The attached letter from the NTSB Chair provides information about the Collision with Powerlines and Terrain during Forced Landing MARPAT Aviation Bell Helicopter UH-1B, N98F Amherstdale, West Virginia June 22, 2022. The details of this accident investigation and the resulting safety recommendations may be found in the attached report, which can also be accessed at http://www.ntsb.gov.
The NTSB is vitally interested in these recommendations because they are designed to prevent accidents and save lives. We would appreciate a response within 90 days of the date of this letter detailing the actions you have taken or intend to take to implement these recommendations. When replying, please refer to the safety recommendations by number (for example, A-24-20 through -25). We encourage you to submit your response to ExecutiveSecretariat@ntsb.gov. If your reply exceeds 20 megabytes, including attachments, please e mail us at the same address for instructions on how to send larger documents. Please do not submit both an electronic copy and a hard copy of the same response.
This letter provides information about the National Transportation Safety Board’s (NTSB) August 14, 2024, report Collision with Powerlines and Terrain during Forced Landing MARPAT Aviation Bell Helicopter UH-1B, N98F (NTSB/AIR-24-04). The details of this accident investigation and the resulting safety recommendations may be found in the attached report, which can also be accessed at http://www.ntsb.gov.
As a result of this investigation, we identified the following safety issues:
• the need to review all experimental exhibition airworthiness certificates issued to turbine-powered rotorcraft.
• the need for periodic reviews for experimental exhibition airworthiness certificates.
• the need for recurrent inspections of aircraft equipped with Ozark Aeroworks T53-series engines.
• the need for operators of experimental exhibition aircraft to submit a list all events at which the aircraft will be exhibited.
• the need for a method to ensure that operators of experimental exhibition aircraft meet their annual obligation to submit program letters.
• the need for inspector guidance that requires routine surveillance of operators of aircraft with experimental exhibition airworthiness certificates.
Accordingly, the NTSB makes the following safety recommendations to the Federal Aviation Administration (FAA). Additional information regarding these recommendations can be found in the noted sections of the report.
• Review all experimental exhibition airworthiness certificates issued to turbine-powered rotorcraft and ensure that their operating limitations meet the standards of the latest iteration of Federal Aviation Administration Order 8130.2, Airworthiness Certification of Aircraft. (A 24 20) (See section 2.4.)
• Establish periodic reviews for experimental exhibition airworthiness certificates to ensure that those aircraft are being inspected and maintained according to the latest iteration of Federal Aviation Administration Order 8130.2, Airworthiness Certification of Aircraft. (A-24-21) (See section 2.4.)
• Require operators of aircraft equipped with Ozark Aeroworks T53-series engines to perform recurrent inspections of the rear bearing cover and the exhaust diffuser inner cone and inner struts with the exhaust diffuser cover removed. (A-24-22)
(See section 2.5.)
• Remind operators of experimental exhibition aircraft about the requirement to submit, to the appropriate flight standards district office, program letters that list all events at which the aircraft will be exhibited. (A-24-23) (See section 2.6)
• Develop a method for ensuring that operators of experimental exhibition aircraft meet their annual obligation to submit program letters; such a method could include potential penalties for operators that do not meet this obligation. (A 24-24) (See section 2.6)
• Revise Federal Aviation Administration Order 8900.1, Flight Standards Information Management System, to include inspector guidance requiring routine surveillance of operators of aircraft with experimental exhibition airworthiness certificates. (A 24 25) (See section 2.6)
In addition, the NTSB reiterates the following recommendation to the FAA:
Develop national safety standards, or equivalent regulations, for revenue passenger-carrying operations that are currently conducted under Title 14 Code of Federal Regulations Part 91, including, but not limited to, sightseeing flights conducted in a hot air balloon, intentional parachute jump flights, and living history flight experience and other vintage aircraft flights. These standards, or equivalent regulations, should include, at a minimum for each operation type, requirements for initial and recurrent training and maintenance and management policies and procedures. (A-21-9)
The NTSB is vitally interested in these recommendations because they are designed to prevent accidents and save lives. We would appreciate a response within 90 days of the date of this letter, detailing the actions you have taken or intend to take to implement these recommendations. When replying, please refer to the safety recommendations by number (Safety Recommendations A-24-20 through -25 and reiterated Safety Recommendation A-21-9.) We encourage you to submit your response to ExecutiveSecretariat@ntsb.gov. If your reply, including attachments, exceeds 20 megabytes, please e mail us at the same address for instructions on how to send larger documents.
Please do not submit both an electronic copy and a hard copy of the same response.
Aviation Investigation Report AIR-24-04 Collision with Powerlines and Terrain during Forced Landing MARPAT Aviation Bell Helicopter UH-1B, N98F Amherstdale, West Virginia June 22, 2022 report published on August 27, 2024:
Federal Aviation Administration Inspection and Maintenance Standards
The FAA issued Order 8130.2G in August 2010 to provide inspectors with updated standards for the airworthiness certification of aircraft. Version G of the order stated that turbine-powered rotorcraft operated under an experimental exhibition airworthiness certificate were to be inspected under an FAA approved program that met the requirements of 14 CFR 91.409(f). The Memorandum of Deviation to chapter 4, section 10 of Order 8130G, which became effective in December 2011, then allowed such rotorcraft to be inspected according to the requirements of 14 CFR Part 43 Appendix D.
The inspection standards in Part 43 Appendix D did not have sufficient scope and depth for inspecting former military turbine-powered rotorcraft, especially given the complex design of typical former military rotorcraft. The NTSB’s review of these standards found that they were generic inspection criteria for aircraft systems and components undergoing annual and 100-hour inspections. These criteria did not comprise an appropriate inspection program for former military turbine-powered rotorcraft; such a program would be expected to have more comprehensive information than only a listing of inspection criteria.
For example, Appendix D stated that a reciprocating aircraft engine needed to be inspected for proper cylinder compression but did not specify critical turbine engine components for inspection, such as an engine compressor or turbine, and the necessary inspection steps to ensure the continued airworthiness for a complex turbine powered aircraft.
Further, Appendix D stated that flight and engine controls were to be inspected for “improper installation and improper operation” and that all systems were to be inspected for “improper installation, poor general condition, apparent and obvious defects, and insecurity of attachment.” However, Appendix D did not discuss the steps needed to properly assess the condition of flight and engine controls and system components. The NTSB concludes that the FAA erred when it allowed, via its 2011 Memora