NTSB · Safety Recommendation
Safety Recommendation A-15-020
Recommendation
TO THE FEDERAL AVIATION ADMINISTRATION: Implement steps in your evaluation of experimental permit applications to ensure that applicants have (1) identified single flight crew tasks that, if performed incorrectly or at the wrong time, could result in a catastrophic hazard, (2) assessed the reasonableness, including human factor considerations, of the proposed mitigations to prevent errors that could result from performing those tasks, and (3) fully documented the rationale used to justify related assumptions in the hazard analysis required by 14 Code of Federal Regulations 437.55.
Safety Issue and Context
On October 31, 2014, at 1007:32 Pacific daylight time, the SpaceShipTwo (SS2) reusable suborbital rocket, N339SS, operated by Scaled Composites LLC (Scaled), broke up into multiple pieces during a rocket-powered test flight and impacted terrain over a 5-mile area near Koehn Dry Lake, California. The pilot received serious injuries, and the copilot received fatal injuries. SS2 was destroyed, and no one on the ground was injured as a result of the falling debris. SS2 had been released from its launch vehicle, WhiteKnightTwo (WK2), N348MS, about 13 seconds before the structural breakup. Scaled was operating SS2 under an experimental permit issued by
the Federal Aviation Administration’s (FAA) Office of Commercial Space Transportation (AST) according to the provisions of 14 Code of Federal Regulations (CFR) Part 437.
Response History
July 21, 2025 · NTSB Correspondence · FAA
We previously informed the FAA that section 450.109, which states that applicants must identify reasonably foreseeable hazards, including those resulting from human factors, is responsive to the second part of this recommendation. We also said section 450.115, which states that applicants must submit a description of the flight safety analysis methodology that identifies all assumptions and their justifications, is responsive to the third part of this recommendation. However, we requested that the FAA send us the section in the regulations that states applicants must identify single flight crew tasks that, if performed incorrectly or at the wrong time, could result in a catastrophic hazard.
In response to our question, the FAA stated that Parts 450 and 460 interdependently address hazards and risks to public safety and require applicants to identify hazards that would jeopardize public safety and implement mitigations for any hazards identified with an unacceptable level of risk. The FAA also reported that AC 460.15-1, which was developed in response to Safety Recommendation A-15-19, contains guidance on single-point failures. We believe the guidance in AC 460.15-1 is responsive to the first part of this recommendation and will be useful to prospective applicants when applying for a commercial space authorization.
We believe the FAA’s actions thus far to update the regulations and guidance mentioned above are positive and a necessary step to satisfying the intent of this recommendation. However, because this recommendation specifies improving the FAA’s process for evaluating experimental applications—and the revised regulations and guidance are intended for applicants—we would like to know if similar updates have been made to the FAA’s evaluation process to verify that applicants have addressed the three parts of this recommendation. Pending our receipt of this information, the Board has voted to keep Safety Recommendation A-15-20 classified OPEN-- ACCEPTABLE RESPONSE.
August 27, 2024 · Recipient Response · FAA
-From Michael G. Whitaker, Administrator: The Board’s response letter dated February 23, 2024, requested the section of 14 CFR part 450, Launch and Reentry License Requirements, that states applicants must identify single flight crew tasks that, if performed incorrectly or at the wrong time, could result in a catastrophic hazard. The FAA regulations under 14 CFR parts 450 and 460, Human Space Flight Requirements, interdependently address hazards and risks to public safety. The regulations require the applicant to identify hazards jeopardizing public safety, and for those hazards with unacceptable levels of risk to be mitigated through design or operational requirements.
For example, a single flight crew task, if performed incorrectly, could lead to a catastrophic event for the flight crew itself, so long as public safety criteria are met. As part of our response to NTSB safety recommendation A-15-19, the FAA is developing a new part 460 human factors AC that will include guidance consistent with this recommendation. The FAA anticipates the new AC to now be published by September 30, 2024.
February 23, 2024 · NTSB Correspondence · FAA
We note that you no longer intend to revise Part 437 because you believe this recommendation is already addressed in Part 450, Streamlined Launch and Reentry Licensing Requirements, which was published on December 10, 2020.
