CHI96LA186

The pilot reported that he was at 200 feet turning for a spray run and the engine began 'running very rough, some smoke and oil noticed.' He conducted a forced landing in an 'open, rough field which had recently been saturated with heavy rain fall. Upon touch down, the main wheels began sinking in the mud and caused the aircraft to slowly flip forward....' The owner of the airplane reported that the engine was properly serviced prior to flight. Examination of the engine revealed five cracked cylinders and a master rod failure. The chief inspector of the FAA approved overhaul facility that examined the engine reported that 'the damage found during disassembly was typical of other engines known to have been oil starved during operation. The cause of oil starvation in this engine is unknown.'

On May 25, 1996, at 0830 central daylight time, a Grumman G-164-B airplane, N48518, operated by Gasper Airspray, Inc., sustained substantial damage when it nosed over during a forced landing, following a total loss of engine power, near Crookston, Minnesota. The solo commercial pilot reported no injuries. The aerial application flight originated about 0800 and was conducted under 14 CFR Part 137. A flight plan was not filed for the local flight and visual meteorological conditions prevailed.

The pilot reported that he was at 200 feet turning for a spray run and the engine began "running very rough, some smoke and oil noticed." He conducted a forced landing in an "open, rough field which had recently been saturated with heavy rain fall. Upon touch down, the main wheels began sinking in the mud and caused the aircraft to slowly flip forward...."

The Federal Aviation Administration Inspector who examined the airplane reported that it was moved prior to his arrival at the accident site. He reported that the engine had failed catastrophically. He observed five cracked cylinders and suspected a master rod failure.

The owner of the airplane reported that the engine had been run about 100 hours since overhaul. He said that there was oil on the ground in the vicinity of the accident site and that he was confident the engine was properly serviced with oil prior to the flight. He reported that examination of the propeller governor was conducted by an FAA approved repair station which reported the governor was servicable.

The engine was examined by an FAA approved engine overhaul facility. The chief inspector reported that "master rod bearing failure typical of oil starvation had occurred.... The damage found during disassembly was typical of other engines known to have been oil starved during operation. The cause of oil starvation in this engine is unknown."