Overview
On a scheduled air service from Belfast City Airport to Doncaster Sheffield Airport, aircraft G-GAVA experienced a landing gear failure after touchdown, resulting in a runway excursion. The flight, operated by a crew of two pilots with one passenger, had an uneventful departure, cruise, and approach. The aircraft landed on Runway 20 at 1836 hrs following radar vectors for a visual final approach.
Sequence of Events
The aircraft touched down with an indicated airspeed of 102 kt and a peak normal acceleration of 1.3 g. The commander moved the power levers to ground idle and then to reverse. As the aircraft decelerated, the commander returned the power levers to ground idle and instructed the co-pilot to move the RPM levers to taxi. At 65 kt, eight seconds after touchdown, the left wing dropped suddenly, and the aircraft began to yaw left. The commander was unable to maintain directional control using rudder or nosewheel steering. The aircraft departed the left side of the runway, turning approximately 90°, and stopped on the grass. The left landing gear had collapsed, and the aircraft came to rest on its baggage pannier, right landing gear, and left wing.
The commander shut down both engines and switched the Electrics Master switch to emergency off. The co-pilot communicated with ATC, who dispatched emergency services. The co-pilot evacuated the aircraft via the left side main exit, which released but could not fully open due to the sill being at ground level; all occupants evacuated without injury. Emergency services arrived at 1838 hrs, by which time the occupants were clear.
Probable Cause
The aircraft’s left main landing gear failed as a result of stress corrosion cracking in the forward pintle housing, at the top of the left landing gear cylinder. The landing gear material is known to be susceptible to stress corrosion cracking. A design solution implemented by the aircraft manufacturer following a 2012 accident, intended to prevent this cracking, had not met its original design intent.