO RESPONSE RECEIVED.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 remains classified CLOSED--UNACCEPTABLE ACTION/ NO RESPONSE RECEIVED.

-From Kevin A. Dillon, A.A.E., Executive Director, Connecticut Airport Authority: The Connecticut Airport Authority (CAA) is in receipt of your letter dated November 26, 2019 to Connecticut Governor Ned Lamont regarding Safety Recommendation A-13-21. In 2011, the Connecticut Airport Authority was created as an independent quasi-public agency to hold primary jurisdiction over aviation matters in the State of Connecticut. The formal transfer of aviation assets from the State to the CAA took place on July 1, 2013, which appears to be a few months after your initial correspondence to the State regarding A-13-21.

As the state's current authority over aviation matters, the CAA is pleased to follow up on this matter.

In 2018, after learning in late 2017 of correspondence between the NTSB and other Connecticut state agencies regarding A-13-21, the CAA pursued legislation to require marking of meteorological evaluation towers (METs). However, this effort was suspended once the FAA Reauthorization Act of 2018 was signed into law. As you know, this legislation required marking of METs between 50 and 200 feet, and it also required the FAA to develop a database that tracks such towers. In light of this federal action, the CAA assumed that such recommendation would be considered closed. However, please let us know if any further action is necessary.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 remains classified CLOSED--UNACCEPTABLE ACTION/ NO RESPONSE RECEIVED.

If you inform us, in a timely manner, of any responsive actions that you have taken or planned, we may consider reclassifying this recommendation. You may e-mail us any relevant updates at ExecutiveSecretariat@ntsb.gov. Please do not send an electronic and a hard copy of the same response.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 is classified CLOSED--UNACCEPTABLE ACTION/ NO RESPONSE RECEIVED.

If you inform us, in a timely manner, of any responsive actions that you have taken or planned, we may consider reclassifying this recommendation. You may e-mail us any relevant updates at ExecutiveSecretariat@ntsb.gov. Please do not send an electronic and a hard copy of the same response.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 is classified CLOSED--UNACCEPTABLE ACTION/ NO RESPONSE RECEIVED.

If you inform us, in a timely manner, of any responsive actions that you have taken or planned, we may consider reclassifying this recommendation. You may e-mail us any relevant updates at ExecutiveSecretariat@ntsb.gov. Please do not send an electronic and a hard copy of the same response.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 remains classified CLOSED--UNACCEPTABLE ACTION/ NO RESPONSE RECEIVED.

If you inform us, in a timely manner, of any responsive actions that you have taken or planned, we may consider reclassifying this recommendation. You may e-mail us any relevant updates at ExecutiveSecretariat@ntsb.gov. Please do not send an electronic and a hard copy of the same response.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 is classified CLOSED--UNACCEPTABLE ACTION/ NO RESPONSE RECEIVED.

If you inform us, in a timely manner, of any responsive actions that you have taken or planned, we may consider reclassifying this recommendation. You may e-mail us any relevant updates at ExecutiveSecretariat@ntsb.gov. Please do not send an electronic and a hard copy of the same response.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 is classified CLOSED--UNACCEPTABLE ACTION/ NO RESPONSE RECEIVED.

If you inform us, in a timely manner, of any responsive actions that you have taken or planned, we may consider reclassifying this recommendation. You may e-mail us any relevant updates at ExecutiveSecretariat@ntsb.gov. Please do not send an electronic and a hard copy of the same response.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 is classified CLOSED--UNACCEPTABLE ACTION/ NO RESPONSE RECEIVED.

If you inform us, in a timely manner, of any responsive actions that you have taken or planned, we may consider reclassifying this recommendation. You may e-mail us any relevant updates at ExecutiveSecretariat@ntsb.gov. Please do not send an electronic and a hard copy of the same response.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 is classified CLOSED--UNACCETABLE ACTION/ NO RESPONSE RECEIVED.

If you inform us, in a timely manner, of any responsive actions that you have taken or planned, we may consider reclassifying this recommendation. You may e-mail us any relevant updates at ExecutiveSecretariat@ntsb.gov. Please do not send an electronic and a hard copy of the same response.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 is classified CLOSED--UNACCEPTABLE ACTION/ NO RESPONSE RECEIVED.

If you inform us, in a timely manner, of any responsive actions that you have taken or planned, we may consider reclassifying this recommendation. You may e-mail us any relevant updates at ExecutiveSecretariat@ntsb.gov. Please do not send an electronic and a hard copy of the same response.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 is classified CLOSED--UNACCEPTABLE ACTION/ NO RESPONSE RECEIVED.

If you inform us, in a timely manner, of any responsive actions that you have taken or planned, we may consider reclassifying this recommendation. You may e-mail us any relevant updates at ExecutiveSecretariat@ntsb.gov. Please do not send an electronic and a hard copy of the same response.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 is classified CLOSED--UNACCEPTABLE ACTION/ NO RESPONSE RECEIVED.

If you inform us, in a timely manner, of any responsive actions that you have taken or planned, we may consider reclassifying this recommendation. You may e-mail us any relevant updates at ExecutiveSecretariat@ntsb.gov. Please do not send an electronic and a hard copy of the same response.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 is classified CLOSED--UNACCEPTABLE ACTION/ NO RESPONSE RECEIVED.

If you inform us, in a timely manner, of any responsive actions that you have taken or planned, we may consider reclassifying this recommendation. You may e-mail us any relevant updates at ExecutiveSecretariat@ntsb.gov. Please do not send an electronic and a hard copy of the same response.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 is classified CLOSED--UNACCEPTABLE ACTION/ NO RESPONSE RECEIVED.

If you inform us, in a timely manner, of any responsive actions that you have taken or planned, we may consider reclassifying this recommendation. You may e-mail us any relevant updates at ExecutiveSecretariat@ntsb.gov. Please do not send an electronic and a hard copy of the same response.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 remains classified CLOSED--UNACCEPTABLE ACTION/ NO RESPONSE RECEIVED.

If you inform us, in a timely manner, of any responsive actions that you have taken or planned, we may consider reclassifying this recommendation. You may e-mail us any relevant updates at ExecutiveSecretariat@ntsb.gov. Please do not send an electronic and a hard copy of the same response.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 remains classified CLOSED--UNACCEPTABLE ACTION/ NO RESPONSE RECEIVED.

If you inform us, in a timely manner, of any responsive actions that you have taken or planned, we may consider reclassifying this recommendation. You may e-mail us any relevant updates at ExecutiveSecretariat@ntsb.gov. Please do not send an electronic and a hard copy of the same response.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 remains classified CLOSED--UNACCEPTABLE ACTION/ NO RESPONSE RECEIVED.

If you inform us, in a timely manner, of any responsive actions that you have taken or planned, we may consider reclassifying this recommendation. You may e-mail us any relevant updates at ExecutiveSecretariat@ntsb.gov. Please do not send an electronic and a hard copy of the same response.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 remains classified CLOSED--UNACCEPTABLE ACTION/ NO RESPONSE RECEIVED.

If you inform us, in a timely manner, of any responsive actions that you have taken or planned, we may consider reclassifying this recommendation. You may e-mail us any relevant updates at ExecutiveSecretariat@ntsb.gov. Please do not send an electronic and a hard copy of the same response.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 is classified CLOSED--UNACCEPTABLE ACTION/ NO RESPONSE RECEIVED.

If you inform us, in a timely manner, of any responsive actions that you have taken or planned, we may consider reclassifying this recommendation. You may e-mail us any relevant updates at ExecutiveSecretariat@ntsb.gov. Please do not send an electronic and a hard copy of the same response.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 remains classified CLOSED--UNACCEPTABLE ACTION/ NO RESPONSE RECEIVED.

If you inform us, in a timely manner, of any responsive actions that you have taken or planned, we may consider reclassifying this recommendation. You may e-mail us any relevant updates at ExecutiveSecretariat@ntsb.gov. Please do not send an electronic and a hard copy of the same response.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 remains classified CLOSED--UNACCEPTABLE ACTION/ NO RESPONSE RECEIVED.

If you inform us, in a timely manner, of any responsive actions that you have taken or planned, we may consider reclassifying this recommendation. You may e-mail us any relevant updates at ExecutiveSecretariat@ntsb.gov. Please do not send an electronic and a hard copy of the same response.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 remains classified CLOSED--UNACCEPTABLE ACTION/ NO RESPONSE RECEIVED.

If you inform us, in a timely manner, of any responsive actions that you have taken or planned, we may consider reclassifying this recommendation. You may e-mail us any relevant updates at ExecutiveSecretariat@ntsb.gov. Please do not send an electronic and a hard copy of the same response.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 remains classified CLOSED--UNACCEPTABLE ACTION/NO RESPONSE RECEIVED.

If you inform us, in a timely manner, of any responsive actions that you have taken or planned, we may consider reclassifying this recommendation. You may e-mail us any relevant updates at ExecutiveSecretariat@ntsb.gov. Please do not send an electronic and a hard copy of the same response.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 remains classified CLOSED--UNACCEPTABLE ACTION/ NO RESPONSE RECEIVED.

