This May 2008 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
Aircraft: Piper Cherokee. Injuries: 5 Minor. Location: Millinocket, Maine. Aircraft damage: Substantial.
What reportedly happened: The pilot, who had logged 154 hours, including 16 in make and model, rented the plane for a camping trip. The flight to the destination, according to the pilot’s calculations, would take about three hours. He determined that the plane would consume 14 gallons per hour. With five people and camping gear onboard, the pilot was able to fill both main fuel tanks, and partially fill the left tip tank for a total of 60 gallons of fuel. Following the takeoff, the pilot climbed to 5,500 feet, and set the power for approximately 65% . The mixture was leaned, and set about half way between full rich and idle cutoff. However, within the first hour of flight the pilot noted the engine oil temperature near the upper end of the green zone and added about one inch of mixture control lever stroke to help cool the engine. This resulted in a greater fuel consumption. The pilot first exhausted the fuel from the left tip tank, then alternated utilizing the left and right fuel main tanks every 30 minutes for most of the remainder of the flight. About 30 minutes prior to arriving at the destination airport, while passing near an en route city, the pilot observed approximately 14 gallons of fuel remaining, which he equated to 1 hour of flight time. About half way between the city and the destination, the pilot descended to 3,500 feet, and shortly thereafter, the fuel was exhausted from the left tank. The pilot switched to the right tank, but about two miles from the destination the airplane ran out of fuel and the engine quit. The pilot then glided the airplane toward the airport, and cleared trees, but the main landing gear clipped a perimeter fence before the airplane landed on a road and rolled into a ditch. No mechanical issues were found.
The pilot noted that, in hindsight, he wished he had calculated fuel burn prior to reaching the en route city.
Probable cause: The pilot’s failure to properly monitor fuel consumption during the flight.
For more information: NTSB.gov