On July 19, 1989, a Schweizer G-164A (registration N48377) was involved in an aviation accident near Lake Arthur, LA. Investigators recorded the probable cause as: LOSS OF ENGINE POWER FOR UNDETERMINED REASONS. THE HIGH WEEDS (VEGETATION) & LEVEE (DIRT BANK) WERE CONSIDERED TO BE RELATED FACTORS. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A pilot experiencing a manifold pressure loss during takeoff from a 1,600-foot grass strip veered right, striking high weeds and a levee, resulting in the airplane ending up inverted. No cause for the power loss was identified.
Incident Overview
During a takeoff roll on a 1,600-foot grass airstrip, the pilot observed a reduction in manifold pressure. Initially set at 36 inches, the pressure dropped to 28 inches when the aircraft was approximately three-quarters of the way down the strip. The pilot initiated a load dump and, upon reaching the end of the airstrip, veered the airplane to the right.
Sequence of Events
As the airplane turned, the right wing entered high weeds and the left landing gear struck a small levee. The impact caused the aircraft to come to rest in an inverted position. The pilot had started the takeoff roll with 36 inches of manifold pressure and noticed the decrease during the roll.
Investigation Findings
Subsequent examination of the aircraft and engine systems did not reveal a reason for the loss of manifold pressure. The investigation concluded that no mechanical or operational cause could be determined for the power reduction.