If you inform us, in a timely manner, of any responsive actions that you have taken or planned, we may consider reclassifying this recommendation. You may e-mail us any relevant updates at ExecutiveSecretariat@ntsb.gov. Please do not send an electronic and a hard copy of the same response.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 remains classified CLOSED--UNACCEPTABLE ACTION/NO RESPONSE RECEIVED.

If you inform us, in a timely manner, of any responsive actions that you have taken or planned, we may consider reclassifying this recommendation. You may e-mail us any relevant updates at ExecutiveSecretariat@ntsb.gov. Please do not send an electronic and a hard copy of the same response.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 remains classified CLOSED--UNACCEPTABLE ACTION/ NO RESPONSE RECEIVED.

If you inform us, in a timely manner, of any responsive actions that you have taken or planned, we may consider reclassifying this recommendation. You may e-mail us any relevant updates at ExecutiveSecretariat@ntsb.gov. Please do not send an electronic and a hard copy of the same response.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 remains classified CLOSED--UNACCEPTABLE ACTION/ NO RESPONSE RECEIVED.

If you inform us, in a timely manner, of any responsive actions that you have taken or planned, we may consider reclassifying this recommendation. You may e-mail us any relevant updates at ExecutiveSecretariat@ntsb.gov. Please do not send an electronic and a hard copy of the same response.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 remains classified CLOSED--UNACCEPTABLE ACTION/ NO RESPONSE RECEIVED.

If you inform us, in a timely manner, of any responsive actions that you have taken or planned, we may consider reclassifying this recommendation. You may e-mail us any relevant updates at ExecutiveSecretariat@ntsb.gov. Please do not send an electronic and a hard copy of the same response.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 remains classified CLOSED--UNACCEPTABLE ACTION/ NO RESPONSE RECEIVED.

If you inform us, in a timely manner, of any responsive actions that you have taken or planned, we may consider reclassifying this recommendation. You may e-mail us any relevant updates at ExecutiveSecretariat@ntsb.gov. Please do not send an electronic and a hard copy of the same response.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 remains classified CLOSED--UNACCEPTABLE ACTION/NO RESPONSE RECEIVED.

If you inform us, in a timely manner, of any responsive actions that you have taken or planned, we may consider reclassifying this recommendation. You may e-mail us any relevant updates at ExecutiveSecretariat@ntsb.gov. Please do not send an electronic and a hard copy of the same response.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 remains classified CLOSED--UNACCEPTABLE ACTION/ NO RESPONSE RECEIVED.

If you inform us, in a timely manner, of any responsive actions that you have taken or planned, we may consider reclassifying this recommendation. You may e-mail us any relevant updates at ExecutiveSecretariat@ntsb.gov. Please do not send an electronic and a hard copy of the same response.

We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have not received any additional information from you regarding any actions that you have completed or planned in response to this important safety issue. Pending our receipt of an update, Safety Recommendation A-13-21 remains classified OPEN--ACCEPTABLE RESPONSE.

Please update us at ExecutiveSecretariat@ntsb.gov on your actions to address this recommendation, and do not send both an electronic and a hard copy of the same response.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 remains classified CLOSED--UNACCEPTABLE ACTION/ NO RESPONSE RECEIVED.

If you inform us, in a timely manner, of any responsive actions that you have taken or planned, we may consider reclassifying this recommendation. You may e-mail us any relevant updates at ExecutiveSecretariat@ntsb.gov. Please do not send an electronic and a hard copy of the same response.

We have not heard from you regarding this recommendation since it was issued, despite our August 3, 2017, follow-up letter. We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have yet to receive a response from you. Accordingly, Safety Recommendation A 13-21 is classified CLOSED--UNACCEPTABLE ACTION/ NO RESPONSE RECEIVED.

If you inform us, in a timely manner, of any responsive actions that you have taken or planned, we may consider reclassifying this recommendation. You may e-mail us any relevant updates at ExecutiveSecretariat@ntsb.gov. Please do not send an electronic and a hard copy of the same response.

We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have not received any additional information from you regarding any actions that you have completed or planned in response to this important safety issue. Pending our receipt of an update, Safety Recommendation A-13-21 remains classified OPEN--ACCEPTABLE RESPONSE.

Please update us at ExecutiveSecretariat@ntsb.gov on your actions to address this recommendation, and do not send both an electronic and a hard copy of the same response.

We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have not received any additional information from you regarding any actions that you have completed or planned in response to this important safety issue. Pending our receipt of an update, Safety Recommendation A-13-21 remains classified OPEN--ACCEPTABLE RESPONSE.

Please update us at ExecutiveSecretariat@ntsb.gov on your actions to address this recommendation, and do not send both an electronic and a hard copy of the same response.

We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have not received any additional information from you regarding any actions that you have completed or planned in response to this important safety issue. Pending our receipt of an update, Safety Recommendation A-13-21 remains classified OPEN--ACCEPTABLE RESPONSE.

Please update us at correspondence@ntsb.gov on your actions to address this recommendation, and do not send both an electronic and a hard copy of the same response.

We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have not received any additional information from you regarding any actions that you have completed or planned in response to this important safety issue. Pending our receipt of an update, Safety Recommendation A-13-21 remains classified OPEN--ACCEPTABLE RESPONSE.

Please update us at correspondence@ntsb.gov on your actions to address this recommendation, and do not send both an electronic and a hard copy of the same response.

We normally expect actions to address our recommendations to be completed within 3 to 5 years; however, it has now been more than 5 years since this recommendation was issued and we have not received any additional information from you regarding any actions that you have completed or planned in response to this important safety issue. Pending our receipt of an update, Safety Recommendation A-13-21 remains classified OPEN--ACCEPTABLE RESPONSE.

Please update us at ExecutiveSecretariat@ntsb.gov on your actions to address this recommendation, and do not send both an electronic and a hard copy of the same response.

We note that the MSP plans to work with the aviation operators in your state to identify a solution for this safety issue. We point out, however, that this recommendation asks for a requirement to mark and register METs in your state. Although we appreciate the MSP’s response, we are concerned that it does not have the authority to enact legislation, as recommended. Therefore, we encourage you to forward this recommendation to your state legislature for consideration. Pending our review of the recommended legislation, Safety Recommendation A 13-21 remains classified OPEN--AWAIT RESPONSE.

We believe that the law Colorado enacted in 2014 requiring towers 50 feet and taller to be marked and painted is responsive to the first part of this recommendation. We note, however, that you do not intend to address the second part of the recommendation, which asks that METs in your state be registered in a directory noting their locations. We remain concerned that, without a requirement to record the location of METs in your state, they will continue to pose a hazard to low-altitude aviation operations in Colorado.

However, because you have made it clear that your actions in response to this recommendation are complete, Safety Recommendation A-13-21 is classified CLOSED--UNACCEPTABLE ACTION.

-From Michael P. Lewis, Executive Director, Colorado Department of Transportation: On behalf of Governor Hickenlooper, we thank you again for your letters of August 3, 2017 and January 3, 2018 regarding NTSB safety recommendations A-13-21 and A-14-100 through 106. We remain committed to ensuring that Coloradans are safe when traveling and doing business in our great state. Governor Hickenlooper asked that we respond to further clarify his response to recommendation A-13-21.

As you recall, we have enacted recommendation A-13-21 through legislation, when we signed House Bill 14-1216 into law in 2014. This bill requires safety markings for certain towers over fifty feet in height that are located in unincorporated areas of the state, and has been incorporated into Colorado Revised Statutes (CRS) section 43-10-117. At this time, we believe that existing statute concerning meteorological evaluation towers (METs) is sufficient and consistent with the safety expectation of A-13-21 and our state's aviation system users. Marking METs has been, and continues to be, the only requirement that operators have expressed any interest in requiring in statute.

Nevertheless, we appreciate the NTSB's continued attention to this issue.

Again, thank you for your correspondence.

We are pleased to learn that South Dakota requires that anemometer towers 50 feet above ground level (AGL) and higher be marked, painted, flagged, or otherwise constructed to be recognizable in clear air during daylight hours. We believe this requirement is responsive to the first part of our recommendation.

Regarding the second part of our recommendation, you wrote that South Dakota does not intend to introduce any additional legislation that relates specifically to METs, but that you maintain a database of structures that are 200 feet AGL or higher. We are concerned, however, that many METs are built lower than 200 feet AGL and would therefore not be included in this database.

We believe that maintaining a directory of MET locations provides pilots with useful information and an added layer of protection in instances where environmental conditions may hamper visibility, such as at night. As the wind energy industry expands, MET deployment will also increase, and we are concerned that, without measures to record their locations, METs pose a continuing hazard to low-altitude aviation operations. Therefore, we encourage you to also require that the METs in your state be registered. Pending the completion of this final action, Safety Recommendation A-13-21 is classified OPEN--ACCEPTABLE RESPONSE.

-From Major Christopher Grotton, Maine State Police, Support Services Division: This letter is in response to the NTSB Safety Recommendations A-13-21 and A-14-100 through -106 issued to the State of Maine in an August 2017 letter to Governor LePage.

