History of Flight
On Sunday, 2 April 2023, a pilot and four passengers flew a Cessna 310Q (registration ZS-III) from Upington Aerodrome (FAUP) to Rand Aerodrome (FAGM). The flight was conducted under visual meteorological conditions at night, in accordance with Part 91 of the Civil Aviation Regulations. The pilot held a Commercial Pilot Licence with 1,600 total flying hours, including 22.9 hours on type. The aircraft departed FAUP at approximately 1730Z after refueling with 409 litres of Avgas 100LL, bringing total fuel to 540 litres.
During the final approach for Runway 35 at FAGM, the pilot selected the landing gear down and observed three green lights indicating all gears were down and locked. During the landing roll, the left wing dropped, and the left propeller and wing struck the ground. The aircraft veered left and came to rest 60 metres from the runway edge. The aircraft sustained substantial damage; no injuries were reported.
Investigation Findings
The investigation determined that the left main landing gear collapsed because it unlocked from the down position due to an overload failure of the bell-crank axis mechanism. This collapse also damaged the push-pull tube and the bell-crank’s adjusting screw.
Probable Cause
The left main landing gear collapse resulted from an overload failure of the locking mechanism, caused either by the pre-load developed during the adjustment process or by an oscillatory motion from an incorrect adjustment (looseness) that, due to the mechanism's geometry, amplified stress on the bell-crank.
Contributory Factors
A contributory factor was an incorrect rigging adjustment performed during maintenance.
Aircraft and Operational Details
The aircraft was a Cessna C310Q operated by Fundiflex Aviation as a private Part 91 flight. The accident site was on Runway 35 at FAGM, near the intersection with Runway 29, at coordinates 26°14'32.04"S, 28°9'1.87"E, elevation 5,483 feet. Meteorological conditions at the time included wind from 340° at 7 knots, temperature 19°C, and dew point 12°C.