Cessna 195 N195JL accident near Ravensdale, Washington

Probable cause

Partial loss of power for undetermined reasons. Contributing to the accident was the siphoning of fuel from the left-wing fuel filler port due to wear on the fuel filler cap.

NTSB analysis

The pilot and a passenger departed with about 57 to 60 gallons of fuel on board. The pilot estimated that the flight would last about 2 hours and the fuel consumption rate would be about 18 to 21 gallons per hour; given the available fuel and consumption rate, the airplane should have had sufficient fuel for about 2.5 to 3.1 hours of flight. The pilot reported that while en route, there were indications of a fuel imbalance between the left and right fuel tanks while the fuel selector was positioned on BOTH, along with the smell of fuel. The pilot adjusted the fuel selectors until the fuel level was about equal in the left and right fuel tanks. About 15 minutes before reaching the destination, the engine sputtered and lost power but remained running near the idle setting of 600 rpm for the remainder of the flight. The pilot performed a forced landing to an off-airport site and impacted obstacles, which substantially damaged the fuselage, wings, and empennage. The pilot shut the engine down before exiting the airplane.

The total flight time was considerably less than the calculated fuel endurance. During the wreckage recovery, about 5 gallons of fuel was removed from the left-wing tank and about 3 gallons were removed from the right tank. The airplane’s unusable fuel was about 2.5 gallons per tank, which revealed that both tanks were very close to the unusable fuel quantity; however both tanks had usable fuel in them.

Postaccident examination revealed additional evidence of fuel escaping. The left wing exhibited a dirt and fuel residue that ran from the fuel filler port to the trailing edge of the wing, indicating that fuel siphoned out of the filler port during the accident flight. The left-wing filler port exhibited wear marks near the cap locking seat, which may have provided a loose fit between the cap to the seal. The right wing did not exhibit similar staining. The pilot found evidence of fuel leaking from the carburetor during his postaccident inspection and surmised that the carburetor bowls may have become lodged and did not meter the fuel in the bowl correctly. No other mechanical malfunctions or failures with the airframe or engine were observed that would have precluded normal operation. A test run of the engine revealed normal operations up to 2,200 rpm with no evidence of fuel leaks before , during or after the test run.

Text from the NTSB. Open the NTSB docket for WPR23LA294 for the full record.