Skip Ribbon Commands
Skip to main content
Safety Recommendation Details

Safety Recommendation A-15-028
Synopsis: 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.
Recommendation: TO THE COMMERCIAL SPACEFLIGHT FEDERATION: Work with the Federal Aviation Administration to develop and issue human factors guidance for operators to use throughout the design and operation of a crewed vehicle. The guidance should address, but not be limited to, the human factors issues identified during the SpaceShipTwo accident investigation.
Original recommendation transmittal letter: PDF
Overall Status: Open - Acceptable Response
Mode: Aviation
Location: Koehn Dry Lake, CA, United States
Is Reiterated: No
Is Hazmat: No
Accident #: DCA15MA019
Accident Reports: In-Flight Breakup During Test Flight Scaled Composites SpaceShipTwo, N339SS Near Koehn Dry Lake, California October 31, 2014
Report #: AAR-15-02
Accident Date: 10/31/2014
Issue Date: 8/4/2015
Date Closed:
Addressee(s) and Addressee Status: Commercial Spaceflight Federation (Open - Acceptable Response)

Safety Recommendation History
From: NTSB
To: Commercial Spaceflight Federation
Date: 2/16/2017
Response: We note that you intend to work with the FAA to develop and issue supplemental human factors guidance for operators to use throughout the design and operation of a crewed vehicle. We point out, however, that existing human factors guidance for new systems was developed for civilian and military aviation and for government aerospace industries, not for the commercial space flight industry, and because the commercial space flight industry is relatively new, no such guidance exists that is specific to it. We believe that such guidance could help ensure that human factors issues are fully addressed during a commercial space vehicle’s design, and also during its operation, by acknowledging human factors limitations in written guidance and simulator training. Pending the development of human factors guidance that addresses the concerns discussed above, Safety Recommendation A-15-28 is classified OPEN--ACCEPTABLE RESPONSE.

From: Commercial Spaceflight Federation
Date: 10/20/2016
Response: -From Eric Stallmer, President: The Commercial Spaceflight Federation (CSF) was provided two recommendations from the National Transportation Safety Board (NTSB) following their investigation into the Scaled Composites SpaceShipTwo accident. Our responses can be found on the following page. We would also like to extend our willingness to participate in and assist with future investigations that may arise. We hope that the NTSB feels comfortable reaching out to us for assistance and expertise from the very earliest stages of future investigations so that we may optimize our contributions. The Commercial Spaceflight Federation would like to thank the NTSB for the substantial amount of time and effort NTSB dedicated to this investigation. We appreciate the NTSB’s professionalism and patience, as well as its efforts to complete the investigation within nine months. CSF and the NTSB share the common goal of developing a safe and flourishing commercial space industry and appreciate the effort put forth towards achieving that goal. The CSF will work with the FAA to develop and issue supplemental human factors guidance in addition to those presently in use throughout the design and operation of crewed vehicles, including human factor issues like those identified in the SpaceShipTwo accident investigation. Documentation and knowledge sharing are both integral in developing human factors guidance for commercial space transportation operators.

From: NTSB
To: Commercial Spaceflight Federation
Date: 7/8/2016
Response: When we issued these recommendations to you, we asked that you respond within 90 days detailing the actions you had taken or intended to take to implement them. However, in the year since they were issued, we have not received this information. We are interested in knowing whether and how you have implemented our recommendations, both to ensure the public the highest level of safety and to identify creative solutions that can be shared with others. Accordingly, we would appreciate a prompt reply detailing your progress in addressing these recommendations. Pending your timely response, Safety Recommendations A 15 27 and 28 remain classified OPEN—AWAIT RESPONSE. The background and basis for Safety Recommendation A-15-27 can be found in Section, “Analysis of Emergency Response,” on pages 17 through 20 of our report on the October 31, 2014, SpaceShipTwo accident. Similarly, the background and basis for Safety Recommendation A-15-28 can be found in Section, “Analysis of Scaled Composites’ Consideration of Human Factors in SpaceShipTwo’s Design and Operation,” on pages 45 through 47 of the report. A copy of the report is available on our website at