We believe section 450.109, which states that applicants must identify reasonably foreseeable hazards, including those resulting from human factors, addresses the second part of this recommendation. In addition, section 450.115, which states that applicants must submit a description of the flight safety analysis methodology that identifies all assumptions and their justifications, satisfies the third part of this recommendation. However, we did not find any language in Part 450 that responds to the first part of this recommendation.
Therefore, we request that you send us the section of Part 450 that states that applicants must identify single flight crew tasks that, if performed incorrectly or at the wrong time, could result in a catastrophic hazard. Pending our receipt and review of this additional information, Safety Recommendation A-15-20 remains classified OPEN-- ACCEPTABLE RESPONSE.
July 10, 2023 · Recipient Response · FAA
-From Polly Trottenberg, Acting Administrator: As part of the lessons learned from the 2014 accident, the FAA included these recommendations as part of the hazard analysis for piloted systems in 14 CFR 450.109(b)(1), Flight Hazard Analysis, and published guidance to industry in FAA Advisory Circular (AC) 450.109-1, Flight Hazard Analysis, dated August 5, 2021. Additionally, the FAA continues to develop guidance for industry to provide an acceptable means of compliance (AMOC) with the human factors requirements in 14 CFR 460.15, Human Factors.
Due to the FAA’s higher priority release of guidance material to accompany the 14 CFR Part 450 Streamlined Launch and Reentry Licensing Requirements Final Rule (85 FR79566) issued on December 10, 2020, the new anticipated timeframe for issuing the AMOC human factors guidance is by December 31, 2023.
Currently, the FAA has no applicants seeking a Part 437 experimental permit. Experimental permits are not actively being sought by the commercial space transportation (CST) industry because the permits do not allow for compensation or hire and are not eligible for government indemnification. Additionally, the new streamlined regulations in Part 450, Streamlined Launch and Reentry Licensing Requirements, are flexible enough to authorize the launch or reentry of experimental reusable suborbital rockets while also allowing applicants to go through a single authorization process as their program grows from testing to flight. For these reasons, the FAA does not intend to update Part 437.
The FAA is continuing its work with and support of the ASTM International’s Committee F47 on Commercial Spaceflight (F47). ASTM F47 has updated the technical subcommittees and has multiple subcommittees working on developing standards pertaining to aspects of human safety, including considerations for design, qualifications screening, training, ground operations and maintenance, occupant protection, and risk assessment, to ensure emphasis is placed on the human systems in human spaceflight.
It applies to owners, operators, manufacturers, technicians, contractors, and supply chain organizations involved in the development and maintenance of human-rated spaceflight vehicles, habitats, and related spaceflight activities. Additional information on F47 is available at the following website:
https://www.astm.org/get-involved/technical-committees/committee-f47
November 15, 2022 · NTSB Correspondence · FAA
We note that you are still working with the Commercial Space Transportations Advisory Committee (COMSTAC) to identify appropriate methods for addressing hazards caused by human error. We also note that you anticipate publishing, in calendar year 2023, guidance that will include an acceptable means of compliance with the human factors requirements in section 460.15, Human Factors. In addition, we note that you are working with COMSTAC and the American Society for Testing and Materials (ASTM) to form a new commercial spaceflight committee that will develop voluntary consensus safety standards for the design, manufacturing, and operational use of vehicles used for spaceflight.
We believe the work you described, and your planned actions, are responsive to these recommendations. Pending revisions to Part 437 that address the hazard analysis requirements in section 437.55, Safety Recommendation A-15-20 remains classified OPEN--ACCEPTABLE RESPONSE.
March 7, 2022 · Recipient Response · FAA
-From Steve Dickson, Administrator: The Federal Aviation Administration (FAA) continues to address these recommendations in a coordinated effort through ongoing industry engagement, rulemaking activities, and support of voluntary consensus standards. We plan to propose updates to the experimental permit regulations in Title 14, (CFR) Part 437, focusing on requirements in § 437.55, Hazard Analysis. The FAA continues to work with the Commercial Space Transportation Advisory Committee (COMSTAC) to provide the FAA with industry’s views on appropriate methods to address hazards caused by human error.