The Maine State Police Air Wing has a small profile within the overall scope of aviation operations conducted within the State of Maine. We have two fixed wing aircraft in our inventory with no rotary wing asset.

Our core mission is primarily traffic related flights which are conducted during the daylight and in VFR conditions only. Any night VFR or day/night IFR flights that are requested would typically be administrative in nature and would be conducted operating under part 91 regulations.

When requested, we assist other aviation assets and agencies within the state under the conditions that the flight can be done within the confines of our Standard Operating Procedures Manual and our General Orders that pertains to the Air Wing.

Any search and rescue mission that we would be involved in would be conducted during daylight VFR only conditions. Our aircraft are equipped with wheels only and are not allowed to perform "off-site" landings.

We are restricted to published airports only. Those flights would also be conducted utilizing part 91 regulations.

I am in hopes that this information provides some context for our air operations and the applicability of the recommendations in your August 2017 letter. Our responses (below) to each of your recommendations are crafted within the context of our mission.

Our department will explore the progress of other aviation assets within the state, to include civilian assets like Life Flight, to address this problem and will work with them to identify possible solutions.

We believe that your efforts to encourage wind turbine operators and MET installers in your state to voluntarily publish the location and elevation of their METs is positive. Further, we are encouraged that your Bureau of Aviation has developed an interactive hazards map for pilots that includes information on tall towers and known METs and is available via the bureau’s website. We are concerned, however, that because there is no requirement for METs in your state to be registered, the interactive map may be misleading.

The speed with which METs can be erected is an important aspect of this safety issue; in just a matter of hours, the navigable airspace for low flying operations can change without notice. In addition, as the wind energy industry expands, MET deployment will also increase and, without measures to enhance their conspicuity and record their locations, METs pose a continuing hazard to low-altitude aviation operations in your state. Therefore, we encourage you to enact the recommended legislation. Pending completion of the recommended actions, Safety Recommendation A-13-21 is classified OPEN--ACCEPTABLE RESPONSE.

We note that you plan to work with industry stakeholders to determine if legislation that requires METs to be registered and marked is justified. We point out that, as the wind energy industry expands, MET deployment will also increase and, without measures to enhance their conspicuity and record their locations, METs pose a continuing hazard to low-altitude aviation operations in your state. Therefore, we encourage you to enact the recommended legislation. Pending completion of that action, Safety Recommendation A-13-21 is classified OPEN--ACCEPTABLE RESPONSE.

We are pleased to learn that, in 2014, Colorado enacted a law to require that towers 50 feet and taller be marked and painted. We believe this law is responsive to the first part of this recommendation; however, we would also like to know how you intend to address the second part of this recommendation, which asks that METs in your state be registered in a directory noting their locations. We believe that maintaining a directory of MET locations provides pilots with useful information and an added layer of protection in instances where environmental conditions may hamper visibility (such as at night).

Pending the completion of this final action, Safety Recommendation A-13-21 is classified OPEN--ACCEPTABLE RESPONSE.

We believe that your efforts to work with the Arkansas Aerial Applicators Association to educate agricultural pilots about the dangers of METs and best practices to avoid them are positive. However, as the wind energy industry expands, MET deployment will also increase and, without measures to enhance their conspicuity and record their locations, METs pose a continuing hazard to low-altitude aviation operations in your state. Therefore, we encourage you to enact the recommended legislation. Pending completion of the recommended actions, Safety Recommendation A-13-21 is classified OPEN—ACCEPTABLE RESPONSE.

We are pleased to learn that, in 2012, Idaho enacted a law to require that temporary or permanent guyed towers 50 feet and taller be lighted, marked, and painted. We note that a “guyed tower” is defined as a tower that is supported in whole or in part by guy wires and ground anchors or other means of support besides the superstructure of the tower itself, and includes METs. We believe this requirement is responsive to the first part of this recommendation.

In response to the second part of this recommendation, you wrote that you do not intend to require that all METs in your state be registered in a directory noting their locations. Although your efforts to communicate regularly with aerial applicators in Idaho are a positive step, we believe that maintaining a directory of MET locations provides pilots with useful information and an added layer of protection in instances where environmental conditions may hamper visibility (such as at night).

As the wind energy industry expands, MET deployment will also increase, and we are concerned that, without measures to record their locations, METs pose a continuing hazard to low-altitude aviation operations. Therefore, we encourage you to require that the METs in your state be registered. Pending the completion of this final action, Safety Recommendation A-13-21 is classified OPEN—ACCEPTABLE RESPONSE.

-From Dennis Daugaard, Governor of South Dakota: With regard to recommendation A-13-21, South Dakota is one of a handful of states that already requires wind measurement towers1 fifty feet above the ground and taller to be clearly marked. South Dakota Codified Law 50-9•13 reads as follows: Any anemometer tower that is fifty feet in height above the ground or higher, that is located outside the exterior boundaries of any municipality, and whose appearance is not otherwise mandated by state or federal law shall be marked, painted, flagged, or otherwise constructed to be recognizable in clear air during daylight hours.

Any anemometer tower that was erected before July 1, 2010 shall be marked as required in this section within one year after July 1, 2010. Any anemometer tower that is erected on or after July 1, 2010 shall be marked as required in this section at' the time it is erected. Marking required under this section includes marking ~he anemometer tower, guy wires, and accessory facilities as follows: (1) The top one-third of the anemometer tower shall be painted in equal; alternating bands' of aviation range and white, beginning with orange at the top of the' tower and ending with orange at the bottom of the marked portion of the tower;

(2) Two marker balls shall be attached to and evenly spaced on each of the outside guy wires; (3) The area surrounding each point where a guy wire is anchored to the ground shall have a contrasting appearance with any surrounding vegetation. If the adjacent land is grazed, the area surrounding the anchor point shall be fenced. For purposes of this section, the term, area surrounding the anchor point, means an area not Jess than sixty-four square feet whose outer boundary is at least four feet from the anchor point; and (4) One or more seven-foot safety sleeves shall be placed at each anchor point and shall extend from the anchor point along each guy wire attached to the anchor point.

A violation of this section is a Class 2 misdemeanor.

In addition to this statutory requirement, the South Dakota Aeronautics Commission regulates the construction and alteration of structures based on height or proximity to air navigation facilities. South Dakota Codified Law 50-9-1 currently states: Any person or organization who intends to construct or alter a structure shall submit an application and obtain an approval permit from the commission for any construction or alteration that: (1) Exceeds two hundred feet above ground level;

(2) Is within twenty thousand feet of a state approved public airport or military airport that has at least one runway more than three thousand two hundred feet in actual length and the construction or alteration exceeds a one hundred to one surface ratio from any point on the runway; (3) Is within ten thousand feet of a state approved public airport or military airport that has its longest runway no more than three thousand two hundred feet in actual length and the construction or alteration exceeds a fifty to one surface ratio from any point on the runway;

-Leslie S. Richards, Secretary Department of Transportation, Commonwealth of Pennsylvania: A-13-21 was issued as a result of NTSB investigations of three accidents which airplanes inadvertently collided with meteorological evaluation towers (MET), fatally injuring four people.

To date, Pennsylvania has not enacted legislation pertaining to marking and registration of MET towers. However, the Bureau of Aviation has established an interactive hazards map for pilots on their website, to depict both tall towers registered with the FAA and known MET towers erected in Pennsylvania. Wind turbine operators and MET tower installers were contacted and encouraged to voluntarily publish the location and elevation of their towers. The interactive MET towers and Tall Structures Map can be viewed at: http://padotgis.maps.arcgis.com/apps/Publiclnformation/index.html?appid=e5430a7ca97945d894eb22edf0871 a7f

-From John W. Hickenlooper, Governor: We have enacted recommendation A-13- 21 through legislation, when we signed House Bill 14-1216 into law in 2014. This bill requires safety markings for certain towers over 50 feet in height that are located in unincorporated areas of the state, and has been incorporated into Colorado Revised Statutes (CRS) section 43-10-117.

Specifically, CRS 43-10- 117 requires: (2) Where the appearance of a tower is not otherwise governed by state or federal law, rule, or regulation, any tower over fifty feet in height that is located outside the boundaries of an incorporated city or town on land that is primarily rural or undeveloped or used for agricultural purposes must be marked and painted or otherwise constructed to be visible in clear air during daylight hours from a distance of not less than two thousand feet. Towers must also comply with the following additional requirements: (a) A tower must be painted in equal alternating bands of aviation orange and white, beginning with orange at the top of the tower;

(b) One marker ball must be attached to the top third of each outside guy wire; and (c) Guy wires must have a seven-foot- long safety sleeve at each anchor point that extends from the anchor point along each guy wire attached to the anchor point. (3) Any tower that was erected prior to August 6, 2014, must be marked as required by the provisions of this section within one year of August 6, 2014. Any tower that is erected on or after August 6, 2014, must be marked as required by this section at the time it is erected.

The Colorado Army National Guard operates helicopters that are used in search and rescue missions, and they report that compliance with all recommendations as outlined in your document of August 3, 2017, as it pertains to the operation of helicopters.

