On 18th June, we witnessed the collapse of NLG (nose landing gear) of an 8 years old British Airways Boeing B787-8 (G-ZBJB) aircraft while parked on a gate. Is this event a first timer ? What kind of repairs are expected ?
✔Ofcourse , the Dreamliner NLG collapse is not for the first time ! On 4th March 2016, an Ethiopian Airlines Boeing 787-8 (ET-ASH) collapsed at Addis Ababa Intl. airport boarding gate.
✔The root cause of the NLG collapse was determined as an attempt to retract the NLG on the ground (Weight on wheels – WOW condition) after incorrect installation of the NLG downlock pin in the apex pin inner bore of the NLG lock link assembly.
✔FAA had issued an Airworthiness directive (AD 2019-23-07) , that required installing an insert to prevent installation of the pin in the apex pin inner bore (incorrect location).
✔United Airlines requested FAA issue an AMOC (Alternative Method of Compliance) to allow the apex pin inner bore to be completely filled with sealant, but was turned down by the regulator.
✔Though , the root cause of the current BA NLG collapse is yet to be determined, the repairs will take months of time to bring back the aircraft to service.
✔Not going into details, in the absence of a complete damage report, if we analyse the impact & probable damages, recovery may require multiple NDT inspections and controlled replacement of the
👉Fwd. fuselage lower shell ,
👉Internal structures (Few repairs as well) ,
👉Possibly the fittings and surrounding structure at NLG attach points apart from the NLG itself.
Author – Tanmay Palei
Sr. Aircraft Structure Engineer
