Cessna A185F N7574N accident near Kingsley, Iowa

Probable cause

The total loss of engine power due to fuel exhaustion as a result of an unsecured fuel bladder, which reduced the fuel capacity of the affected tank.

NTSB analysis

The pilot reported that before departing on a cross-country flight, he added 42 gallons of 100LL aviation fuel, which appeared to fill both inboard wing fuel tanks. He calculated a 17-gallon-per-hour fuel burn for the 2 hour and 45-minute flight. While in cruise flight, about 2.5 hours after departure, a total loss of engine power occurred. The pilot was unable to restart the engine, and he executed a forced landing to a corn field, which resulted in substantial damage to the fuselage and right wing.

Postaccident examination revealed that both left and right fuel tanks were intact. The fuel filler necks and collars were removed from both wings for internal inspection of the rubberized, bladder fuel cells. The cell from the left tank exhibited minor wrinkling, but overall was still attached to the cell’s snaps and fittings. When the right cell was examined, it was discovered to be unsecured from the outboard and aft edges with the cell folded and wrinkled inboard to the outboard fuel filler neck.

The investigation was unable to determine the extent to which the loose fuel cell bladders would have affected actual fuel quantity and unusable fuel. However, given the lack of malfunctions or anomalies noted during the examination and the lack of fuel present in the gascolator, it is likely that the engine lost power due to fuel exhaustion.

Text from the NTSB. Open the NTSB docket for CEN21LA406 for the full record.