ERA13FA096 · Piper PA-31-350

The pilot and the pilot-rated passenger were flying from their home located at a residential airpark, where no fuel services were available, to an airport located about 37 nautical miles away. Shortly after departing on the flight, the passenger queried the pilot when she noticed the airplane's low fuel state. The pilot responded that one of the fuel gauges always reported a greater quantity of available fuel than the other, and that if necessary they could utilize needed fuel from the tank with the higher reported fuel quantity. About 15 minutes after departure, the pilot advised air traffic control that the airplane was critically low on fuel, and about 5 minutes later the airplane impacted trees and terrain after all fuel had been exhausted and both engines ceased producing power.

Examination of the airframe and engines after the accident confirmed that all of the airplane's fuel tanks were essentially absent of fuel, and that the trace amounts of fuel recovered were absent of contamination. Post-accident testing of the fuel quantity senders showed that both of the applicable units failed to meet the indicated electrical resistance tolerances published in the service manual for the full fuel position, and only one of the units was within the tolerance for the empty position.

Based on the autopsy and toxicology results, the pilot had emphysema, hypertension, dilated cardiomyopathy, and severe coronary artery disease; however, given that the passenger seated in the right seat of the airplane did not report any signs of acute incapacitation, and that the pilot did not communicate any medical issues to air traffic control, it does not appear that these conditions affected his performance on the day of the accident.

The pilot did not report any chronically painful conditions to the FAA in his most recent medical certificate applications, however, the post-accident toxicology identified that the pilot was taking several pain medications (diclofenac, gabapentin, and oxycodone), and one illegal substance (marijuana). Based on the medications' Food and Drug Administration warnings, gabapentin and oxycodone may be individually impairing and sedating; their combined effect may be additive. The effects of the underlying conditions that necessitated the medication could not be determined. It is impossible to determine from the available information what direct effect the marijuana alone may have had on the pilot's judgment and psychomotor functioning; however, the combination of marijuana, oxycodone, and gabapentin likely significantly impaired the pilot's judgment and contributed to his failure to ensure the airplane had sufficient fuel to complete the planned flight.

Verbatim NTSB analysis and probable cause from the NTSB dataset