The FAA continues to develop guidance for industry to provide an acceptable means of compliance with the human factors requirements in 14 CFR § 460.15, Human Factors. Due to the higher priority release of guidance material to accompany the 14 CFR Part 450 Streamlined Launch and Reentry Licensing Requirements Final Rule (85 FR 79566) on December 10, 2020, the anticipated timeframe for issuing this guidance is Calendar Year 2023.
In collaboration with COMSTAC, the American Society for Testing and Materials (ASTM) formed a new Commercial Spaceflight committee to develop human spaceflight safety standards. The areas to address include, but are not limited to, the design, manufacturing, and operational use of vehicles used for spaceflight. The FAA has been involved with the committee’s formation from the beginning and will continue to support industry efforts to develop voluntary consensus standards. Although the ASTM International Committee F47 on Commercial Spaceflight has not yet begun a standards effort on human factors, it is within the committee’s charter if the industry deems it necessary.
For more information on this committee, visit: https://www.astm.org/get-involved/technical-committees/committee-f47
July 16, 2021 · NTSB Correspondence · FAA
We note that the FAA is developing guidance that will include an acceptable means of compliance with the human factors requirements in section 460.15, Human Factors. We also note that you continue to work on your rulemaking project to revise 14 CFR Part 437, “Experimental Permits,” with updates to the hazard analysis requirements in section 437.55, and other commercial space transportation regulations.
Pending completion of the human factors guidance for operators, Safety Recommendation A-15-19 remains classified “Open—Acceptable Response.” Pending revisions to Part 437 that address the hazard analysis requirements in section 437.55, Safety Recommendation A-15-20 remains classified OPEN-- ACCEPTABLE RESPONSE.
November 20, 2020 · Recipient Response · FAA
-From Steve Dickson, Administrator: As noted in our previous response, the Federal Aviation Administration (FAA) is actively addressing these recommendations through our ongoing industry engagement, rulemaking activities, and support of voluntary consensus standards.
From June 2017 to February 2018, the FAA actively engaged the commercial space industry to discuss challenges of the FAA’s current regulatory structure and to address potential near- and long-term changes to FAA regulations. Since February 2018, the FAA has been engaged in a high-priority rulemaking to combine and streamline launch and reentry licensing requirements, which have delayed the part 437 rulemaking and other efforts. On September 30, 2020, the Administrator signed the Streamlined Launch and Reentry Requirements (SLR2) Final Rule; publication in the Federal Register is pending.
The FAA still plans to propose updates to its experimental permit regulations, part 437, with particular focus on its hazard analysis requirements (§ 437.55, Hazard Analysis), as well as updating its other commercial space transportation regulations. To inform this effort, the FAA will work with the Commercial Space Transportation Advisory Committee (COMSTAC) to provide the FAA with industry’s views on appropriate methods to address hazards caused by human error. In addition, COMSTAC will provide the FAA with a proposed prioritization list to modernize the rest the commercial space regulations.
The FAA has completed its assessment of current part 460, Human Space Flight Requirements, and determined that no new rulemaking is needed at this time. However, the FAA is developing guidance for the industry that will provide an acceptable means of compliance with the human factors requirements in § 460.15, Human Factors. The FAA anticipates issuing this guidance by December 31, 2021.
In addition, the American Society for Testing and Materials (ASTM International) formed Committee F47 on Commercial Spaceflight in November 2016. The scope of this committee includes:
The development and maintenance of voluntary consensus standards and recommended practices for the commercial spaceflight industry. Areas to address in standards include, but are not limited to, design, manufacturing and operational use of vehicles used for spaceflight. The committee shall also develop human spaceflight safety standards.
