Lost in Translation: Misrigged Main Landing Gear

The French BEA-D (Le Bureau Enquêtes Accidents Défense – Air (UPDATE: renamed the BEA d’État [BEA-É] in 2018 in recognition of its role in all state aircraft) has issued the final report into their investigation of a landing gear collapse on Canadair CL-415 F-ZBEU of the Securité Civile at Ajaccio-Napoleon Bonaparte Airport, Corsica on 1 August 2016.

The Occurrence

The fire bomber, callsign ‘Pélican 42’, was one of two aircraft taxying for take-off when the right hand Main Landing Gear (MLG) collapsed as the aircraft turned to align with runway 20 for take off.

Securité Civile Canadair CL-415 F-ZBEU MLG Collapse at Ajaccio, 1 August 2016 (Credit: BEA-D)

Securité Civile Canadair CL-415 F-ZBEU MLG Collapse at Ajaccio, 1 August 2016 (Credit: BEA-D)

In particular the right hand float was damaged, and a fuel leak occurred.

Damage to Securité Civile Canadair CL-415 F-ZBEU (Credit: BEA-D)

Damage to Securité Civile Canadair CL-415 F-ZBEU (Credit: BEA-D)

Safety Investigation

The MLG is locked by a strut by the principle of a geometric locking by overextension.  When examined the MLG strut was found to be outside the allowable range which led to premature wear of the components of the strut assembly.

pelican 42 c

The recommended value for X in the Component Maintenance Manual (CMM):

Dimension X must be equal to dimension Y or up to a maximum of 0.055 inch (1.40 mm) less than dimension Y.

The investigation revealed that the maintenance organisation overhauling the landing gear struts had translated the CMM from English to French but had made an error with this dimension:

pelican 42 dThe landing gear was jolted unlocked when the aircraft taxied onto the runway at a higher than intended speed (c 14 knots rather than 6 knots).

Safety Resources

Aerossurance has previously published:


Aerossurance is pleased to sponsor the 9th European Society of Air Safety Investigators (ESASI) Regional Seminar in Riga, Latvia 23 and 24 May 2018.

Aerossurance is pleased to be both sponsoring and presenting at a Royal Aeronautical Society (RAeSHuman Factors Group: Engineering seminar Maintenance Error: Are we learning? to be held on 9 May 2019 at Cranfield University.

raes are we learning

Aerossurance has extensive air safety, operations, airworthiness, human factors, aviation regulation and safety analysis experience.  For practical aviation advice you can trust, contact us at: enquiries@aerossurance.com