ERA11LA417 · Ryan Aeronautical ST3KR

The pilot stated that he conducted a thorough preflight inspection of the two-place tandem-seat airplane, and determined that there were 12 gallons of fuel onboard for the intended 30-minute flight, which he calculated should have consumed 4 gallons of fuel. After checking the fuel quantity, the pilot initially had the passenger order fuel but subsequently decided to forego the order once he determined its arrival would be delayed. The passenger confirmed that the fuel quantity sight gauge, located on top of the fuel tank forward of the front windshield, indicated a fuel level between the 10- and 15-gallon marks.

After an uneventful engine runup, the pilot, flying from the rear seat, attempted a takeoff. However, after adding power, the engine began to run roughly, and the pilot aborted the takeoff. The pilot performed another engine runup and then took off with no additional anomalies noted. About 25 minutes after engine start, the pilot made an approach to a private airstrip for landing but then opted to go around. During the go-around, witnesses heard the engine lose power, regain it, and lose power again. The pilot checked that the fuel selector was in the "Reserve" position, the magnetos were on, and the carburetor heat was off. The airplane then descended into a corn field and nosed over after landing, coming to rest inverted. Postaccident examination of the airplane revealed no preexisting mechanical anomalies and no fuel in the fuel tank; however, the fuel sight gauge on top of the fuel tank was broken, and likely allowed any remaining fuel to drain out of the tank when the airplane was upside down.

Before-landing procedures called for the fuel selector to be moved from the "Main On" position to the "Reserve" position, which would have allowed the bottom 3 gallons of the 24-gallon fuel tank to flow to the engine. However, the fuel selector valve was found in the "Main On" position, and damaged wreckage surrounding it confirmed that it was in that position upon ground impact. Pilot operating manual fuel consumption rates indicate scenarios where the available 9 gallons could have been consumed during the flight. However, exact consumption rates for the profile flown could not be determined, and the passenger, who was sitting in the front seat, stated that he saw between 5 gallons and 10 gallons of fuel indicated on the sight gauge when engine power was lost.

Engine anomalies occurred twice after the pilot added power: during the initial takeoff attempt, and again during the go-around attempt. With an outside air temperature of about 84 degrees F and a dew point of about 75 degrees F, the probability of carburetor icing at glide and cruise power existed. However, it is not known what effect the addition of carburetor heat might have had on the loss of engine power during the go-around attempt.

Verbatim NTSB analysis and probable cause from the NTSB dataset