What happened
On the afternoon of 23 April 2023, a pilot operating a Rockwell Commander 112TCA, registration ZS-KJU, was conducting a private flight from Wonderboom Aerodrome (FAWB) to Hartbeespoort Dam. The flight, conducted under Part 91 regulations, proceeded normally until the return leg to FAWB. During the pre-landing checks, the pilot observed that while the right main gear indicated down and locked, both the left main gear and the nose gear indicated an unsafe position.
Despite activating the emergency gear extension handle, the nose gear indication remained unsafe. Although air traffic control visually confirmed all three gears appeared down during a low-level fly-past, the nose landing gear collapsed during the landing roll on Runway 29. The aircraft skidded approximately 80 meters, with the propeller contacting the runway surface, resulting in substantial damage to the airframe. The pilot escaped the aircraft unassisted and was not injured.
The investigation
SACAA AIID investigators examined the aircraft's maintenance history and the landing gear hydraulic system. The investigation revealed that a mandatory periodic inspection (MPI) had been left incomplete due to corrosion discovered on the forward wing spars in June 2022. Consequently, the aircraft's Certificate of Airworthiness had expired on 31 July 2022.
Technical examination of the landing gear power pack at Rand Aerodrome uncovered a disconnected electrical carbon brush and a spring destroyed by excessive heat. Additionally, evidence of hydraulic fluid weeping into the electrical components was found, which likely contributed to the power pack failure. While the investigators could not definitively determine why the nose gear failed to reach the over-centre position following the emergency extension, the physical evidence pointed to internal component degradation.
Findings
- The pilot was properly licensed and medically fit for the flight.
- The nose gear leg failed to lock in the down position, leading to its collapse during touchdown.
- The aircraft was not airworthy at the time of departure, as the Certificate of Airweight was invalid.
- The aircraft had been operated for several hours following an incomplete maintenance inspection caused by wing spar corrosion.