Introduction
On September 17, 2017, at about 1600 eastern daylight time, a Cessna 177B airplane, registration N35170, sustained substantial damage during a forced landing following a complete loss of engine power near London, Ohio. The flight instructor and student pilot were not injured. The airplane's right-wing spar was bent, and the fuselage was wrinkled aft of the cabin. The flight was conducted as an instructional flight under Title 14 Code of Federal Regulations Part 91 in visual meteorological conditions. The local flight originated from Madison County Airport (UYF) at about 1415, performed a landing at Lima Allen County Airport (AOH), and was returning to UYF when the accident occurred.
Accident Sequence
The instructor pilot reported that after making a full stop landing at AOH, they started the return flight to UYF. During a descent about 6 to 7 miles from UYF, the engine "sputtered" several times and then stopped producing power. The instructor established a proper glide speed and checked the fuel selector to ensure both fuel tanks were selected. He noted that the fuel pressure was low and fluctuating. The engine restarted for several seconds after the electric fuel boost pump was turned on, then stopped producing power again. After making several turns to find a suitable landing area, he landed the airplane in a corn field.
Fuel Management
The pilot noted that the airplane's engine had been recently overhauled and was being operated at high power settings and a full rich mixture for engine break-in. During previous flights, fuel consumption was about 11 gallons per hour (gph). Before the accident flight, he checked the fuel quantity and was confident that there were 25 gallons of fuel on board. The engine recording tachometer read 2069.3 hours prior to the flight and indicated 2,070.6 hours at the time of the accident. Based on previous fuel consumption and tachometer readings, the pilot calculated that about 14.3 gallons of fuel should have been consumed. Examination of the airplane at the accident site revealed no usable fuel in either wing tank and no breaches of the fuel system. Because the airplane was not being operated at normal cruise power settings, fuel burn calculations based on information in the Pilot's Operating Handbook could not be made.
Examination and Testing
A subsequent examination and testing of the airplane was performed by a third party after its removal from the accident site and after wing removal. The airplane was placed in a hangar, and after one day minor fuel stains were observed under the airplane. To further investigate if there was significant fuel leakage, the airplane was outfitted with a temporary fuel container secured to the cabin roof and plumbed into the left and right wing tank fuel line assembly inlets. The airplane's engine was run on two separate occasions using left, right, and both fuel selector positions, and with and without the electric fuel boost pump running. The engine speed attained during the test was 1,400 to 1,500 rpm, and the engine ran smoothly in all fuel configurations. Thorough examination of the airplane after each run did not reveal any fuel leakage, and fuel consumption was not excessive.