2 weeks Ago By Rytis Beresnevičius
The National Transportation Safety Board (NTSB) has issued safety recommendations to Boeing and the Federal Aviation Administration (FAA) as it continues its investigation into a gear-up landing and the subsequent evacuation of a FedEx Boeing 757 in October 2023. Non-conforming evacuation door latch The NTSB stated that its preliminary findings from the investigation into the incident indicated different reasons why a jumpseat occupant initially failed to open both forward doors and deploy the emergency slides. A post-accident examination of the right-hand door, which the occupant was eventually able to open, had a non-conforming R1 bannis latch, which releases the slide pack when an armed door is opened.
According to the investigators, the bannis latch is supposed to have three links with two spacers and hardware, as mandated by an FAA airworthiness directive (AD) that came into effect in May 1986, which referenced Boeing Service Bulletin (SB) 757-25A0058, issued on April 18, 1986. “Instead, the R1 bannis latch on the accident airplane had only one link and lacked other required hardware [..
.], which caused the slide pack to jam before the jumpseat occupant was eventually able to force the door to open.” Meanwhile, the investigators concluded that the left-hand side front door, while it had the airworthy bannis latch, had an incorrectly routed deployment strap that prevented the door from opening.
FedEx, EATL, and United Airlines have expressed their concerns about the directive for the Boeing 757. Non-conforming part installed after the 1986 directive Following the October 2023 gear-up landing, FedEx inspected 97 other 757 aircraft in its fleet, finding that none had incorrectly routed deployment straps. However, 46 doors, or about 24%, had bannis latches that were non-compliant with the aforementioned 1986 AD.
The bannis latches were also non-conforming according to another directive, which the FAA issued for Boeing 727, 737 (737-100 through 737-800), 757-200, and 757-300 aircraft in July 2001. The directive referenced the 1986 Boeing SB and another bulletin that the plane maker issued in May 2000 (on different dates for different aircraft types). According to the NTSB, while FedEx does not currently have 727 or 737 aircraft, it has 85 757-200 converted freighters ( ch-aviation data).
Following the US-based cargo carrier’s inspections, Boeing issued a multi-operator message (MOM) on April 8, 2024. In response, a non-US operator informed the plane maker that three of the four 757 doors it had inspected had non-conforming bannis latches. Boeing built the 757-200 that was involved in the gear-up landing in 1988, two years after it issued the SB addressing the bannis latches.
According to ch-aviation data, Boeing delivered the 757-200, registered as N977FD, to Air Europe, a now-defunct United Kingdom-based airline, in 1988. Subsequent operators include Air Europa (the Spain-based airline that was part of the same group as Air Europe), Transavia, China Southern Airlines, Royal Aviation, Transmeridian Airlines, SBA Airlines, and finally, FedEx, which took delivery of the aircraft in 2013. “FedEx records indicate that the bannis latch was inspected on January 12, 2023.
The work card indicated to check the cables for fraying. At that time, there should have been a chain in the latch assembly and not a cable. Although the R1 door was eventually opened despite the incorrectly configured latch, the NTSB is concerned that it hindered an emergency evacuation.
” During the investigation, NTSB reviewed 757 and FedEx’s aircraft maintenance manuals (AMM) and the Boeing Illustrated Parts Catalog (IPC). The documents contained inconsistent depictions of the bannis latch, including images of non-conforming latches that should have been replaced following the 1986 directive. “These inconsistent, conflicting depictions would likely be confusing to maintenance personnel and could lead to the installation of and failure to detect nonconforming latches, which could result in another incident of an evacuation slide not deploying properly when needed.
” Following the NTSB’s discoveries, Boeing told the investigators that it should update the AMM and IPC in May. The airline has been reducing the number of its planes as part of a larger fleet downsizing plan. Mandating replacements As such, following FedEx’s inspections of its 757 fleet, the NTSB concluded that non-conforming bannis latches could be present on other 757, as well as 727 and 737 aircraft, which could result in “delayed evacuation during an emergency should the slide become jammed.
” The investigators recommended that once Boeing updates the AMM and IPC, the plane maker should issue an SB for operators to inspect and, if necessary, modify or replace bannis latches on 727, 737, and 757 aircraft. The NTSB also recommended that the FAA mandate airlines to complete the required actions to ensure that the bannis latches on their aforementioned Boeing aircraft comply with the two airworthiness directives. “The NTSB also concludes that ensuring operators’ maintenance documentation contains consistent, accurate depictions of the correct configuration of the bannis latch assembly would help prevent the use of non-compliant components that could lead to delayed evacuation during an emergency should the slide become jammed.
” Boeing and operators should review their maintenance manuals and IPCs to ensure that the depicted bannis latches are in the correct and airworthy configuration. The gear-up landing that prompted the recommendations happened at Chattanooga Metropolitan Airport (CHA) on October 4, 2023. While the accident resulted in no injuries to the three people who were onboard the aircraft, including two pilots and the one jumpseat occupant, the aircraft was written off and scrapped, according to planespotters.
net . The aircraft sustained damage after its main landing gear failed to extend on approach..
