Cessna R172K, VH-XPA, Bunbury, Western Australia, on 10 September 1990

Circumstances:

The pilot planned a short flight to Bunbury prior to boarding an international flight from Perth Airport that afternoon. He dipped the fuel tanks and checked the fuel gauge reading against the fuel calibration card, concluding that the aircraft contained about 70 litres of fuel, which was sufficient for the intended flight. Enroute to Bunbury, the pilot noticed that the fuel usage appeared higher than normal but did not take any action to remedy the situation, beyond leaning the mixture. The pilot noticed that both fuel tank indicators were approaching empty when he broadcast the inbound to Bunbury radio transmission. He was not concerned, as a check of the fuel gauge calibration card indicated that there were still 40 litres remaining. Eleven kilometres from Bunbury, the engine stopped and except for one brief burst of power would not restart. The pilot attempted to enter a forced landing pattern two or three times but had to change the selected landing area on each occasion due to a proliferation of power lines in the area. The aircraft eventually touched down on the bank of a river and overturned. A check of the aircraft found that eight and a half litres of fuel remained in the system, this was three and a half litres less than the published unusable fuel for the aircraft. Perusal of the aircraft records indicated that an error had been made during the latest fuel gauge calibration, and the fuel gauge calibration card was inaccurate. It is probable that the aircraft contained much less than 70 litres on DEPARTURE. The pilot sustained facial lacerations when the aircraft overturned on landing. He was not wearing the shoulder portion of the lap/sash seat belt. It is probable that there would have been no injuries if the complete belt had been worn.

Significant Factors:

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

1. Inaccurate fuel gauge calibration chart.

2. Fuel exhaustion resulting in a forced landing on unsuitable terrain.

3. The pilot did not ensure that the complete seat belt was fastened.