Accident Overview
On 1 June 2007, a Piper PA30 (registration ZS-JCJ) was conducting a conversion training flight at Wonderboom Aerodrome (FAWB). The aircraft was operated under an approved training organization certificate, and both the flight instructor and student held valid licences. The flight was the second of the day, following an uneventful first flight that included several touch-and-go landings.
Sequence of Events
After a lunch break, the student pilot performed a touch-and-go landing but flared the aircraft too high above the runway, resulting in a hard landing. The flight instructor then assumed control to demonstrate the correct technique. When the instructor attempted to retract the landing gear, the gear-up light did not illuminate. The instructor requested a low flyby past the control tower, and the air traffic controller visually confirmed that the undercarriage appeared to be up.
Subsequently, when the instructor selected gear down, the undercarriage failed to lock into place. The instructor employed the emergency gear extension system to lower the landing gear. Another flyby was performed, and the controller confirmed that the gear appeared to be down. The aircraft landed without further incident and was taxied to an aircraft maintenance organisation (AMO) hangar for inspection.
Investigation Findings
An inspection revealed a crack in the right-hand trunnion assembly. During the investigation, a discrepancy emerged between statements from the AMO and the student pilot regarding the cause of the crack. The trunnion was sent for metallurgical analysis, which concluded that the failure most probably resulted from a single overload force during operation, with no clear indications of pre-failure crack formation. This finding aligned with the flight crew’s report of a hard landing.
Maintenance and Certification
The aircraft had most recently undergone a mandatory periodic inspection (MPI) certified by an AMO holding valid approval number 278, expiring on 31 October 2007. The South African Civil Aviation Authority had audited this AMO on 5 September 2006. The flying school held a valid Aviation Training Organisation and Approval Certificate (no. CAA/0274) issued on 6 December 2006 and valid until 6 December 2007.
Conclusion
The right-hand trunnion assembly failed due to overload following a hard landing.