Accident Sequence
The pilot reported that after topping off the fuel tanks in Gallatin, Tennessee, he had 60 gallons of fuel onboard. Departing at 0625 central daylight time, he climbed to 9,000 feet, with a flight duration of 3 hours 30 minutes. He leaned the fuel mixture, observing fuel flows of about 10.5 to 11 gallons per hour on his JPI analyzer, and noted that the quantity of fuel remaining never dropped below 20 gallons. Upon reaching the destination airport, he overflew the airport to observe winds, then flew 6 miles south, circling a friend's house twice, before returning to land. During the approach, while turning to base, he applied 30 degrees of flaps, at which point the engine ceased operating. He stated that obstacles included trees and utility wires. During the glide, after avoiding trees, he selected 40 degrees of flaps in an attempt to balloon over the wires, but the airplane stalled and descended, impacting the ground.
Witness Observation
A witness stated that he saw the accident airplane on downwind, rocking its wings, and observed it on final approach as it came over the trees. He noted that the propeller had stopped rotating. As he continued watching, it appeared as though the pilot was trying to stretch the glide. He then saw the airplane stall and descend, impacting the ground a short distance from the runway.
Post-Accident Inspection
An FAA inspector responded to the accident scene and found no evidence of fuel spillage. When the airplane was checked, the inspector found about 2 gallons of fuel in the left tank and no fuel in the right tank. On March 10, 2006, an FAA-licensed mechanic, under the supervision of the FAA inspector, conducted a detailed examination of the airplane's airframe and engine, with no anomalies noted. The pilot stated in his report to the NTSB that there were no mechanical failures or malfunctions to the airplane or any of its systems. The accident airplane was equipped with a Texas Skyways Incorporated conversion O-520-U/TS engine.
Fuel Consumption Analysis
On July 17, 2007, a technician at Texas Skyways stated to the NTSB that the company did not publish endurance documentation for their conversions due to the various models of engines they modified and their variability in fuel consumption. He further stated that, from his experience, climb to cruise fuel consumption for the O-520-U/TS engine, at a rate of climb of about 1,000 feet per minute at full power without leaning for altitude changes, would yield a fuel consumption of about 23 gallons per hour. With leaning the mixture and other climb-related adjustments, the average fuel consumption during climb should be about 18 gallons per hour. At an altitude of 9,000 feet, the technician estimated that the airplane should consume about 14 gallons per hour in cruise flight. Additionally, he said that JPI endurance data was consistent with the exhaust and cylinder head temperatures noted.