After a BA 787 suffered a nose gear collapse last month, the British AAIB issued a Special Bulletin, to keep it from happening again.
We discussed this incident when it happened last month. British Airways maintenance crews were working on a Boeing 787, while other crews loaded it with cargo. At the time, the company was using the aircraft (tail number G-ZBJB) for cargo-only flights. So on this occasion, crews were preparing the jet for such a cargo flight to Frankfurt, Germany.
In the immediate aftermath of the incident, there was no official announcement regarding its cause. However, at the time we theorized that the issue could relate to the placement of a pin, in the nose gear leg. Now, the AAIB has issued a Special Bulletin relating to the 787 gear collapse, that seems to confirm these theories.
The AAIB 787 gear collapse SB also reveals that contrary to what we previously wrote, there was one injury from this incident. The five people onboard were fine. However, there was one person operating a cargo loader, near the front of the aircraft. This individual received minor injuries.
Damage and Sequence of Events
As for the aircraft, it suffered damage to the nose of the fuselage and the nose gear doors. Also, both engine cowlings touched the pavement, suffering damage. And finally, door 2L (left side, second from the front) was ripped off the fuselage, as it jammed between the airstairs and the dropping plane (see below).
So, how did this happen? As the AAIB explains, the gear collapse happened as the 787 crew performed a Dispatch Deviation Guide (DDG) procedure. This relates to something called an Acceptable Deferred Defect. Typically, this would come after the crew gets a warning/fault, which they can still fly with, under specific conditions.
The DDG procedure to resolve the fault required the crew to cycle the landing gear selection lever on the ground. Among other steps, they had to insert special pins to all gear legs, to stop them from retracting. The crews inserted the pins in the main landing gear downlocks correctly. However, the same wasn’t true for the nose gear. The AAIB describes that crews inserted the pin in the wrong pin hole, causing the gear collapse of the 787.
AAIB – Previous 787 Gear Collapse Incidents
This has happened before – hence our theorizing, in the previous article. Because of a similar issue in 2018, Boeing issued a Service Bulletin in March 2019. This provides instruction for the installation of an insert in the inner bore of the other pin hole. The aim is to make it impossible to insert the downlock pin in that hole (apex pin inner bore). After a revision, the FAA incorporated this SB into an Airworthiness Directive (AD) in January 2020.
However the British Airways 787 suffering this gear collapse did not incorporate this AD, as the AAIB Special Bulletin notes. That is because this FAA AD had a 36-month compliance time, starting from the 16th of January 2020. However, British Airways had circulated a Technical News leaflet, illustrating the right AND wrong ways of installing this pin.
But after this nose gear collapse, the AAIB notes that British Airways recirculated this leaflet to its 787 maintenance crews. Also, the airline will expedite the incorporation of the relevant FAA AD, to its 787 fleet.
As of this writing, the affected 787 still appears to be out of service. The AAIB is continuing its investigation.
For the AAIB Special Bulletin, go HERE