What happened
On 25 May 2003, a Jabiru SP microlight, registration ZU-CKK, was conducting a private pleasure flight near Grand Central Aerodrome (FAGC). The aircraft, carrying a pilot and one passenger, had departed from and intended to return to the same aerodrome.
Upon touchdown on Runway 35, the pilot observed two birds on the runway surface. In an attempt to avoid a potential bird strike, the pilot applied the brakes. During this braking maneuver, the right-hand undercarriage collapsed, causing the aircraft to veer off the right side of the runway. There were no injuries to the occupants, and the aircraft sustained no structural damage beyond the failed landing gear.
The investigation
Investigators examined the mechanical condition of the aircraft and its maintenance history. At the time of the incident, the aircraft held a valid Authority To Fly. Records indicated that the most recent annual inspection had been completed on 12 June 2003, with the aircraft having flown an additional 38.2 hours since that inspection.
Findings
Technical examination of the right-hand undercarriage leg identified the specific mechanical failure. The investigation established that the lock nut on a landing gear retaining bolt had stripped, which directly led to the collapse of the undercarriage during the landing roll.