What happened
At approximately 11:54 EDT, a Piper PA31, registered C-GRVW, was performing a visual flight rules flight from a private grass strip to Cochrane, Ontario, before proceeding to Moosonee. The aircraft, operated by Wabusk Air, was carrying a pilot and a passenger. After completing an approach to Runway 32, the pilot confirmed the landing gear was down and locked, a status also verified by the passenger.
Following a normal touchdown, the pilot retracted the flaps and turned off the boost pumps. As the pilot prepared to apply brakes to taxi toward taxiway Bravo, the gear warning horn activated. Immediately following this, the right main landing gear collapsed, which triggered the subsequent collapse of the left main and nose landing gear. The aircraft stopped roughly 1,550 feet from the runway threshold, positioned just off the right side of the runway. There were no injuries resulting from the incident.
The investigation
Investigators examined the aircraft and the runway, noting propeller strike marks that indicated the right main gear failed first. The aircraft sustained damage to the nose gear doors, the fuselage underside, and the right wing tip. While the right engine propeller blades were bent around the nacelle, the left engine blades were found in the feathered position.
Upon inspecting the landing gear, investigators found no mechanical failures or rigging discrepancies. The oleo extension appeared normal, and the gear could be manually locked into the down position using a hand pump. However, investigators discovered that snow had packed into the gear bays while the aircraft was being moved to the apron.
Findings
- The investigation determined that the landing gear handle inadvertently moved to the 'UP' position during the landing roll, initiating the retraction sequence.
- A broken spring in the landing gear handle allowed the lever to move past the neutral stop with minimal effort.
- It is believed the handle was likely positioned in a way that bypassed the anti-retraction system during the approach.
- Due to the ease with which the handle could be bumped, the movement occurred before the aircraft achieved 'weight on wheels' status, leading to the gear collapse during deceleration.