What happened
On the morning of 15 December 2021, a Cessna 310Q, registration ZS-BRO, departed Rand Aerodrome (FAGM) in Gauteng for a routine training flight. The aircraft, operated under Part 1s41 regulations, was occupied by a flight instructor and a student pilot. The flight was intended to visit the Johannesburg South General Flying area before returning to Rand Aerodrome.
During the return approach to Runway 35, the crew confirmed the landing gear was down and locked. While the instructor initially described the landing as normal, the aircraft's left side began to sink during the landing roll. The left propeller blades struck the runway surface, and the aircraft veered left, eventually with the left wing tip touching the grass. The aircraft came to a stop approximately 45 metres from the runway edge. There were no injuries to the occupants, though the aircraft sustained substantial damage.
The investigation
SACAA AIID examined the wreckage and the aircraft's maintenance history. Physical inspection of the left main landing gear revealed that the gear had nearly retracted into the wheel well. Investigators found that the left landing gear bell crank lower lug and the trunnion upper clevis had fractured.
Microscopic analysis of the fractured surfaces showed no evidence of fatigue, suggesting the components failed due to a single-event overload. While the aircraft's logs showed no recorded hard landings, investigators noted that the propeller strike marks and the aircraft's position off the centerline suggested instability during the landing phase. Maintenance records indicated the aircraft had undergone an annual inspection only 100 hours prior to the accident, and there were no outstanding service bulletins or known defects regarding the landing gear system.
Findings
- The left main landing gear collapsed because the upper trunnion clevis and the bell crank lower lug broke.
- The failure was caused by a single overload event during landing.
- It is likely that the aircraft was unstable during its approach, leading to a hard landing on the left main gear.
- The impact caused the left propeller tips and the left wing tip to contact the runway and ground.