Cessna 404, VH-TMU, Pormpuraaw East, Queensland, on 17 August 1990

Circumstances:

Shortly after full power was applied for take-off, the pilot noticed that the aircraft was tracking to the left of the strip centre. He turned gently right to correct the situation, and the nose gear leg collapsed soon after. Metallurgical examination concluded that the nose gear leg mounting trunnions contained fatigue cracks. One trunnion had failed during this take-off. The aircraft had accrued almost 20,000 hours and an inspection recommended by the aircraft manufacturer less than one year prior to the accident had not been conducted. Had the inspection been conducted, the fatigue cracks should have been detected. Some time after this aircraft was manufactured the manufacturer altered the design of the mounting trunnions to make them stronger.

Significant Factors:

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

1. Nose leg mounting trunnions of weaker design than later versions.

2. The operator had not conducted inspections recommended by the manufacturer.

3. The aircraft was frequently operated on rough strips.

4. Fatigue fracture of the nose gear mounting trunnion.