What happened
On 20 May 2020, a Skyleader 600 aircraft, registration ZU-TAM, departed Eagles Creek Airfield for Krugersdorp Airfield (FAKR) to undergo a scheduled annual inspection. Shortly after takeoff, the pilot heard an unusual noise from the undercarriage. Following the retraction of the landing gear, the green indicator lights extinguished, signaling that the gear was no longer down. The pilot attempted to deploy the gear using the cockpit's emergency manual handles, but the mechanism failed to respond.
Due to COVID-19 lockdown restrictions, the pilot sought assistance from the maintenance professional scheduled for the inspection at FAKR. After a fly-past confirmed that the nose gear was down while the main gear remained partially extended, the pilot proceeded with a landing on Runway 08. Upon touchdown, the main and nose landing gears collapsed entirely, causing the aircraft to skid along the runway. There were no injuries to the two occupants, though the aircraft sustained substantial damage to the lower fuselage, tyre rims, and internal components.
The investigation
SACAA AIID investigators examined the aircraft's mechanical state and maintenance history. The inspection of the wheels and tyres revealed scratch and chafe marks, confirming that the gear was not fully extended at the moment of impact. The investigation focused on the landing gear actuator and linkages, noting that while the electric motor and wiring were functional, the right-side main landing gear was unserviceable.
Findings
- The primary cause of the gear collapse was a disconnected pushrod caused by an unsecured bolt within the right-side main landing gear wheel well.
- The pilot's attempt to use the emergency extension system was unsuccessful because the disconnected pushrod physically prevented the mechanism from operating.
- A review of maintenance records showed that a mandatory service bulletin (SB 01/2018), which addressed the security of the landing gear control system, had not been implemented.
- The aircraft was operating under a special flight permit that restricted the flight to essential crew only; however, a non-essential passenger was on board.