NTSB · Safety Recommendation
Safety Recommendation A-25-008
Recommendation
TO BOEING: Issue a service bulletin advising operators of Boeing 727 and 737 airplanes that use the same bannis latch design as Boeing 757 airplanes (757 200, 200CB, and -300 series) to inspect those airplanes and, if necessary, modify or replace the bannis latches with the correct configuration.
Safety Issue and Context
On October 4, 2023, about 2347 eastern daylight time, the flight crew of FedEx flight 1376, a Boeing 757-236, received an engine indication and crew alerting system message indicating a failure of the left hydraulic system shortly after takeoff from Chattanooga Metropolitan Airport-Lovell Field (CHA), Chattanooga, Tennessee. The flight crew turned the airplane back to CHA but was unable to lower the landing gear. After multiple attempts to extend the gear were unsuccessful, the crew declared an emergency and performed an emergency gear up landing.
After the airplane came to a complete stop, the flight crew performed the evacuation checklist in the Quick Reference Handbook, and a jumpseat occupant onboard the airplane attempted to open the left (L1) door. The door rotated halfway open but would not open fully, and the slide did not deploy.
Response History
June 27, 2025 · Recipient Response · Boeing Company
-From Stella Weidner, Director, Product Safety, Boeing: After reviewing the AMM and IPC for the 727, 737 and 757, it was found Boeing does not use the 757 door 1 and 2 bannis latch assembly and spacer links configuration on the 727 or 737 models, or on door 4 of the 757. The bannis latch design which uses spacer links, as in the reference event, is unique to the 757 doors 1 and 2 only. Due to the uniqueness of the bannis latch and spacer link configuration on the 757 doors 1 and 2, there is no need to issue service bulletins for 727 or 737 models. The 757 door 3 is a bottom hinged door and has a different escape slide deployment method that does not utilize the bannis latch assembly.
See attachment A for bannis latch figures.
April 3, 2025 · NTSB Correspondence · Boeing Company
The NTSB is an independent federal agency charged by Congress with investigating every civil aviation accident in the United States and significant events in the other modes of transportation—railroad, transit, highway, marine, pipeline, and commercial space. We determine the probable causes of the accidents and events we investigate and issue safety recommendations aimed at preventing future occurrences. In addition, we conduct transportation safety research studies and offer information and other assistance to family members and survivors for each accident or event we investigate.
We also serve as the appellate authority for enforcement actions involving aviation and mariner certificates issued by the Federal Aviation Administration (FAA) and US Coast Guard, and we adjudicate appeals of civil penalty actions taken by the FAA.
We are providing the following information to urge Boeing to act on the safety recommendations in this letter because we believe your organization can help reduce the risk of future accidents.
This letter also includes information about our March 27, 2025, report, Address Noncompliant Evacuation Slide Components on Boeing Airplanes. 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:
• Unairworthy bannis latches that don’t comply with Airworthiness Directives 86-09-09 and 2001-15-01 may be installed on other in-service Boeing 757-200, -200CB, and -300 series airplanes, which could lead to delayed evacuation during an emergency should the slide become jammed. • Because the same bannis latch design used on certain Boeing 757 airplanes (757-200, -200CB, and -300 series) is also used on Boeing 727 and 737 airplanes, these airplane models could also have bannis latches installed that are not the correct configuration.
• Ensuring operators’ maintenance documentation contains consistent, accurate depictions of the correct configuration of the bannis latch assembly would help prevent the use of noncompliant components that could lead to delayed evacuation during an emergency should the slide become jammed.
Accordingly, the NTSB makes the following safety recommendations to Boeing.