Forced/precautionary landing involving a Hiller UH-12E, VH-LUN, Moriarty (9 km south-east of Devonport), Tasmania, on 20 February 1994

The pilot reported that while flying at 350 feet above ground level, maintaining 50 knots, the engine started to vibrate violently and lose power until it stopped. Prior to the power loss, all temperatures and pressures were normal. The pilot entered autorotation but due to the unsuitable terrain he had to make a very steep descent to put the aircraft onto a suitable landing site. In doing this, he made a heavy touchdown which resulted in a main rotor blade striking the tail boom causing substantial damage.

The engine failure was later determined to have been caused by failure of the number two connecting rod assembly. The failure of the assembly was caused by fatigue crack growth in the connecting rod cap. The factors that contributed to the fatigue crack initiation were not determined.