Cessna 182 N4092D accident near Pottstown, Pennsylvania

Probable cause

The pilot's failure to ensure that sufficient fuel was onboard for nonlevel flight, which resulted in a total loss of engine power due to fuel starvation.

NTSB analysis

During cruise flight, the airplane’s engine lost total power, which resulted in the pilot making an off-field emergency landing on a highway. During the landing, the airplane struck two automobiles and was substantially damaged.

After the accident, when the wings were removed for transport, 4 to 6 gallons of fuel were drained from the left-wing tank, and the right-wing tank was empty. Except for some fuel damping on the left-wing fuel tank feed hose and fuel staining, both of which were consistent with removal of the wing, no anomalies were noted during the examination of the fuel system. A test run of the engine was accomplished with no anomalies noted. Examination of the engine and data from the installed engine data monitor did not reveal evidence of any preimpact failures or malfunctions of the engine that would have precluded normal operation.

Review of the airplane owner’s manual indicated that fuel was supplied to the engine from two rubberized bladder type fuel cells (fuel tanks). Each fuel cell had a single fuel line located in the aft inboard section of the fuel cell. Fuel flowed via gravity from each of these fuel lines through the fuel selector valve and fuel strainer to the carburetor. The manual stated that 1.5 gallons of fuel per fuel tank were unusable and that, when not in level flight, an additional 3.5 gallons of fuel per fuel tank were unusable. This information (the location of the fuel lines in the aft inboard sections of the fuel tanks and the additional unusable fuel when not in level flight) indicated that the engine was susceptible to fuel starvation if the airplane was in a nose-low attitude with insufficient fuel in the fuel tanks.

According to the chief pilot of the skydiving company that used the airplane for its skydiving operations, the pilot told him that when the engine lost power, the airplane was in a nose low attitude and that the engine was “surging” (losing and regaining power). The chief pilot stated that “surging is a characteristic of fuel starvation as the fuel is being unported and then recovered as the fuel sloshes around in the tank.” The chief pilot expressed the opinion that if the pilot had “pitched the aircraft up to level flight the engine would have had enough fuel to [reach] the nearest airport about 7 miles away.”

Given that the amount of fuel recovered from the airplane (4 to 6 gallons) was less than the total unusable fuel when not in level flight (10 gallons) and that the engine operated with no discrepancies following the accident, it is likely that the loss of engine power occurred when the pilot flew the airplane in a nose low attitude with little fuel onboard, which resulted in fuel starvation.

Text from the NTSB. Open the NTSB docket for ERA20LA258 for the full record.