Maule M7 N126MC accident near Colton, New York

Probable cause

The pilots' initiation of an uncoordinated right turn with the fuel selector positioned to the right main fuel tank, which had a low quantity of fuel in it and resulted in a total loss of engine power due to the unporting of the fuel and subsequent fuel starvation.

NTSB analysis

The private pilot was conducting a personal flight in the amphibious airplane, which he had recently purchased from the commercial pilot who was onboard the airplane. The private pilot stated that he entered a 30° right bank turn and that, about 6 to 7 seconds into the turn, the engine lost total power. The commercial pilot tried to restart the engine while the private pilot leveled the airplane and looked for a place to land. The commercial pilot told the private pilot to switch the fuel selector from the right main tank to both tanks, which he did, but the engine would not restart. The commercial pilot took control of the airplane and subsequently conducted a gear-up, forced landing to a field, which resulted in substantial damage to both floats, the wing struts, both wings, the fuselage, and the firewall.

Postaccident examination of the fuel system revealed no evidence of any mechanical malfunctions or failures that would have precluded normal operation. The commercial pilot reported that the right main tank had about 5 to 7 gallons of fuel in it when the airplane entered the right turn and that the engine "definitely died due to fuel starvation," which had happened to him before when he owned the airplane. According to the airframe manufacturer, in an uncoordinated turn, it is possible to unport fuel to the lines that carry fuel to the engine, which would result in a power loss. The chances of a loss of engine power occurring increases when there is a low quantity of fuel in the tank. Therefore, it is likely the fuel unported during the right turn because the right tank was low on fuel, which resulted in fuel starvation and the subsequent loss of engine power.

Text from the NTSB. Open the NTSB docket for ERA17LA188 for the full record.