Beech F33A N17747 accident near Baton Rouge, Louisiana

Probable cause

The sudden and total loss of fuel flow to the engine for undetermined reasons.

NTSB analysis

The pilot and pilot-rated-passenger were conducting an instrument approach when there was a sudden and total loss of fuel flow to the engine as the airplane descended through 1,200 ft mean sea level (msl). The pilot was unable to restore engine power after he increased the throttle and mixture controls, checked both magnetos, and engaged the starter motor. Based on recorded engine data, there was no fuel flow to the engine for the remainder of the flight.

The pilot declared an emergency with the air traffic controller and made a forced landing in a grass area short of the runway. The airplane clipped trees and bounced during the forced landing. The fuselage and both wings were substantially damaged during the accident.

The engine examination revealed no evidence of a preimpact mechanical malfunction or failure that would have precluded normal operation. There was no evidence of a fuel leak inside the engine compartment or outside on the lower cowl and fuselage skins. The push-pull throttle, mixture, and propeller controls remained intact and functioned as designed. The airframe fuel filter and the inlet screen to the throttle and control unit remained wet with fuel and were free of particulate contamination. Fuel was found in the return lines. Additional examination and testing of the throttle and control unit, engine-driven fuel pump, fuel distribution valve, and fuel flow transducer did not reveal any anomalies that would have resulted in a sudden and total loss of fuel flow to the engine during the flight.

The postaccident examination revealed usable fuel in each wing tank. Although the fuel selector was found in the OFF position, it could have been repositioned by the pilot or first responders to secure the airplane’s fuel system after the accident. Additional review of the recorded engine data did not reveal erratic engine operation that is typically associated with a loss of engine power due to fuel starvation or exhaustion.

Alternatively, if the pilot or pilot-rated-passenger inadvertently repositioned the mixture control to cutoff during the descent, it would have resulted in the sudden and total loss of fuel flow that was recorded by the engine monitor. However, based on the pilot’s statement, he attempted to restore engine power by increasing the throttle and mixture controls. With a windmilling propeller, the engine-driven fuel pump would have provided appreciable fuel flow to the engine if the mixture control was forward of the cutoff position.

The reason for the sudden and total loss of fuel flow to the engine could not be determined.

Text from the NTSB. Open the NTSB docket for CEN22LA391 for the full record.