Waco YMF-F5C N30AB accident near Austin, Texas

Probable cause

A total loss of engine power for undetermined reasons.

NTSB analysis

**This report was modified on August 4, 2021. Please see the public docket for this accident to view the original report.**

The airline transport pilot departed on an aerial observation tour flight with two passengers. About 25 minutes into the flight, the engine experienced a total loss of power while overflying a lake. One of the passengers stated that it sounded like the pilot was trying to get the engine "going" multiple times and that the engine sounded like a motorcycle or lawnmower when it was running out of fuel. The pilot ditched the airplane about 100 yards from the shore, and the airplane nosed over during the ditching. All occupants egressed and were assisted by boaters in the area.

The airplane's total usable fuel quantity was 72 gallons, with 24 gallons usable in each of the two main wing fuel tanks, and 12 gallons usable in each of the two auxiliary fuel tanks. The left fuel selector handle controlled the fuel flow from the left tanks, and the right fuel selector controlled the flow from the right tanks. Postaccident observations of the wreckage revealed the right fuel selector handle was in the OFF position, and the left fuel selector was in the ON position; however, it is unknown whether the right fuel selector handle was moved to the OFF position before the loss of engine power or after the accident occurred during egress or removal of personal items.

The airplane was last fueled five days before the accident, at which time all of the tanks were "topped off." Subsequent flight and ground operations on the days before the accident flight burned about 32.5 gallons of fuel. Given the airplane's fuel burn was about 15 gallons per hour, the airplane would have consumed about 6 gallons during the accident flight before the loss of engine power. It is likely that the airplane had been flown only on the left tanks on the days before and the day of the accident flight, burning all of the usable fuel in the left tanks, despite available fuel in the right tanks.

The pilot reported that he used the airplane's electronic engine monitor and visual sight gauges to determine the fuel on board during the accident preflight inspection. The airplane had sufficient fuel onboard to complete the flight; however, a postaccident examination of the engine and fuel system was not completed. Therefore, the reason for the loss of engine power could not be determined based on the available information.

Text from the NTSB. Open the NTSB docket for CEN16LA254 for the full record.