What happened
On 28 February 1999, a DHC-8-311, registration G-BRYP, was performing a scheduled public transport flight from Bristol to Plymouth City Airport. The flight was operated by a crew of four and carried nine passengers. During the approach to Runway 31, the crew encountered moderate turbulence and significant wind gusts, with surface winds reported at 230 degrees at 16 knots, gusting up to 26 knots.
As the aircraft approached the threshold, the first officer was acting as the handling pilot. The crew had transitioned from autopilot to manual flight control at 1,000 feet to better manage the wind conditions. During the flare, the aircraft experienced a sudden increase in the rate of descent. Upon touchdown, the landing was heavy, causing the left main landing gear to collapse. The aircraft subsequently struck the runway with its right gear and nose gear, and the left wing tip made contact with the ground. The impact caused extensive damage to the left-hand propeller blades, the aft fuselage, and the landing gear structure. Following the impact, an acrid smell and smoke were noted in the cabin, prompting the cabin crew to initiate an emergency evacuation.
The investigation
The AAIB investigation utilized high-quality cockpit voice and flight data recorder information to reconstruct the final moments of the flight. The data revealed that while the aircraft was tracking the centerline, it was subjected to significant vertical acceleration changes, indicating windshear. The investigation focused on the mechanical failure of the landing gear, specifically the shearing of the 'fuse' pin in the hinge joint. Metallurgical analysis determined that the fracture was caused by mechanical overload rather than fatigue. This failure was triggered when the left outboard wheel's tyre was distorted by the impact, transmitting a high instantaneous compressive load through the gear leg. The investigation also reviewed company procedures regarding wind limits for first officers and the decision-making process of the commander during the approach.