Accident Overview
On January 21, 2020, at 1718 eastern standard time, a Grumman AA5B, registration N424WB, was substantially damaged in an accident near Tallahassee, Florida. The pilot sustained serious injuries, and the passenger received minor injuries. The flight was conducted under 14 Code of Federal Regulations Part 91 as a personal cross-country flight. Day visual meteorological conditions prevailed, and no flight plan was filed.
Flight History
The flight originated at Enterprise Municipal Airport (EDN) in Enterprise, Alabama, with a destination of Wauchula Municipal Airport (CHN) in Wauchula, Florida. The pilot reported that earlier that day, the aircraft's tanks were completely filled with 52 gallons of fuel. The pilot departed CHN around 0830, flew to EDN, and landed about 1230. Around 1400, the pilot departed EDN for CHN, planning to stop for fuel along the route but uncertain of the location.
During cruise at 10,500 feet, approximately 1.5 hours into the flight, the engine began to sputter. The pilot advanced the mixture control fully forward and activated the electric fuel pump. The engine ran more smoothly for a few seconds before sputtering again. The pilot contacted Tallahassee International Airport (TLH) control tower and declared an emergency. Shortly thereafter, the engine experienced a total loss of power.
Emergency and Landing
The pilot shut off the magnetos and pulled the mixture to shut-off. After priming the engine a few times, an attempt to restart resulted in the engine running for about five seconds before losing power again. The right fuel gauge indicated a little over one-quarter tank; the left fuel gauge was inoperative. At approximately 5,000 feet and 7 miles from TLH, the pilot determined the aircraft could not reach the runway and initiated an off-airport landing. Spotting a small sand pit surrounded by trees, the pilot slipped the aircraft to descend, but the left wing struck trees, and the aircraft impacted terrain. The pilot had no further memory of the accident.
Wreckage and Engine Examination
A Federal Aviation Administration inspector examined the wreckage at the accident site. No evidence of fuel leakage or fuel odor was found. Both fuel caps were removed, and no fuel was observed or smelled in the tanks.
The engine remained partially attached to the airframe via the lower tubular engine mounts, which were impact-damaged. The carburetor was fractured across the throttle bore and partially separated. The left magneto was impact-damaged and partially separated. The engine was removed and partially disassembled. Hand-rotation of the propeller showed continuity of the crankshaft to the rear gears and valve train. Compression and suction were observed from all four cylinders; borescope inspection revealed no anomalies. The throttle, mixture, and carburetor heat controls were found fully forward. A small amount of blue liquid with an odor consistent with aviation gasoline drained from the hose connecting the engine-driven fuel pump to the carburetor. The carburetor was partially disassembled; the composite fuel float and internal components were undamaged, and the fuel bowl was about half full of blue liquid. A water-finding paste test showed no color change. The carburetor fuel inlet filter was clean. About one tablespoon of blue liquid drained from the engine-driven fuel pump, which functioned properly when the actuator arm was hand-operated with the inlet submerged in fuel.
Both magnetos produced spark from all ignition leads when rotated. Spark plug electrodes were worn; the No. 1, 2, and 4 top and bottom electrodes showed gray coloration, while the No. 3 electrodes were dark gray.
The Pilot's Operating Handbook for the Grumman AA5B states a total fuel capacity of 52 gallons, with 51 gallons usable, and an average fuel burn of 10.2 gallons per hour at 2700 rpm and 10,000 feet cruise. No pilot or aircraft logbooks were available for review.