Finally, the Colorado State Patrol currently implements recommendation A-14-101, using procedures and avionics that allow for up-to-date weather information and assistance with flight risk assessment decisions. While they do not operate helicopters in search and rescue missions, they are considering implementing recommendations A-14-100, A-14-105, and A-14-106 following an independent and unrelated safety audit they are conducting. Once completed, we will incorporate regulations that are in compliance with the NTSB recommendation, at a minimum.

Again, thank you for your correspondence regarding this issue. Please don’t hesitate to reach out to my Office should you have any further questions.

-From Matthew Clark, Transportation Policy Advisor to Governor Doug Ducey: The State of Arizona will work with industry stakeholders who will evaluate the need for legislation that requires MET's in Arizona to be marked and registered in a directory.

Terry S. Miyauchi, Aviation Administrator, Arizona Department of Public Safety: The purpose of this letter is to respond to your safety recommendations letter addressed to Governor Doug Ducey, dated August 3, 2017. In that letter, NTSB Safety Recommendations A-13-21 (meteorological evaluation towers) andA-14-100 through 106 (search-and-rescue flight) were provided to the State of Arizona. The Arizona Department of Public Safety (AZDPS) conducts flights across the entire state of Arizona, to include areas where meteorological towers have been erected. Approximately 25% percent of all flights for AZDPS and the State are in support of search and rescue operations.

We value the goal of aviation safety as the number one priority for all of our aviation activity and your recommendations are well received. We offer the following specific responses to each of your NTSB recommendations:

Response to A-13-21 will be responded to in a separate correspondence given that A-13-21 includes specific legislative recommendations.

-From Asa Hutchinson, Governor: While we understand the safety concerns regarding Meteorological Evaluation Towers (MET Towers), Arkansas has had no issue with these structures for several years. The State of Arkansas has worked with the Arkansas Aerial Applicators Association (AAAA) to educate agricultural pilots about the dangers of Met Towers and best practices to avoid them. In addition, in June 2011, the FAA issued Advisory Circular 70/7460-1K concerning guidelines for marking of MET and issued a policy letter supporting the use of the guidelines issued in the AC.

Many states have passed legislation regulating MET towers, and the State of Arkansas believes this issue is best resolved at a national level.

-From Mark Lessor, Aviation Technician, Idaho Transportation Department, Idaho Division of Aeronautics: As a response to the letter from the NTSB to Governor Otter dated August 3, 2017, and as verbally promised last week, here is a brief summary of actions taken by the State of Idaho in response to the aviation hazards presented by the recent influx of met towers in our state.

First the Idaho law, enacted in 2012: TITLE 21 AERONAUTICS CHAPTER 5 AIRPORT ZONING ACT 21-515A. HAZARDS TO AIR FLIGHT — STANDARDS FOR GUYED TOWERS. (1) Any temporary or permanent guyed tower fifty (50) feet or more in height that is located outside the boundaries of an incorporated city or town on land that is primarily rural or undeveloped or used for agricultural purposes, or that is primarily desert, and where such guyed tower’s appearance is not otherwise governed by state or federal law, rule or regulation, shall be lighted, marked and painted or otherwise constructed to be visible in clear air during daylight hours from a distance of not less than two thousand (2,000) feet.

Guyed towers shall be required to be in accordance with the following: (a) Guyed towers shall be painted in seven equal alternating bands of aviation orange and white. Such alternating bands shall begin with orange at the top of the tower and end with orange at the base. (b) Guyed towers shall have a flashing light at the top of the tower. Such light shall be visible in clear air, with the naked eye, from a distance of two thousand (2,000) feet when flashing. Such light shall also be visible with night vision goggles. (c) The surface area under the footprint of the tower and six (6) feet beyond the outer tower anchors shall have a contrasting appearance with any surrounding vegetation.

(d) Two (2) marker balls shall be attached to and evenly spaced on each of the outside guy wires. (e) Guyed towers shall have a seven (7) foot long safety sleeve at each anchor point and shall extend from the anchor point along each guy wire attached to the anchor point. (2) Any guyed tower that was erected prior to the effective date of this act shall be marked as required by the provisions of this section within one (1) year of the effective date of this act. Any guyed tower that is erected on or after the effective date of this act shall be marked as required by the provisions of this section at the time it is erected.

(3) For the purposes of this section, the following terms shall have the following meanings: (a) "Guyed tower"

We issued A-13-21 to American Samoa on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing this recommendation, which was issued more than 4 years ago.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement this recommendation; until then, this recommendation will retain its current classification of OPEN—AWAIT RESPONSE.

For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter.

We issued A-13-21 to the US Virgin Islands on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing this recommendation, which was issued more than 4 years ago.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement this recommendation; until then, this recommendation will retain its current classification of OPEN—AWAIT RESPONSE.

For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter.

We issued A-13-21 to the commonwealth of the Northern Mariana Islands on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing this recommendation, which was issued more than 4 years ago.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement this recommendation; until then, this recommendation will retain its current classification of OPEN—AWAIT RESPONSE.

For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter.

This letter addresses NTSB Safety Recommendations A-13 21 and A-14-100 through -106. We issued A-13-21 to the District of Columbia on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people.

We issued A-14-100 through -106 to the District of Columbia on November 24, 2014, as a result of our investigation of the March 30, 2013, accident in which a Eurocopter AS350 B3 helicopter, operated by the Alaska Department of Public Safety, impacted terrain while maneuvering during a search-and-rescue flight near Talkeetna, Alaska.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing these recommendations, which were issued more than 4 and 2 years ago, respectively.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement these recommendations; until then, these recommendations will retain their current classification of OPEN—AWAIT RESPONSE.

For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter. For additional background information about Safety Recommendations A-14-100 through -106, please refer to pages 54 through 63 of our Alaska Department of Public Safety Eurocopter accident report.

We issued A-13-21 to the commonwealth of Puerto Rico on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing this recommendation, which was issued more than 4 years ago.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement this recommendation; until then, this recommendation will retain its current classification of OPEN—AWAIT RESPONSE.

For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter.

We issued A-13-21 to the state of Vermont on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing this recommendation, which was issued more than 4 years ago.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement this recommendation; until then, this recommendation will retain its current classification of OPEN—AWAIT RESPONSE.

For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter.

We issued A-13-21 to the state of Rhode Island on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing this recommendation, which was issued more than 4 years ago.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement this recommendation; until then, this recommendation will retain its current classification of OPEN—AWAIT RESPONSE.

For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter.

This letter addresses NTSB Safety Recommendations A-13 21 and A-14-100 through -106. We issued A-13-21 to the commonwealth of Virginia on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people.

We issued A-14-100 through -106 to the commonwealth of Virginia on November 24, 2014, as a result of our investigation of the March 30, 2013, accident in which a Eurocopter AS350 B3 helicopter, operated by the Alaska Department of Public Safety, impacted terrain while maneuvering during a search-and-rescue flight near Talkeetna, Alaska.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing these recommendations, which were issued more than 4 and 2 years ago, respectively.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement these recommendations; until then, these recommendations will retain their current classification of OPEN—AWAIT RESPONSE.

For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter. For additional background information about Safety Recommendations A-14-100 through -106, please refer to pages 54 through 63 of our Alaska Department of Public Safety Eurocopter accident report.

We issued A-13-21 to the state of Ohio on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing this recommendation, which was issued more than 4 years ago.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement this recommendation; until then, this recommendation will retain its current classification of OPEN—AWAIT RESPONSE.

For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing this recommendation, which was issued more than 4 years ago.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement this recommendation; until then, this recommendation will retain its current classification of OPEN—AWAIT RESPONSE.

This letter addresses NTSB Safety Recommendations A-13 21 and A-14-100 through -106. We issued A-13-21 to the state of New Mexico on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people.

We issued A-14-100 through -106 to the state of New Mexico on November 24, 2014, as a result of our investigation of the March 30, 2013, accident in which a Eurocopter AS350 B3 helicopter, operated by the Alaska Department of Public Safety, impacted terrain while maneuvering during a search-and-rescue flight near Talkeetna, Alaska.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing these recommendations, which were issued more than 4 and 2 years ago, respectively.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement these recommendations; until then, these recommendations will retain their current classification of OPEN—AWAIT RESPONSE.

For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter. For additional background information about Safety Recommendations A-14-100 through -106, please refer to pages 54 through 63 of our Alaska Department of Public Safety Eurocopter accident report.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing this recommendation, which was issued more than 4 years ago.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement this recommendation; until then, this recommendation will retain its current classification of OPEN—AWAIT RESPONSE.

This letter addresses NTSB Safety Recommendations A-13 21 and A-14-100 through -106. We issued A-13-21 to the state of New Hampshire on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people.

We issued A-14-100 through -106 to the state of New Hampshire on November 24, 2014, as a result of our investigation of the March 30, 2013, accident in which a Eurocopter AS350 B3 helicopter, operated by the Alaska Department of Public Safety, impacted terrain while maneuvering during a search-and-rescue flight near Talkeetna, Alaska.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing these recommendations, which were issued more than 4 and 2 years ago, respectively.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement these recommendations; until then, these recommendations will retain their current classification of OPEN—AWAIT RESPONSE.

