Forced/precautionary landing involving a Beech Aircraft Corp C23, VH-UMK, Rose Hill Racecourse, New South Wales, on 23 July 1995

Whilst transiting the lane of entry outbound to Cessnock the pilot reported that the engine started to vibrate. The aircraft was turned onto a reciprocal heading to return to Hoxton Park, but the engine began to run roughly. The use of carburettor heat had no effect, and engine RPM began to decrease. The pilot elected to carry out a forced landing on a racecourse, but during the landing roll the aircraft collided with a barrier fence.

Investigation later revealed that all spark plugs were in poor condition, with heavy erosion to the centre electrodes indicating considerable operating time. Both plugs in number 1 cylinder had broken ceramics and the electrode gaps were closed. One plug in number 4 cylinder was fouled with lead. An engine run later confirmed that the inlet valves in number 3 and 4 cylinders were also sticking.