Piper PA 34-220T N9148B accident near Patterson, Louisiana

Probable cause

The pilot's inadequate in-flight fuel management, which resulted in a dual loss of engine power due to fuel exhaustion.

NTSB analysis

The commercial pilot was conducting an aerial observation flight to photograph an oil rig in the Gulf of Mexico that was located about 185 miles southwest of the departure airport. According to the pilot, before departing the operator's base to pick up passengers, fuel was visible "in each tank at the bottom of the sidewall," and the fuel gauges indicated about 45 gallons "a side." The pilot completed the 30-minute flight to pick up the passengers without incident. The rear cabin door was then removed to facilitate the photography. About 40 gallons of fuel remained in each tank at the time of the takeoff after picking up the passengers. The airplane arrived at the oil rig about 1.5 hours after departure; the flight was uneventful. The airplane circled the oil rig for about 1 hour to complete the photography. Afterward, the pilot established a return course. About that time, he noted that the fuel quantity gauges showed less fuel remaining than expected. He leaned the engine mixtures as much as possible and visually examined the airplane for a fuel leak but did not observe any such indication. The pilot elected to deviate to a closer airport due to low fuel. Both engines lost power about 1 hour into the return flight, and the pilot executed a forced landing to a canal, resulting in substantial damage to the airplane. One of the passengers stated that the pilot had informed him that the airplane had not been "topped off" but that sufficient fuel was on board for the flight.

A postaccident examination of the airplane did not reveal any anomalies that would have contributed to a dual loss of engine power. During the recovery process, no fuel sheen was observed on the water, and no fuel was observed in the fuel tanks. The total elapsed flight time from the operator's base to the accident site was 3.8 hours. The airplane's owner indicated that the airplane's hour meter ran only when the landing gear was retracted, so the engine run time when the landing gear was extended could not be determined.

The pilot's operating handbook for the airplane make and model noted a fuel flow of about 10 gallons per hour for each engine at economy cruise power. The handbook also stated that airplane cruise performance would be reduced by about 5 percent when the airplane was operated with the aft doors removed.

Text from the NTSB. Open the NTSB docket for CEN18LA093 for the full record.