What happened
On 1 June 2007, a Piper PA30, registration ZS-JCJ, was conducting conversion training at Wonderboom Aerodrome. The flight, consisting of a flight instructor and a student, was performing a series of touch-and-go landings. During the first touch-and-go of the afternoon session, the student pilot flared the aircraft too high, resulting in a hard landing.
Following the impact, the instructor took control of the aircraft to demonstrate proper technique. While attempting to retract the landing gear, the instructor noted that the gear-up warning light failed to activate. After a flyby, the air traffic controller observed that the undercarriage appeared to be in the retracted position. When the instructor attempted to extend the gear, the mechanism failed to lock into the down position. The instructor subsequently deployed the emergency extension system. A second flyby was performed, during which the controller confirmed the gear appeared to be down, allowing the aircraft to land safely and taxi to a maintenance hangar.
The investigation
Investigators examined the aircraft's undercarriage and discovered a crack in the right-hand trunion assembly. A discrepancy emerged between the statements provided by the aircraft maintenance organisation and the flight crew regarding the origin of the crack. To resolve this, the trunion underwent metallurgical analysis.
Findings
- The metallurgical report determined that the failure of the right-hand trunion was likely caused by a single induced overload force during flight.
- No evidence of pre-existing crack formation was identified during the analysis.
- The findings of the metallurgical study are consistent with the flight crew's report of a hard landing during the training session.