For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter. For additional background information about Safety Recommendations A-14-100 through -106, please refer to pages 54 through 63 of our Alaska Department of Public Safety Eurocopter accident report.

This letter addresses NTSB Safety Recommendations A-13 21 and A-14-100 through -106. We issued A-13-21 to the state of Missouri on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people.

We issued A-14-100 through -106 to the state of Missouri on November 24, 2014, as a result of our investigation of the March 30, 2013, accident in which a Eurocopter AS350 B3 helicopter, operated by the Alaska Department of Public Safety, impacted terrain while maneuvering during a search-and-rescue flight near Talkeetna, Alaska.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing these recommendations, which were issued more than 4 and 2 years ago, respectively.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement these recommendations; until then, these recommendations will retain their current classification of OPEN—AWAIT RESPONSE.

For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter. For additional background information about Safety Recommendations A-14-100 through -106, please refer to pages 54 through 63 of our Alaska Department of Public Safety Eurocopter accident report.

This letter addresses NTSB Safety Recommendations A-13 21 and A-14-100 through -106. We issued A-13-21 to the state of Mississippi on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people.

We issued A-14-100 through -106 to the state of Mississippi on November 24, 2014, as a result of our investigation of the March 30, 2013, accident in which a Eurocopter AS350 B3 helicopter, operated by the Alaska Department of Public Safety, impacted terrain while maneuvering during a search-and-rescue flight near Talkeetna, Alaska.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing these recommendations, which were issued more than 4 and 2 years ago, respectively.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement these recommendations; until then, these recommendations will retain their current classification of OPEN—AWAIT RESPONSE.

For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter. For additional background information about Safety Recommendations A-14-100 through -106, please refer to pages 54 through 63 of our Alaska Department of Public Safety Eurocopter accident report.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing this recommendation, which was issued more than 4 years ago.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement this recommendation; until then, this recommendation will retain its current classification of OPEN—AWAIT RESPONSE.

This letter addresses NTSB Safety Recommendations A-13 21 and A-14-100 through -106. We issued A-13-21 to the state of Maine on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people.

We issued A-14-100 through -106 to the state of Maine on November 24, 2014, as a result of our investigation of the March 30, 2013, accident in which a Eurocopter AS350 B3 helicopter, operated by the Alaska Department of Public Safety, impacted terrain while maneuvering during a search-and-rescue flight near Talkeetna, Alaska.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing these recommendations, which were issued more than 4 and 2 years ago, respectively.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement these recommendations; until then, these recommendations will retain their current classification of OPEN—AWAIT RESPONSE.

For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter. For additional background information about Safety Recommendations A-14-100 through -106, please refer to pages 54 through 63 of our Alaska Department of Public Safety Eurocopter accident report.

This letter addresses NTSB Safety Recommendations A-13 21 and A-14-100 through -106. We issued A-13-21 to the commonwealth of Massachusetts on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people.

We issued A-14-100 through -106 to the commonwealth of Massachusetts on November 24, 2014, as a result of our investigation of the March 30, 2013, accident in which a Eurocopter AS350 B3 helicopter, operated by the Alaska Department of Public Safety, impacted terrain while maneuvering during a search-and-rescue flight near Talkeetna, Alaska.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing these recommendations, which were issued more than 4 and 2 years ago, respectively.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement these recommendations; until then, these recommendations will retain their current classification of OPEN—AWAIT RESPONSE.

For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter. For additional background information about Safety Recommendations A-14-100 through -106, please refer to pages 54 through 63 of our Alaska Department of Public Safety Eurocopter accident report.

This letter addresses NTSB Safety Recommendations A-13 21 and A-14-100 through -106. We issued A-13-21 to the state of Louisiana on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people.

We issued A-14-100 through -106 to the state of Louisiana on November 24, 2014, as a result of our investigation of the March 30, 2013, accident in which a Eurocopter AS350 B3 helicopter, operated by the Alaska Department of Public Safety, impacted terrain while maneuvering during a search-and-rescue flight near Talkeetna, Alaska.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing these recommendations, which were issued more than 4 and 2 years ago, respectively.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement these recommendations; until then, these recommendations will retain their current classification of OPEN—AWAIT RESPONSE.

For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter. For additional background information about Safety Recommendations A-14-100 through -106, please refer to pages 54 through 63 of our Alaska Department of Public Safety Eurocopter accident report.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing this recommendation, which was issued more than 4 years ago.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement this recommendation; until then, this recommendation will retain its current classification of OPEN—AWAIT RESPONSE.

This letter addresses NTSB Safety Recommendations A-13 21 and A-14-100 through -106. We issued A-13-21 to the state of Indiana on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people.

We issued A-14-100 through -106 to the state of Indiana on November 24, 2014, as a result of our investigation of the March 30, 2013, accident in which a Eurocopter AS350 B3 helicopter, operated by the Alaska Department of Public Safety, impacted terrain while maneuvering during a search-and-rescue flight near Talkeetna, Alaska.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing these recommendations, which were issued more than 4 and 2 years ago, respectively.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement these recommendations; until then, these recommendations will retain their current classification of OPEN—AWAIT RESPONSE.

For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter. For additional background information about Safety Recommendations A-14-100 through -106, please refer to pages 54 through 63 of our Alaska Department of Public Safety Eurocopter accident report.

We issued A-13-21 to the state of Illinois on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing this recommendation, which was issued more than 4 years ago.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement this recommendation; until then, this recommendation will retain its current classification of OPEN—AWAIT RESPONSE.

For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter.

We issued A-13-21 to the state of Idaho on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing this recommendation, which was issued more than 4 years ago.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement this recommendation; until then, this recommendation will retain its current classification of OPEN—AWAIT RESPONSE.

For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing this recommendation, which was issued more than 4 years ago.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement this recommendation; until then, this recommendation will retain its current classification of OPEN—AWAIT RESPONSE.

We issued A-13-21 to the state of Florida on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing this recommendation, which was issued more than 4 years ago.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement this recommendation; until then, this recommendation will retain its current classification of OPEN—AWAIT RESPONSE.

For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing this recommendation, which was issued more than 4 years ago.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement this recommendation; until then, this recommendation will retain its current classification of OPEN—AWAIT RESPONSE.

This letter addresses NTSB Safety Recommendations A-13 21 and A-14-100 through -106. We issued A-13-21 to the state of Connecticut on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people.

We issued A-14-100 through -106 to the state of Connecticut on November 24, 2014, as a result of our investigation of the March 30, 2013, accident in which a Eurocopter AS350 B3 helicopter, operated by the Alaska Department of Public Safety, impacted terrain while maneuvering during a search-and-rescue flight near Talkeetna, Alaska.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing these recommendations, which were issued more than 4 and 2 years ago, respectively.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement these recommendations; until then, these recommendations will retain their current classification of OPEN—AWAIT RESPONSE.

For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter. For additional background information about Safety Recommendations A-14-100 through -106, please refer to pages 54 through 63 of our Alaska Department of Public Safety Eurocopter accident report.

This letter addresses NTSB Safety Recommendations A-13 21 and A-14-100 through -106. We issued A-13-21 to the state of Colorado on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people.

We issued A-14-100 through -106 to the state of Colorado on November 24, 2014, as a result of our investigation of the March 30, 2013, accident in which a Eurocopter AS350 B3 helicopter, operated by the Alaska Department of Public Safety, impacted terrain while maneuvering during a search-and-rescue flight near Talkeetna, Alaska.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing these recommendations, which were issued more than 4 and 2 years ago, respectively.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement these recommendations; until then, these recommendations will retain their current classification of OPEN—AWAIT RESPONSE.

For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter. For additional background information about Safety Recommendations A-14-100 through -106, please refer to pages 54 through 63 of our Alaska Department of Public Safety Eurocopter accident report.

This letter addresses NTSB Safety Recommendations A-13 21 and A-14-100 through -106. We issued A-13-21 to the state of California on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people.

We issued A-14-100 through -106 to the state of California on November 24, 2014, as a result of our investigation of the March 30, 2013, accident in which a Eurocopter AS350 B3 helicopter, operated by the Alaska Department of Public Safety, impacted terrain while maneuvering during a search-and-rescue flight near Talkeetna, Alaska.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing these recommendations, which were issued more than 4 and 2 years ago, respectively.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement these recommendations; until then, these recommendations will retain their current classification of OPEN—AWAIT RESPONSE.

For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter. For additional background information about Safety Recommendations A-14-100 through -106, please refer to pages 54 through 63 of our Alaska Department of Public Safety Eurocopter accident report.

This letter addresses NTSB Safety Recommendations A-13 21 and A-14-100 through -106. We issued A-13-21 to the state of Arkansas on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people.

