Accident Details
On a day visual flight rules flight, a Metro III aircraft, registration C-FIPW and serial number AC524, operated by Northern Dene Airways Ltd. as Norcanair Flight KA1051, departed Stony Rapids, Saskatchewan, with two crew members and nine passengers. The flight was destined for La Ronge, Saskatchewan.
Sequence of Events
Upon arrival at La Ronge at approximately 1410 central standard time, the crew completed the approach and landing checklists and confirmed the gear-down indication. The aircraft was landed on Runway 18 in a crosswind, touching down firmly approximately 1000 feet from the threshold. During the landing, the left wing dropped, causing the propeller to contact the runway. The aircraft veered to the left despite full rudder and aileron deflection. The crew applied maximum right braking and shut down both engines. The aircraft departed the runway and traveled approximately 200 feet through the infield before the nose and right main gear were torn rearward; the left gear collapsed into the wheel well. The aircraft slid on its belly and came to rest approximately 300 feet off the side of the runway.
Injuries and Damage
Three passengers sustained minor injuries from the sudden stop associated with the final collapsing of the landing gear. The other passengers and the pilots were not injured.
Probable Cause
The investigation identified three findings as to causes and contributing factors: (1) An incorrect roller of a smaller diameter and type was installed on the left main landing gear outboard bellcrank assembly, contrary to company and industry practice. (2) The smaller diameter roller reduced the required rigging tolerances for the bellcrank-to-cam assembly in the down-and-locked position and allowed the roller to eventually move beyond the cam cutout position, resulting in the collapse of the left landing gear. (3) A rigging check was not carried out after the replacement of the bellcrank roller. Such a check should have revealed that neither the inboard nor outboard bellcrank assembly met the minimum rigging requirements for proper engagement with the positioning cam.