Accident
On 22 March 2021 at 1505 UTC, a Tecnam P2008-JC aircraft, registration G-TSFC, experienced a collapse of the right main landing gear while taxiing after a normal landing at Stapleford Aerodrome, Essex. The flight was a training sortie with two crew members on board and no passengers. Neither crew member was injured. The right main landing gear sustained damage due to the collapse.
Investigation
Examination of the aircraft revealed that the bolt securing the inboard end of the right main landing gear leg had failed in fatigue. The fracture surfaces showed fatigue cracking, and wear marks on the bolt indicated that it had been moving within its bushings. The source of the fatigue crack was most likely the wear and damage to the bolt's surface protection.
The aircraft was manufactured in 2015 and was powered by a single Rotax 912-S2 piston engine. The pilot held a Commercial Pilot's Licence and had 481 hours of total flying experience, with 6 hours on type.
Maintenance Context
Prior to the accident, the aircraft had been maintained under a Light Aircraft Maintenance Programme (LAMP), which was a generic schedule for light aircraft and did not specifically require detailed inspection of the main landing gear attachment bolts. Shortly before the incident, the operator transitioned the aircraft to the manufacturer's specified maintenance schedule. This schedule includes an annual or every-100-hour inspection of nose and main gear attachments, bolts, and bushings for condition, security, cracks, corrosion, and damaged surface protection.
The operator's maintenance organisation also stated that it would check the torque of the bolts every 50 hours and intends to replace them every 200 to 300 hours. These measures aim to detect degradation before failure occurs.