Collision with terrain involving Piper PA60-601P, VH-MNM, Warnervale, New South Wales, on 22 August 1989

Circumstances:

Earlier in the day the pilot had flown from Bankstown to Taree with an intermediate landing at Warnervale. Before departing Taree, the pilot said the oil quantities were checked for both engines and found to be adequate for the return flight to Bankstown via Warnervale. The track to Warnervale was via the coastal route of the Williamtown military control zone (CTR) at 500 ft. Leaving the CTR, the pilot initiated a cruise climb to 3,000 ft. Passing 700 ft, the left engine began to vibrate and lost power. The engine was shut down and the climb continued to 1,500 feet. The pilot decided to continue to Warnervale rather than divert to RAAF Williamtown which was closer. He unsuccessfully attempted to restart the left engine whilst tracking to Warnervale. On arrival, the aircraft was positioned to join the circuit on an oblique left base for runway 20. As the aircraft passed over the threshold with the landing gear and full flap extended, the pilot applied full power and commenced a missed approach when he assessed the aircraft was too high and too fast. The rate of climb was less than anticipated following gear and flap retraction and when it became apparent the aircraft might collide with trees beyond the southern boundary of the airstrip, the pilot elected to land wheels-up on the overrun. The aircraft slid along swampy ground and collided with a large eucalypt log. During a subsequent strip examination, it was determined the left engine oil quantity was low. Glazing was also observed in several cylinder bores. As the engine design incorporated hydraulic tappets, it is considered probable that the low oil quantity affected the operation of the tappets and caused the vibration and loss of power. The reason for the apparent rapid loss of oil from the left engine after DEPARTURE Taree was not determined.

Significant Factors:

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

1. Vibration and loss of power in flight from the left engine which required the engine to be shut down.

2. The pilot failed to divert to the most suitable airport.

3. The pilot misjudged height and speed on approach to runway 20.

4. The pilot attempted a single engine missed approach from an unsafe height.