What happened
On 21 November 2012, a Falcon 402, registration ZU-MDI, was performing a private flight from Lanseria Aerodrome to Wonderboom Aerodrome. The purpose of the flight was to transport an authorized individual to perform an annual inspection on the aircraft. During the landing circuit at Wonderboom, the pilot observed a red warning light, indicating that the right-hand undercarriage was not properly locked in the down position.
In an attempt to rectify the issue, the pilot executed emergency gear extension maneuvers over a general flying area in Pretoria. Despite these efforts, the gear failed to secure. The pilot subsequently notified the tower and proceeded to land at the slowest possible airspeed using full flaps. Upon touchdown on runway 29, the aircraft veered toward the right side of the runway, causing the right-hand undercarriage to collapse. All zero fatalities and zero injuries were reported, as the pilot and two passengers evacuated the aircraft safely after it came to a halt.
The investigation
SACAA AIID investigators examined the wreckage and the mechanical components of the landing gear. The investigation focused on why the gear failed to lock despite the pilot's attempts at manual extension. Metallurgical analysis was performed on a rod end component recovered from the aircraft to determine the nature of the failure.
Findings
- The primary cause of the landing gear failure was a failure of the rod end caused by previously undetected damage.
- This mechanical failure prevented the down-lock mechanism in the starboard main undercarriage from securing properly when the gear lever was moved to the down position.
- Meteorological conditions at the time of the accident were clear with good visibility (CAVOK) and were not a contributing factor.
- The aircraft, which was a rebuilt airframe, had been maintained according to regulations, and the annual inspection records were in order.