ERA23LA035 · Beech V35A

The pilot departed for a local flight to practice instrument approaches, and after completing two approaches to a nearby airport, was returning to the departure airport. While maneuvering to enter the airport traffic pattern the engine suddenly lost power completely. The pilot attempted to troubleshoot the loss of engine power by switching fuel tanks and adjusting the engine controls, but was not successful. He subsequently ditched the airplane into a river and the airframe was substantially damaged during the landing. Postaccident examination of the airplane revealed that the intact fuel tanks each contained a quantity of fuel less than their unusable capacity. Additionally, downstream components of the fuel system contained only trace amounts of fuel. Examination of the engine and airframe revealed no evidence of any mechanical malfunction or failure that would have precluded normal operation. Data recovered from an engine data monitor revealed that, about 1 hour into the flight, the exhaust gas temperature (EGT) of all the engine’s cylinders suddenly increased before then rapidly decreasing, consistent with the sudden loss of engine power described by the pilot. The sudden increase of EGT that preceded the rapid decrease is consistent with a leaning of the engine’s fuel mixture (consistent with what would occur following an interruption or exhaustion of the available fuel supply). Given the lack of fuel found during the postaccident examinations of the airplane, and based on the engine monitor data, it is likely that the pilot misjudged the amount of fuel onboard the airplane before departing on the accident flight, which resulted in fuel exhaustion and a total loss of engine power.

Verbatim NTSB analysis and probable cause from the NTSB dataset