NTSB · Safety Recommendation
Safety Recommendation A-14-119
Recommendation
TO THE FEDERAL AVIATION ADMINISTRATION: Provide your certification engineers with written guidance and training to ensure that (1) assumptions, data sources, and analytical techniques are fully identified and justified in applicants’ safety assessments for designs incorporating new technology and (2) an appropriate level of conservatism is included in the analysis or design, consistent with the intent of Advisory Circular 25.1309 (Arsenal draft).
Safety Issue and Context
On January 7, 2013, about 1021 eastern standard time, smoke was discovered by cleaning personnel in the aft cabin of a Japan Airlines (JAL) Boeing 787-8, JA829J, which was parked at a gate at General Edward Lawrence Logan International Airport (BOS), Boston, Massachusetts. About the same time, a maintenance manager in the cockpit observed that the auxiliary power unit (APU) had automatically shut down. Shortly afterward, a mechanic opened the aft electronic equipment bay and found heavy smoke coming from the lid of the APU battery case and a fire with two distinct flames at the electrical connector on the front of the case.
None of the 183 passengers and 11 crewmembers were aboard the airplane at the time, and none of the maintenance or cleaning personnel aboard the airplane was injured. Aircraft rescue and firefighting personnel responded, and one firefighter received minor injuries. The airplane had arrived from Narita International Airport, Narita, Japan, as a regularly scheduled passenger flight operated as JAL flight 008 and conducted under the provisions of 14 Code of Federal Regulations (CFR) Part 129.
Response History
December 2, 2025 · NTSB Correspondence · FAA
We note that AC 25.1309-1B contains the recommended guidance for certification engineers. We are also aware that, in 2020, the FAA revised its system safety class for FAA engineers and recurrent training for designated engineering representatives to include the system safety aspects cited in this recommendation, a discussion of the 2013 787 battery fire event, and materials related to the justification of critical assumptions in safety assessments. We believe these actions satisfy the intent of this recommendation. Consequently, the Board has voted to classify Safety Recommendation A-14-119 CLOSED—ACCEPTABLE ACTION.
January 10, 2025 · Recipient Response · FAA
-From Michael G. Whitaker, Administrator: The FAA published the System Safety Assessments (SSA) Final Rule in the Federal Register on August 27, 2024 (89 FR 68706). This rule addresses the risk from latent failures, including control systems jams and the risk of wear-related failures, by modifying § 25.671, General, and § 25.1309, Equipment, Systems, and Installations. Additionally, the FAA has issued three new Advisory Circulars (ACs) and amended two existing ACs to provide guidance material for acceptable means, but not the only means, of showing compliance with the regulations in this final rule. These ACs are available in the public docket for this rulemaking:
• AC 25.671–1, Control Systems – General. • AC 25.901–1, Safety Assessment of Powerplant Installations. • AC 25.933–1, Unwanted In-Flight Thrust Reversal of Turbojet Thrust Reversers. • AC 25.629–1C, Aeroelastic Stability Substantiation of Transport Category Airplanes. • AC 25.1309–1B, System Design and Analysis.
The final rule addresses these recommendations by revising § 25.671(c)