Primary finding
Probable cause
Power loss due to a cracked intake valve pipe assembly. A factor was the lack of suitable terrain for the forced landing.
Investigator assessment
Analysis narrative
After making one spray pass, the pilot pulled up to make another pass. During the maneuver, the engine lost power and the airplane impacted an adjacent field. A mechanic who examined the engine reported finding damage on the intake side of the #5 cylinder, the intake valve retaining spring missing, and cracks in the intake pipe casting.
Source record
Factual narrative
On April 29, 1995, approximately 1040 central daylight time, a Gulfstream-Schweizer G-164B, N6746K, was destroyed during a forced landing near Morse, Louisiana. The commercial pilot was not injured. Visual meteorological conditions prevailed. The pilot told a Federal Aviation Administration inspector he had been spraying zinc fertilizer on a rice field. After making a spray pass, he pulled up and turned left to make another pass. Beyond this point, he could not remember any further details and there were no known witnesses to the accident. The pilot told his employer all he remembered was the airplane "just falling." In his pilot/operator report; however, the pilot said the "engine failed and aircraft lost altitude and impacted neighboring rice field." The FAA inspector who examined the wreckage noted the propeller blades were bent straight back with no twisting. Additionally, there were no chordwise scratching on the cambered surfaces of the blades. A mechanic later found damage to the intake side of the number five cylinder. The intake valve retaining spring was missing and there were cracks in the intake pipe casting. -