Grumman Acft Eng Cor-Schweizer G-164 N6674K accident near Maxwell, California

Probable cause

The pilot's failure to visually check the fuel quantity during the preflight inspection and ensure that sufficient fuel was onboard for the flight, which resulted in a total loss of engine power due to fuel exhaustion.

NTSB analysis

The pilot reported that, a few minutes after takeoff for an agricultural application flight, while maneuvering to a field he intended to spray, the engine lost power and that he then attempted to land on a dirt road. He added that the airplane bounced on touchdown and "went off the road and struck a ditch." He further added that when the engine lost power, the fuel gauge indicated about half full. Postaccident, the pilot reported that the fuel gauge was "stuck in the middle," that he did not visually check the fuel quantity before flight, and that he had exhausted the fuel supply.

The fuselage and both wings sustained substantial damage.

The pilot reported that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation.

The Federal Aviation Administration Pilot's Handbook of Aeronautical Knowledge stated, in part:

Fuel Gauges

The fuel quantity gauges indicate the amount of fuel measured by a sensing unit in each fuel tank and is displayed in gallons or pounds. Aircraft certification rules require accuracy in fuel gauges only when they read "empty." Any reading other than "empty" should be verified. Do not depend solely on the accuracy of the fuel quantity gauges. Always visually check the fuel level in each tank during the preflight inspection, and then compare it with the corresponding fuel quantity indication.

Text from the NTSB. Open the NTSB docket for GAA17CA305 for the full record.