Summary
On an unspecified date, a Wabusk Air Piper PA31 (registration C-GRVW, serial number 31-618) was involved in an accident at Moosonee Airport, Ontario. The aircraft departed a private grass strip with a pilot and passenger to pick up another passenger at Cochrane Airport. After departing Cochrane, the pilot flew to Moosonee and conducted a visual flight rules approach for Runway 32.
Accident Sequence
Approximately 1.5 nautical miles from the runway, the pilot selected the landing gear down and confirmed a down-and-locked indication. The passenger, another company pilot seated in the right seat, verbally confirmed the indication. The aircraft landed normally. After touchdown, the pilot selected flaps up and boost pumps off. As the pilot was about to apply brakes for taxiway Bravo, the gear warning horn sounded, and the right main landing gear collapsed, followed quickly by the left main and nose landing gear. The aircraft came to rest approximately 1550 feet from the threshold of Runway 32, just off the right side of the runway. No injuries occurred.
Examination Findings
The accident occurred at about 1154 eastern daylight time in visual meteorological conditions. The pilot held a commercial pilot licence with an expired category 1 medical certificate and was exercising private pilot privileges. As of April 2007, he had approximately 4000 total flying hours, most on type, and held a multi-engine rating but was not instrument-rated.
When investigators arrived, the aircraft had been moved to the apron. Runway propeller strike marks indicated the right main gear collapsed first. The flaps and landing gear were in the retracted position. Damage included the underside of the right wing tip, fuselage underside, and nose gear doors. The right engine propeller blades were bent back around the nacelle and were not feathered; left engine blades were similarly bent but feathered.
The landing gear handle was in the down neutral position. When the aircraft was lifted and snow cleared from the gear bays, the landing gear free-fell to the down position and locked using the hand pump. No mechanical failure or rigging discrepancies were found in the landing gear components. The landing gear oleo extension appeared normal.
Probable Cause
No faults were found indicating mechanical failure or improper rigging. Due to a broken spring in the landing gear handle, which allowed easy movement past the neutral stop, the handle was likely inadvertently positioned above the locking solenoid before weight on wheels was achieved. During the landing roll, the handle was bumped up far enough to begin the retraction sequence, bypassing the anti-retraction system. The landing gear handle inadvertently moved to an "UP" selection, activating the gear warning horn and retracting the landing gear.