Forced/precautionary landing involving a Piper PA-31, VH-WAL, 6 km north-north-east of Maitland (ALA), New South Wales, on 12 November 1997

The pilot was conducting a scheduled freight run and earlier that day had refuelled the aircraft and departed Bankstown with full main tanks (401 litres) and 160 litres in the auxiliary tanks. The accident flight was on the Scone to Maitland sector, and the pilot reported that when departing Scone, the aircraft had about 108 kilograms of freight and 430 litres of fuel.

The pilot reported that while on descent and at about five miles from Maitland, the right engine RPM began to fluctuate with an accompanied increase in vibration. The pilot, thinking that it was a malfunction of the propeller governor, reported that he shut down the right engine and selected the right propeller to feather.

The pilot observed that the right propeller was still windmilling, the indicated airspeed was decreasing and that the aircraft was unable to maintain height, so he elected to land in a nearby field. He closed the left throttle and selected the landing gear down. The landing gear collapsed on touchdown as there had been insufficient time for it to extend and lock. The aircraft slid for about 120 metres.

Investigation of the fuel system indicated that the auxiliary tanks were empty while the main tanks each contained about 140 litres. The cockpit fuel selectors indicated that the main fuel tanks were selected.

Investigation of the engines and their systems, including the propellers and governors, could not determine the reason for the reported propeller malfunction or the inability of the aircraft to maintain height.