Piper PA-28-161, VH-BZB, Lilydale, Victoria, on 22 December 1989

Circumstances:

The aircraft was being used for dual circuit training. Following a normal touch down a loud bang was heard, the nose dropped, and the aircraft skidded to a halt with the nose gear collapsed. The nose landing gear strut had fractured at the base of the cylinder. Microscopic examination of the fracture surfaces found a single event overload failure by bending, with no evidence of any pre-existing defects. The failure mode suggests that the nosewheel was either cocked to the left or the aircraft was yawed to the left when the nosewheel contacted the runway.

Significant Factors:

The following factors were considered relevant to the development of the accident:

1. The nose landing gear strut had failed at the base of the cylinder due to a single event overload.

2. The nosewheel was cocked to the left, or the aircraft yawed to the left when the nosewheel contacted the runway.