Casualties unknown

2001-01-10: Grumman American AA-1B (N9988L) — Smith, Douglas A. — Cottage Grove, OR

Cottage Grove, OR, US

On January 10, 2001, a Grumman American AA-1B (registration N9988L) operated by Smith, Douglas A. was involved in an aviation accident near Cottage Grove, OR. Investigators recorded the probable cause as: The flight instructor's failure to ensure (supervision) the student had an adequate supply of fuel available, and the student's failure to refuel the aircraft sufficently resulting in a fuel starvation/exhaustion condition and total power loss. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 1781061362Data APIEditorial standards

During a touch-and-go landing, a Grumman AA-1B's engine stopped abruptly at low altitude. The instructor took control, avoiding trees, but the aircraft impacted trees in a forced landing. Carburetor icing conditions were present.

Flight Profile

The instructor, acting as pilot-in-command, and the student, who owned the aircraft, conducted a preflight fuel check. They believed the left fuel tank contained approximately 1/4 and the right tank 3/4 of capacity. The flight included airwork at high altitude followed by pattern work for touch-and-go landings.

Power Loss

During the initial climb after the first touch-and-go landing, at an altitude no more than 200 feet above ground, the engine abruptly ceased operation. The propeller was reported to stop rotating. The instructor assumed control, maneuvering the aircraft away from trees toward a potential landing site. Meanwhile, the student selected the right fuel tank and activated the fuel boost pump but did not engage the starter.

Forced Landing and Impact

The aircraft struck trees during the forced landing.

Post-Accident Examination

Fuel and aircraft log records indicated that under optimal conditions, assuming full tanks (22 gallons usable fuel on September 29, 2000), the aircraft had consumed a total of 35.6 gallons of usable fuel over 7.4 Hobbs hours from that date to the accident time, yielding an average burn rate of approximately 4.81 gallons per hour. The fuel selector was positioned on the left tank at the time of power loss and was found on the right tank at the accident site. Post-accident inspection of the fuel system confirmed it was capable of delivering fuel to the carburetor. The engine was examined and no anomalies were found. The carburetor underwent a flow check and disassembly, revealing no discrepancies. Serious carburetor icing conditions were determined to exist at the time of the accident.

Aircraft Information

The aircraft was a Grumman AA-1B.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20010118X00326. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.