On June 18th, we reported on a British Airways 787 suffering a nose gear collapse while on stand
at London Heathrow Airport. In mid-July, the UK’s Air Accidents Investigation Branch (AAIB)
issued a special bulletin regarding the accident,
giving us additional insight into how this accident happened.
The 787-8 registered G-ZBJB was being loaded with cargo in preparation for a flight to Frankfurt
on June 18th. While being prepared for its journey, crews were performing a
quote-unquote “Dispatch Deviation Guide” (DDG) procedure. This is a procedure that permits the
operation of an aircraft, under specific conditions, with particular instruments
or functions inoperative for a period of time- until rectification can be made.
In this case, the AAIB states that the DDG procedure required the cockpit landing
gear selection lever to be cycled with hydraulic power applied to the aircraft.
It was at this time that human error caused the accident, with the AAIB stating the following:
“To prevent the landing gear from retracting, the procedure required pins to be inserted in the nose
and main landing gear downlocks. However, the nose landing gear downlock pin was installed in
the nose landing gear downlock apex pin bore which was adjacent to the correct location to install
the downlock pin. When the landing gear selector was cycled the nose landing gear retracted.”
The language is certainly on the more technical side. But if we were to sum it
up in layman’s terms, a critical locking pin was inserted into the wrong hole.
With the pin absent from the necessary location, the nose landing gear retracted
once the landing gear selector was cycled. With all this in mind, we can see that the
nose gear didn’t actually collapse. In reality, it was retracted as it
was meant to, given the cockpit commands. Interestingly, it appears that this is not
the first time an incident of this nature has occurred. The AAIB states that in 2018,
another Boeing 787 experienced a retraction of the nose landing gear while the aircraft was on
the ground. The cause was found to be an incorrect insertion of the nose landing gear downlock pin.
As a result of this previous event, Boeing published a service bulletin instructing
operators to quote “install an insert into the nose landing gear lock link apex pin inner bore.”
Doing so would prevent the nose landing gear downlock pin from being inserted into the apex pin
bore instead of the adjacent downlock pin hole. This procedure was mandated by an FAA
Airworthiness Directive (AD) published on January 16th, 2020. However, it looks like
authorities considered this to be less than urgent, providing a compliance time of 36
months from the publication date. In the case of G-ZBJB, an insert had not been installed.
In the end, the sudden collapse resulted in damage to the aircraft’s lower forward
fuselage and engine cowlings. The aircraft passenger cabin door was also separated as
it struck mobile steps on the way down, causing a cargo loader to be injured.
For its part, British Airways had issued a “Technical News leaflet” on April 9th, 2020,
showing the correct and incorrect position of the nose landing gear downlock pin.
Referencing the FAA Airworthiness Directive and the Special Bulletin,
it was also re-issued on December 9th, 2020.
As a result of this accident, the airline re-issued the technical news leaflet the
day after the June 18th incident. The AAIB states that BA is now planning to
quote-unquote “expedite the incorporation” of the airworthiness directive to install the insert.
Was the FAA’s 36-month compliance window too long? Did BA do enough by issuing two
technical news leaflets? Can the design be changed and/or an insert be installed by
Boeing during manufacturing to firmly prevent this confusion in the future? Or was it simply
down to one person making a critical mistake? There are a lot of questions from this incident,
with a lot to think about. Let us know what you think by leaving a comment!