Piper J3C-65 N77522 accident near Groveland, Florida

Probable cause

The pilot’s inadequate fuel planning, which resulted in a total loss of engine power due to fuel starvation.

NTSB analysis

The pilot landed after a 1 1/2 hour flight. While attempting to refuel, he discovered that the airport’s self-serve fuel pumps were out of order. The pilot calculated that the fuel remaining in the airplane was 11 gallons and departed on the return flight without refueling. About 1 hour after departure, the engine lost total power, and the pilot performed a forced landing to wooded terrain. The airplane came to rest in a tree canopy about 31 miles from the destination airport. The airplane’s fuselage and right wing were substantially damaged during the accident sequence.

Postaccident examination of the airplane revealed that the carburetor and gascolator were absent of fuel. The fuel tanks were intact with no evidence of leakage; about 28 ounces of fuel were recovered from the right wing and about 1/2 gallon was recovered from the left wing. The fuel selector valve was plumbed backward between the left and right fuel tanks, and the header tank was not vented to the left fuel tank.

Considering the low fuel quantity, the unvented fuel header tank likely reduced head pressure to the carburetor and resulted in fuel starvation. Given the amount of fuel found in the fuel tanks after the accident, it is unlikely that there was sufficient fuel onboard to have completed the flight to the destination; however, due to the lack of documentation of modifications that had been performed to the fuel system, the amount of unusable fuel could not be determined.

There were no preaccident mechanical malfunctions or anomalies noted to the engine that would have precluded normal operation.

Text from the NTSB. Open the NTSB docket for ERA24LA328 for the full record.