We issued A-14-100 through -106 to the state of Arkansas on November 24, 2014, as a result of our investigation of the March 30, 2013, accident in which a Eurocopter AS350 B3 helicopter, operated by the Alaska Department of Public Safety, impacted terrain while maneuvering during a search-and-rescue flight near Talkeetna, Alaska.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing these recommendations, which were issued more than 4 and 2 years ago, respectively.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement these recommendations; until then, these recommendations will retain their current classification of OPEN—AWAIT RESPONSE.

For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter. For additional background information about Safety Recommendations A-14-100 through -106, please refer to pages 54 through 63 of our Alaska Department of Public Safety Eurocopter accident report.

This letter addresses NTSB Safety Recommendations A-13 21 and A-14-100 through -106. We issued A-13-21 to the state of Arizona on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people.

We issued A-14-100 through -106 to the state of Arizona on November 24, 2014, as a result of our investigation of the March 30, 2013, accident in which a Eurocopter AS350 B3 helicopter, operated by the Alaska Department of Public Safety, impacted terrain while maneuvering during a search-and-rescue flight near Talkeetna, Alaska.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing these recommendations, which were issued more than 4 and 2 years ago, respectively.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement these recommendations; until then, these recommendations will retain their current classification of OPEN—AWAIT RESPONSE.

For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter. For additional background information about Safety Recommendations A-14-100 through -106, please refer to pages 54 through 63 of our Alaska Department of Public Safety Eurocopter accident report.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing this recommendation, which was issued more than 4 years ago.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement this recommendation; until then, this recommendation will retain its current classification of OPEN—AWAIT RESPONSE.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing this recommendation, which was issued more than 4 years ago.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement this recommendation; until then, this recommendation will retain its current classification of OPEN--AWAIT RESPONSE.

This letter addresses NTSB Safety Recommendations A-13 21 and A-14-100 through -106. We issued A-13-21 to the state of Wisconsin on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people.

We issued A-14-100 through -106 to the state of Wisconsin on November 24, 2014, as a result of our investigation of the March 30, 2013, accident in which a Eurocopter AS350 B3 helicopter, operated by the Alaska Department of Public Safety, impacted terrain while maneuvering during a search-and-rescue flight near Talkeetna, Alaska.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing these recommendations, which were issued more than 4 and 2 years ago, respectively.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement these recommendations; until then, these recommendations will retain their current classification of OPEN—AWAIT RESPONSE.

For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter. For additional background information about Safety Recommendations A-14-100 through -106, please refer to pages 54 through 63 of our Alaska Department of Public Safety Eurocopter accident report.

This letter addresses NTSB Safety Recommendations A-13 21 and A-14-100 through -106. We issued A-13-21 to the state of Tennessee on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people.

We issued A-14-100 through -106 to the state of Tennessee on November 24, 2014, as a result of our investigation of the March 30, 2013, accident in which a Eurocopter AS350 B3 helicopter, operated by the Alaska Department of Public Safety, impacted terrain while maneuvering during a search-and-rescue flight near Talkeetna, Alaska.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing these recommendations, which were issued more than 4 and 2 years ago, respectively.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement these recommendations; until then, these recommendations will retain their current classification of OPEN—AWAIT RESPONSE.

For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter. For additional background information about Safety Recommendations A-14-100 through -106, please refer to pages 54 through 63 of our Alaska Department of Public Safety Eurocopter accident report.

This letter addresses NTSB Safety Recommendations A-13 21 and A-14-100 through -106. We issued A-13-21 to the state of South Dakota on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people.

We issued A-14-100 through -106 to the state of South Dakota on November 24, 2014, as a result of our investigation of the March 30, 2013, accident in which a Eurocopter AS350 B3 helicopter, operated by the Alaska Department of Public Safety, impacted terrain while maneuvering during a search-and-rescue flight near Talkeetna, Alaska.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing these recommendations, which were issued more than 4 and 2 years ago, respectively.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement these recommendations; until then, these recommendations will retain their current classification of “Open—Await Response.”

For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter. For additional background information about Safety Recommendations A-14-100 through -106, please refer to pages 54 through 63 of our Alaska Department of Public Safety Eurocopter accident report.

This letter addresses NTSB Safety Recommendations A-13 21 and A-14-100 through -106. We issued A-13-21 to the state of South Carolina on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people.

We issued A-14-100 through -106 to the state of South Carolina on November 24, 2014, as a result of our investigation of the March 30, 2013, accident in which a Eurocopter AS350 B3 helicopter, operated by the Alaska Department of Public Safety, impacted terrain while maneuvering during a search-and-rescue flight near Talkeetna, Alaska.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing these recommendations, which were issued more than 4 and 2 years ago, respectively.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement these recommendations; until then, these recommendations will retain their current classification of OPEN—AWAIT RESPONSE.

For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter. For additional background information about Safety Recommendations A-14-100 through -106, please refer to pages 54 through 63 of our Alaska Department of Public Safety Eurocopter accident report.

This letter addresses NTSB Safety Recommendations A-13 21 and A-14-100 through -106. We issued A-13-21 to the commonwealth of Pennsylvania on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people.

We issued A-14-100 through -106 to the commonwealth of Pennsylvania on November 24, 2014, as a result of our investigation of the March 30, 2013, accident in which a Eurocopter AS350 B3 helicopter, operated by the Alaska Department of Public Safety, impacted terrain while maneuvering during a search-and-rescue flight near Talkeetna, Alaska.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing these recommendations, which were issued more than 4 and 2 years ago, respectively.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement these recommendations; until then, these recommendations will retain their current classification of OPEN—AWAIT RESPONSE.

For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter. For additional background information about Safety Recommendations A-14-100 through -106, please refer to pages 54 through 63 of our Alaska Department of Public Safety Eurocopter accident report.

This letter addresses NTSB Safety Recommendations A-13 21 and A-14-100 through -106. We issued A-13-21 to the state of Oregon on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people. We issued A-14-100 through -106 to the state of Oregon on November 24, 2014, as a result of our investigation of the March 30, 2013, accident in which a Eurocopter AS350 B3 helicopter, operated by the Alaska Department of Public Safety, impacted terrain while maneuvering during a search-and-rescue flight near Talkeetna, Alaska.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing these recommendations, which were issued more than 4 and 2 years ago, respectively.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement these recommendations; until then, these recommendations will retain their current classification of “Open—Await Response.” For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter. For additional background information about Safety Recommendations A-14-100 through -106, please refer to pages 54 through 63 of our Alaska Department of Public Safety Eurocopter accident report.

This letter addresses NTSB Safety Recommendations A-13 21 and A-14-100 through -106. We issued A-13-21 to the state of Nevada on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people.

We issued A-14-100 through -106 to the state of Nevada on November 24, 2014, as a result of our investigation of the March 30, 2013, accident in which a Eurocopter AS350 B3 helicopter, operated by the Alaska Department of Public Safety, impacted terrain while maneuvering during a search-and-rescue flight near Talkeetna, Alaska.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing these recommendations, which were issued more than 4 and 2 years ago, respectively.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement these recommendations; until then, these recommendations will retain their current classification of OPEN—AWAIT RESPONSE.

For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter. For additional background information about Safety Recommendations A-14-100 through -106, please refer to pages 54 through 63 of our Alaska Department of Public Safety Eurocopter accident report.

This letter addresses NTSB Safety Recommendations A-13 21 and A-14-100 through -106. We issued A-13-21 to the state of New York on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people.

We issued A-14-100 through -106 to the state of New York on November 24, 2014, as a result of our investigation of the March 30, 2013, accident in which a Eurocopter AS350 B3 helicopter, operated by the Alaska Department of Public Safety, impacted terrain while maneuvering during a search-and-rescue flight near Talkeetna, Alaska.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing these recommendations, which were issued more than 4 and 2 years ago, respectively.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement these recommendations; until then, these recommendations will retain their current classification of “Open—Await Response.”

For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter. For additional background information about Safety Recommendations A-14-100 through -106, please refer to pages 54 through 63 of our Alaska Department of Public Safety Eurocopter accident report.

This letter addresses NTSB Safety Recommendations A-13 21 and A-14-100 through -106. We issued A-13-21 to the state of West Virginia on May 15, 2013, as a result of our investigations of three accidents in which airplanes inadvertently collided with meteorological evaluation towers, fatally injuring four people.

We issued A-14-100 through -106 to the state of West Virginia on November 24, 2014, as a result of our investigation of the March 30, 2013, accident in which a Eurocopter AS350 B3 helicopter, operated by the Alaska Department of Public Safety, impacted terrain while maneuvering during a search-and-rescue flight near Talkeetna, Alaska.

We are interested in knowing whether and how our recommendations are implemented, both to ensure that the traveling public is provided the highest level of safety and to identify creative solutions that might be shared with others, and we normally expect actions to address our recommendations to be completed within 3 to 5 years. We have yet to hear from you regarding your progress toward addressing these recommendations, which were issued more than 4 and 2 years ago, respectively.

We would appreciate receiving a response within 90 days indicating any actions you have taken or plan to take to implement these recommendations; until then, these recommendations will retain their current classification of OPEN—AWAIT RESPONSE.