The FAA has been an active committee partner from the beginning and will continue to support industry efforts to develop voluntary consensus standards. Although the ASTM International committee has not yet begun a standards effort on human factors, it is within the committee’s charter to do so if the industry deems it necessary. More information on the committee can be found at the following website:
February 10, 2017 · NTSB Correspondence · FAA
We note that you are collaborating with CSF and the Commercial Space Transportation Advisory Committee (COMSTAC) Standards Working Group to develop consensus standards, and that, as part of this work, CSF issued a contract to ASTM International. We further note that you continue to work on your rulemaking project to revise Title 14 CFR Part 437, “Experimental Permits,” particularly focusing on the hazard analysis requirements in section 437.55. In addition, you are currently evaluating the need to revise the regulations addressing human factors contained in Title 14 CFR Part 460.
We were pleased to note that Congress appropriated funds in your fiscal year 2016 budget to develop and implement a research and development program for commercial space transportation, and that the new program will include a project for developing human factors best practices.
Pending completion of the human factors guidance for operators, Safety Recommendation A-15-19 remains classified “Open—Acceptable Response.” Pending revisions to Part 437 that address the hazard analysis requirements in section 437.55, and revisions to Part 460 addressing human factors, Safety Recommendation A-15-20 remains classified OPEN—ACCEPTABLE RESPONSE.
December 6, 2016 · Recipient Response · FAA
-From Michael P. Huerta, Administrator: The Federal Aviation Administration (FAA) is actively addressing these recommendations in a coordinated fashion through our ongoing industry engagement and rulemaking activities. ln collaboration with the Commercial Spaceflight Federation (CSF) and the Commercial Space Transportation Advisory Committee (COMST AC) Standards Working Group, the FAA is supp01ting the development of consensus standards and is encouraged by the progress to date. CSF has informed us that they issued a contract with the American Society for Testing and Materials to assist with standards development and the FAA intends to fully support these activities.
We believe there is also a strong role for voluntary consensus standards as an acceptable means of compliance to FAA regulations.
With regard to the regulations, as previously noted, the FAA is engaged in an active rulemaking project for Title 14, Code of Federal Regulations (14 CFR) Part 437, Experimental Permits, with particular focus on its hazard analysis requirements (§ 437.55). In addition, the FAA is currently assessing the need for new rulemaking to address the human factor regulations contained in 14 CFR Part 460. The review is ongoing, but at a minimum we expect to provide improved guidance material to industry.
For the first time in Fiscal Year (FY) 20 16, Congress appropriated dedicated funding to develop and implement an applied Commercial Space Transportation Research, Engineering, and Development (RE&O) portfolio, providing $1 million for these efforts. The new portfolio will include a project that will support the development of standards and new regulatory guidance by identifying the best practice considerations associated with crew human factors for small, winged commercial space flight vehicles. The FAA is currently finalizing the details of this new project and plans to issue a research task in the coming months.
January 11, 2016 · NTSB Correspondence · FAA
We note that you have an active rulemaking project to rewrite the experimental permit regulations in Part 437 because of difficulties in applying the first generation rule, particularly in the hazard analysis requirements. We further note that you are initiating a review of the human factors regulations in Part 460. We support these actions to satisfy Safety Recommendation A 15-20. Pending their completion, the recommendation is classified OPEN—ACCEPTABLE RESPONSE.
October 30, 2015 · Recipient Response · FAA
-From Michael P. Huerta, Administrator: The FAA is examining our response to this recommendation with an emphasis on our public safety-related regulations and guidance. We have an active rulemaking project to rewrite our experimental permit regulations in Title 14, Code of Federal Regulations (14 CFR) Part 437, due to difficulties in application of the first generation rule, particularly in the hazard analysis requirements. We also are initiating a review of our human factors regulations in 14 CFR Part 460, as well as its related guidance. Our expectation is that, at a minimum, our guidance will be updated and improved.
The part 460 regulations may also be updated if we determine this is necessary. All of these regulatory efforts will address the three elements identified in this recommendation.
In addition to our regulatory efforts, the FAA's Fiscal Year (FY) 2016 President's Budget Request proposes to establish a CST safety research budget line. If Congress funds this important research portfolio, the FAA intends to launch a research and development project focused on identifying best practice considerations for crew human factors for small winged commercial space flight vehicles. This research project will be instrumental in informing the development of consensus standards and improved regulations and guidance.