On September 29, 2007, a Grumman G-164A (registration N8761H) was involved in an aviation accident near Pittsgrove, NJ. Investigators recorded the probable cause as: A partial loss of engine power due to low compression for undetermined reasons. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
While maneuvering at 50 feet after a spray run, a pilot heard a pop, the airplane descended, and despite applying power with rpm reaching 2300-2400, it collided with the ground and nosed over. Post-accident engine inspection revealed low compression in three cylinders, but the cause could not be determined.
Accident Sequence
The pilot was maneuvering the airplane at an altitude of 50 feet after completing a spray run. During the maneuver, a "pop" sound was heard. Immediately afterward, the airplane began to descend. The pilot responded by applying power, and the engine rpm increased to between 2300 and 2400 rpm. Despite this, the airplane collided with the ground and nosed over inverted during the subsequent forced landing.
Engine Inspection
Following the accident, the engine was removed from the airframe and a partial disassembly was performed. A compression test was conducted, which revealed that three cylinders exhibited low compression. No other anomalies were noted during the inspection of the engine. The specific cause of the loss of cylinder compression could not be determined.