For additional background information about Safety Recommendation A-13-21, please refer to our May 15, 2013, recommendation transmittal letter. For additional background information about Safety Recommendations A-14-100 through -106, please refer to pages 54 through 63 of our Alaska Department of Public Safety Eurocopter accident report.

We were pleased to learn that, on March 1, 2016, you signed Public Act 28 of 2016 into law, regulating METs in Michigan. The law, which became effective May 30, 2016, requires tower owners to register towers that are 50 feet or higher with the Michigan Department of Transportation (MDOT) Office of Aeronautics. Tower locations will be recorded in MDOT’s database of tall structures. The law also requires that METs be painted in equal, alternating bands of orange and white; that they attach at least one orange marker ball to the highest point on each guy wire; and that one or more 7-foot safety sleeves be placed at each anchor point on each guy wire.

Enactment of this law satisfies Safety Recommendation A 13-21, which is classified CLOSED--ACCEPTABLE ACTION.

Thank you for addressing this aviation safety risk.

-From Hilary Vanderstow, Aeronautics Analyst, Michigan Department of Transportation: …[The] requirements are in the signed law that went into effect on May 30, 2016. I have attached the published Public Act 28 of 2016 (House Bill 4727) for your review. More information can also be found on the Michigan Legislature website.

We were pleased to learn that, on August 17, 2015, you published rules in the Oklahoma register to (1) mark anemometer towers (a type of MET) and (2) establish a data base of anemometer tower locations throughout the state of Oklahoma. We note that the new rules went into effect on August 27, 2015. Enactment of these rules satisfies Safety Recommendation A-13-21, which is classified CLOSED—ACCEPTABLE ACTION.

-From Treasure Morgan, Aviation Education and Government Affairs Liaison, Oklahoma Aeronautics Commission: Here is a copy of the MET Tower permanent rules that will be published in the Oklahoma Register on August 17th. The rules will become effective 10 days after publication on August 27, 2015.

We were pleased to learn that, on May 19, 2015, you signed Texas Senate Bill 505, requiring that METs in Texas be marked and painted to make them visible to low-flying aircraft and requiring anyone who owns, operates, or erects an MET to provide notice to, and register it with, the Texas Department of Transportation. We note that the new law will go into effect on September 1, 2015. Enactment of this law satisfies Safety Recommendation A 13-21, which is classified CLOSED—ACCEPTABLE ACTION.

We were pleased to learn that, on December 17, 2014, you approved emergency MET rules that we had recommended and that the Oklahoma Aeronautics Commission (OAC) had adopted on November 13, 2014. We understand that these emergency rules will remain in effect until you approve the permanent rules that the OAC is developing. We are encouraged by your swift and effective action to address the aviation safety risks posed by METs. Pending issuance of the permanent recommended rules, Safety Recommendation A 13 21 is classified OPEN—ACCEPTABLE RESPONSE.

-From Treasure Morgan, Aviation Education and Government Affairs Liaison, Oklahoma Aeronautics Commission: Governor Fallin approved the MET Tower Emergency Rules on December 17 and we received official notification today. I have attached a copy of the Emergency Rules for your convenience – these were the rules approved at the November 13 Commission meeting. I have also attached the official notification that we received today.

Thank you to everyone for your interest, concerns, comments, and a special thanks to those who traveled to OKC to participate in the Public Hearing as well as those who traveled to Tulsa to attend and speak at the November 13 Commission meeting.

The emergency rules adopted by the Oklahoma Aeronautics Commission, once approved, will satisfy Safety Recommendation A-13-21. Accordingly, we urge you to approve these rules.

-From Treasure Morgan, Aviation Education and Government Affairs Liaison, Oklahoma Aeronautics Commission: Attached is a copy of the MET Tower Emergency Rules. The Emergency Rules were adopted at last Thursday’s Commission meeting and were filed on Friday with the Governor’s office, as well as with the House and Senate. The Governor now has up to 45 calendar days to approve or disapprove the submitted Emergency Rules and we will keep you posted.

Thanks to Garret Steggs and Curt Roggow for attending the Commission meeting in Tulsa and for their comments regarding the Emergency Rules during the meeting.

We are encouraged to learn that the Michigan Aeronautics Commission has approved the recommendations proposed by the Michigan Office of Aeronautics, which include collecting information regarding situations specific to Michigan, evaluating the feasibility of revisions, and increasing awareness of the MET voluntary lighting program.

We encourage you to submit future updates regarding your progress in addressing this recommendation electronically at correspondence@ntsb.gov. If a response, including attachments, exceeds 10 megabytes, please e mail us at the same address for instructions. Please do not submit both an electronic copy and a hard copy of the same response. Pending our receipt of such updates and completion of the recommended action, Safety Recommendation A-13-21 remains classified OPEN—ACCEPTABLE RESPONSE.

-From Michael G. Trout, Executive Administrator: Your correspondence of May 15, 2013, addressed to Governor Snyder, (attached) on the National Transportation Safety Board’s (NTSB’s) Safety Recommendation A-13-21 regarding concerns associated with the erection of meteorological evaluation towers (MET) and their impact on the safety of flights was presented to and discussed with the Michigan Aeronautics Commission (Commission) on July 24, 2013. The Commission asked the Michigan Office of Aeronautics (Aero) to further research and report back with recommendations.

On September 11, 2013, NTSB’s recommendation on METs was further discussed with the Commission. Aero recommended the following: • Gather more public input on the topic from aviators, municipalities, representatives of the wind turbine industry, and users of METs to better gauge the situations specific to the state of Michigan. • Review Commission rules to identify the feasibility of revisions based on input from the working group.

• Increase the awareness of the MET voluntary lighting program by hosting public discussions on the topic and working closely with the Michigan Association of Counties, Michigan Township Association, Michigan Association of Planning, and Michigan Agricultural Aviation Association. o Request that information be disseminated to local building and zoning officials to promote the marking of METs as a requirement to their locally issued “special land use permit.” o Provide Information on MDOT’s Office of Aeronautics Web site in a highlighted area promoting the voluntary marking program.

The Commission approved the above recommendations, asking that Aero continue to monitor, evaluate, and report best practices regarding safety alerts on METs. Aero will be gathering information within Michigan, as well as other states throughout the country.

We are encouraged to learn that you recognize the importance of marking and registering METs and that you intend to initiate legislation to require that any MET with a height of 50 feet or more above ground level be marked in accordance with Federal Aviation Administration obstruction-marking guidelines. We urge you not to wait for a federal MET registry to be created, but to register the METs in your state as soon as possible. We look forward to receiving periodic updates regarding your progress in this effort and encourage you to submit these updates electronically at the following e-mail address: correspondence@ntsb.gov.

To avoid confusion, please do not submit both an electronic copy and a hard copy of the same response. In the meantime, pending completion of the recommended action, Safety Recommendation A 13 21 is classified OPEN—ACCEPTABLE RESPONSE.

We are encouraged to learn of your efforts to ensure that METs erected in Iowa are marked in accordance with FAA Advisory Circular 70/7460-1K, but we point out that this recommendation also asks that these METs be registered in a directory. We agree that an FAA national mandate to mark and register METs would be the ideal solution; however, we are not aware of any such plan. In the meantime, we urge you not to wait for a national mandate, but to register the METs in your state. We look forward to receiving periodic updates regarding your progress in this effort and encourage you to submit these updates electronically at the following e mail address: correspondence@ntsb.gov.

To avoid confusion, please do not submit both an electronic copy and a hard copy of the same response. Pending completion of the recommended action, Safety Recommendation A-13-21 is classified OPEN—ACCEPTABLE RESPONSE.

We are encouraged that the Utah Department of Transportation’s Division of Aeronautics, in cooperation with the National Association of State Aviation Officials, member states of the Western Regional Partnership, and local agricultural pilots, is collecting information to determine the most appropriate course of action to address this safety concern. Pending our receipt of periodic updates regarding your progress, and completion of the recommended action, Safety Recommendation A-13-21 is classified OPEN—ACCEPTABLE RESPONSE.

We are encouraged to learn that MDOT’s Office of Aeronautics plans to seek an official recommendation from the Michigan Aeronautics Commission to enact the recommended legislation and that, as a temporary measure, MDOT is currently asking that METs be marked voluntarily. We look forward to receiving periodic updates regarding your progress in addressing this recommendation. In the meantime, pending completion of the recommended action, Safety Recommendation A-13-21 is classified OPEN—ACCEPTABLE RESPONSE.

We are encouraged to learn of your efforts to review this safety issue and possible solutions with aviation stakeholders, and we look forward to receiving periodic updates regarding your progress. We encourage you to submit these updates electronically at the following e-mail address: correspondence@ntsb.gov. To avoid confusion, please do not submit both an electronic copy and a hard copy of the same response. Pending completion of the recommended action, Safety Recommendation A-13-21 is classified OPEN—ACCEPTABLE RESPONSE.

We are encouraged to learn that you recognize the importance of marking and registering METs and that your Transportation Cabinet will explore ways to address this safety issue once the Kentucky General Assembly is back in session. Pending our receipt of periodic updates regarding your progress and completion of the recommended action, Safety Recommendation A 13-21 is classified OPEN—ACCEPTABLE RESPONSE.

