Pilot Debrief

GRUMMAN AMERICAN AVN. CORP. AA1B near Chester, SC — 2014-05-23

Final reportERA14FA260
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Date
2014-05-23
Location
Chester, SC, USA
Aircraft
GRUMMAN AMERICAN AVN. CORP. AA1B
Registration
N8890L
Category
Airplane
Highest injury
Fatal
Fatalities
2
Phase of flight
Cruise

Probable cause

The pilot's inadequate inflight fuel monitoring, which resulted in fuel exhaustion and the subsequent total loss of engine power. Contributing to the accident was the loose fuel cap, which allowed fuel to syphon out in flight.

Contributing factors

Contributing to the accident was the loose fuel cap, which allowed fuel to syphon out in flight.

NTSB narrative

The airplane departed on a cross-country flight after the pilot purchased 11.92 gallons of fuel. A flight plan found in the wreckage with the accident pilot's name on listed the fuel onboard as 3 hours and 30 minutes and a flight distance of 240 miles. The airplane wreckage was located about 130 miles from the departure airport. Postaccident examination of the propeller indicated that the engine was not producing power at impact. Examination of the wreckage and surrounding vegetation revealed no evidence of fuel within the fuel tanks and only slight amounts of blight, consistent with fuel spillage, on nearby vegetation at the accident site. Fuel staining was observed on the right wing, and the fuel cap did not have a detent. If the pilot had performed a preflight inspection of the airplane before departure, he would have noticed the fuel staining; thus it likely occurred during the accident flight, although it could not be determined why the pilot did not notice the loose fuel cap. Given the distance flown and cruise speed, the airplane's published fuel consumption indicates that the airplane would have consumed about 11 gallons of fuel in the 90 minutes of flight. Although both fuel tanks likely contained enough fuel for a flight longer than 90 minutes at takeoff, it is likely that any fuel in the right fuel tank was syphoned out during flight due to the loose fuel cap. Even though the estimated fuel consumption calculations showed that the total quantity consumed was less than what was indicated the flight plan, the lack of fuel observed at the accident site and the lack of evidence of any preexisting mechanical anomalies indicate that the total loss of engine power was likely the result of fuel exhaustion. Although the fuel selector valve's Teflon plunger was found fractured, which resulted in the selector valve binding, the fracture was consistent with impact damage. The airplane was not reported overdue for several days and was located in a wooded area about 3 days after it had departed. The airplane's emergency locator transmitter (ELT) unit had an "ON/OFF/ARM" switch that was found in the "OFF" position. The ELT may have been deactivated by first responders; however, given that there were no reports of ELT signals being detected in the area from the day of the accident until the airplane was located, the ELT was likely in the "OFF" position before the flight and did not activate due to the switch position, which delayed the search and rescue of the occupants.

Analysis

Primary failure mode
Fuel management
First missed decision gate
Pilot did not refuel before continuing to destination, leading to fuel exhaustion.

NTSB coding

Evidence available

  • ADS-B / radar
  • 16 docket documents
View NTSB final reportView NTSB docket

Docket documents16

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