Grumman AA-1B N8998L accident near Chesnee, South Carolina

Probable cause

A loss of engine power in flight due to fuel starvation as a result of the pilot's inadequate inflight fuel planning and the pilot's failure to maintain airspeed while descending for a forced landing.

NTSB analysis

A witness reported that the accident airplane flew over his house and the engine sounded as if it was running slowly. The wings were rocking from side to side. As he continued to watch the airplane, the engine stopped running and the airplane descended until it crashed. The airplane impacted the ground in about a 35-degree nose-low attitude. Each wing leading edge had accordion type damage along the entire length. Examination of the fuel tanks found that they were not breached or damaged. The fuel tanks were drained; 3 gallons of fuel were recovered from the left tank and 1.5 gallons of fuel were recovered from the right tank. The recovered fuel included approximately 1 gallon from each tank that the airplane manufacturer considered unusable. The fuel selector was found in the off position. Examination of the airframe and engine did not reveal evidence of a preimpact malfunction or failure. In the month prior to the accident, the pilot was suffering from urinary symptoms that were interfering with his ability to obtain adequate sleep. Toxicology testing indicates that he had likely used at least one prescription sleep aid the night prior to the accident, in addition to relatively recent use of a sedating over-the-counter antihistamine and a prescription barbiturate medication. While the pilot’s extensive experience and the circumstances of the accident indicate the possibility that the pilot may have been distracted by physical symptoms, impaired by fatigue, or impaired by the effects of one or more of the medications he had recently ingested, the investigation was unable to determine conclusively that the pilot suffered from impairment or distraction.

Text from the NTSB. Open the NTSB docket for ERA09FA235 for the full record.