Thank you for your prompt response to this safety issue.

We are encouraged by the state of Washington’s work with constituents and stakeholders to enact legislation to address this recommendation and look forward to receiving periodic updates regarding your progress. Pending completion of the recommended action, Safety Recommendation A-13-21 is classified OPEN—ACCEPTABLE RESPONSE.

We are encouraged to learn that the Maryland Aviation Administration plans to review options for marking and lighting METs and registering them in a common public-access database, and that you have been working with other states to develop a national solution to the issue. We look forward to receiving periodic updates regarding your progress in addressing this recommendation. In the meantime, pending completion of the recommended action, Safety Recommendation A-13-21 is classified OPEN—ACCEPTABLE RESPONSE.

-From Paul Trobino III, Director, Iowa Department of Transportation: Thank you for your May 15 letter to Governor Branstad recommending Iowa enact legislation requiring that meteorological evaluation towers (MET) are marked and registered in a directory. As director of the Iowa Depa1tment ofTransp01tation (DOT), Governor Branstad has asked that I respond to your letter. We share your safety concerns with METs which is why we began taking actions several years ago to address these concerns.

In 2010, the Iowa DOT became aware of the issues surrounding METs from the Iowa Agricultural Aviation Association. The Iowa DOT worked with the Federal Aviation Administration (FAA) Central Region Office in Kansas City, along with many other states and aerial applicator interests to encourage FAA action on the issue to mitigate aviation hazards.

In June of2011, the FAA issued a set of voluntary guidelines for marking of MET towers (FAA Advisory Circular 70/7460-1K) and issued a policy letter supporting the use of those guidelines. The FAA stopped short of pursuing mandatory compliance marking MET towers.

The Iowa DOT was very supportive of FAA issuing voluntary guidelines; however, we provided comments at that time urging a comprehensive national solution and recommending FAA to make marking guidelines mandatory. Since the guidelines were issued in 2011, the Iowa DOT has observed several MET towers around Iowa that have been constructed using the voluntary marking guidelines. Firms designing the renewable wind energy facilities have reported that marking of MET towers is now standard practice.

Following the recent NTSB recommendation to make the markings mandatory, the Iowa DOT put a request out to the Iowa Agricultural Aviation Association, asking aerial applicators from around Iowa to report known locations of any unmarked MET towers in Iowa. Only one known unmarked MET tower was reported . The Office of Aviation at this time is working to determine the owner of that tower so they can be contacted and supplied with the FAA's marking guidance.

While several states have passed legislation requiring the use of FAA marking guidelines, the Iowa DOT continues to believe a national solution is the best approach. Until a national solution is in place, the actions we have taken at the Iowa DOT in partnership with aviation interests shall be sufficient to address this issue in Iowa. We do not believe additional state legislation is necessary.

-From James T. Smith, Jr., Secretary, Maryland Department of Transportation: Thank you for your letter to Governor Martin O'Malley regarding safety recommendation for meteorological evaluation towers (MET). The Governor received your letter and asked me to respond to you on his behalf.

Having a uniform, nationwide registry of MET facilities is an ideal solution. We agree the Federal Aviation Administration (FAA) should require marking and registration of all METs. A central registry would be more standardized and valuable to pilots than the current system of 50 or more separate registries with many formats/standards for registration. The State of Maryland will continue to work with other states to encourage development of a national solution. Separately, the Maryland Department of Transportation through the Maryland Aviation Administration (MAA) will review options to mark and light MET facilities and register each to a common public-access database.

The Governor appreciates hearing from you and, on his behalf, I also thank you for the interest in this issue. If you need further assistance, please do not hesitate to contact Mr. Ashish J. Solanki, A.A.E., Director, Office of Regional Aviation Assistance.

-From Steven D. Hatter, Deputy Commissioner, Department of Transportation and Public Facilities, State of Alaska: We are in receipt of your letter to Governor Parnell recommending the State of Alaska enact legislation requiring Meteorological Evaluation Towers be marked and registered in a directory.

The Alaska Department of Transportation and Public Facilities (ADOT&PF) reviewed the NTSB' s recommendation and we see this safety concern as a piece of a bigger issue here in Alaska. The demand for communication towers and wind turbines has grown significantly in rural Alaska and not all towers are being marked, lighted, charted, or registered. Alaska Air carriers have expressed concern over these tall structures being potential safety hazards and are asking the ADOT &PF for assistance.

ADOT &PF' s Division Statewide Aviation is reaching out to aviation stakeholders such as the Alaska Air Carriers Association, FAA Industry Council, and Alaska Aviation Coordination Council to review the NTSB safety recommendation and provide comments to the FAA. We need to determine how best to manage the various airspace safety concerns in a comprehensive manor. It may be necessary for the FAA to develop marking standards that are more appropriate to today's environment.

We appreciate the NTSB 's safety recommendation and will use it to further our discussion as we work toward a solution to the larger safety concern here in Alaska.

-From Carlos M. Braceras, P.E., Executive Director, State of Utah, Department of Transportation: The Governor's Office has asked me to review and respond to your letter dated May 15, 2013 containing Safety Recommendation A-13-21, to enact legislation requiring that meteorological evaluation towers (MET) be marked and registered in a directory. Utah enjoys a vibrant and supportive partnership with the aviation community. Aviation is an important tooLfor continued economic growth and development in Utah. We are committed to ensuring the safety of aviation while, at the same time, developing and growing other aspects of our economy.

We appreciate the seriousness of the recommendations provided by the National Transportation Safety Board and are taking those recommendations under advisement. The Utah Department of Transportation's Division of Aeronautics is working with the National Association of State Aviation Officials (NASAO), member states of the Western Regional Partnership, and local agriculture pilots. The information being collected, including a review of legislation already enacted by other states, will assist in determining the most appropriate course of action for Utah.

I appreciate the efforts of the NTSB and its mission of advocating and promoting safety recommendations.

-From Neil Abercrombie, Governor, State of Hawaii: We share the National Transportation Safety Board (NTSB) safety concerns and concur with NTSB Safety Recommendation A-13-21 regarding marking and registration of Meteorological Evaluation Towers (MET). As we turn increasingly to renewable energy sources, it is critical that we do so responsibly without compromising safety. Unmarked towers, especially at unknown locations, are an unacceptable hazard to civil and military aviation safety in the State of Hawaii. Especially vulnerable are critical search and rescue, firefighting, and law enforcement helicopter operations.

We intend to initiate legislation to require any MET with a height of 50 feet or more above ground level be marked in accordance with FAA obstruction marking guidelines. Once a federal MET registry is created, we would also require all METs be entered into that registry.

-From Tristan K. Atkins, WSDOT Director of Aviation: Gov. Jay Inslee's office has asked me to respond to your letter dated May 15,2013, regarding the National Transportation Safety Board's (NTSB) recommendation that Washington state enact legislation requiring that meteorological evaluation towers (MET) are marked and registered in a directory.

Efforts to enact similar legislation are being led by members of our state legislature. Legislators are working with constituents and stakeholders to redraft an unsuccessful2013 legislative session bill (Senate Bill 5000), which was crafted to address the marking of towers. The Washington State Department ofTransportation is actively providing technical assistance to legislators and a diverse group of aviation stakeholders, including the Aircraft Owners and Pilots Association (AOP A) and the Washington Pilots Association (WP A), that are working to build a coalition in support of MET tower legislation for the 2014 session.

I intend to share your letter with appropriate legislators and interested aviation groups.

-From Kirk T. Steudle, Director: Michigan Governor Rick Snyder asked me to respond to your May 15, 2013, correspondence on the National Transportation Safety Board’s Safety Recommendation A-13-21 regarding concerns associated with the erection of meteorological evaluation towers (MET) and their impact on the safety of flights.

Michigan does not currently have regulations in place to require markings or registration of proposed METs outside of close proximity to airports. The Michigan Department of Transportation’s (MDOT’s) Office of Aeronautics has reviewed this situation and is currently asking for voluntary markings on these towers when they receive notification of their existence.

Given what has been learned in previous discussions with the Federal Aviation Administration and other states, and in light of the recommendations contained in A-13-21, MDOT’s Office of Aeronautics will be making a presentation to the Michigan Aeronautics Commission on July 24, 2013, seeking an official recommendation regarding possible legislative action in accordance with A-13-21. MDOT’s Office of Aeronautics will provide an electronic update after July 24, 2013, and as necessary.

If you have any questions, please feel free to contact either me or Mike Trout, Executive Administrator, Office of Aeronautics.

-From Michael W. Hancock, P.E., Secretary: Your letter to Governor Beshear was forwarded to the Kentucky Transportation Cabinet for response regarding referenced number .A-13-21.

We certainly recognize the importance of mitigating risk in low altitude aviation operations by requiring a meteorological evaluation tower ("MET") to be marked and registered. Please be advised that our General .Assembly is not in session until J anuary, 2014. The Cabinet will explore future opportunities at that time to enhance safety issues related to METs and aviation.

We appreciate your letter regarding this subject. Please feel free to contact us at any time.