Piper PA-20 N7746K accident near Elgin, South Carolina

Probable cause

A total loss of engine power due to fuel exhaustion resulting from the pilot’s inadequate preflight planning. Contributing to the accident was that the pilot did not maintain an adequate airspeed, which resulted in an aerodynamic stall.

NTSB analysis

The pilot was on a cross-country flight and no flight plan was filed. While en route, a witness observed an airplane flying at a slow airspeed between 200 and 300 feet above the ground behind his place of business. The engine was revving up and down as if it was running out of fuel. The witness observed the nose pitch up to an attitude between 35 and 40 degrees, and then the nose pitched straight down. The airplane went below the tree line, then there was an explosion and a postcrash fire.

Examination of the crash site revealed no anomalies with the airframe, engine assembly, or accessories. The fuel selector was found positioned to the right main fuel tank. The right main fuel tank had ruptured and was absent of fuel.

The airplane has two 18-gallon fuel tanks with a total capacity of 36 gallons. The cruise airspeed for the airplane is 126 mph. The straight-line distance from the departure airport to the crash site is 607 miles. According to the engine-operating manual, the engine will burn 7.2 gallons of fuel per hour at 75-percent power and 6.3 gallons of fuel per hour at 65-percent power. In a no wind condition at 75-percent power, it would take 4 hours and 50 minutes to fly from the departure airport to the accident site; at 65-percent power it would take 5 hours and 33 minutes to fly to the accident site. Based on a straight line, no wind, and non-maneuvering flight profile, available fuel range would be about 523 nautical miles. These calculations do not account for fuel consumed during the start, taxi, and take off sequence. Thus, the pilot exceeded the fuel endurance, and the engine lost power. Also, the high-pitch attitude of the airplane observed by the witness could have resulted in the stall.

Text from the NTSB. Open the NTSB docket for ERA11FA210 for the full record.