Cessna 172 N5276U accident near Apalachicola, Florida

Probable cause

A total loss of engine power for reasons that could not be determined during postaccident examination and testing.

NTSB analysis

The commercial pilot reported that the accident flight was the first flight since maintenance was performed after water was found in the fuel system. The pilot performed a preflight, sumped the fuel tanks with no water noted, and conducted an engine run-up with no anomalies noted. After takeoff, the pilot performed one circuit in the traffic pattern, and, during the final approach, he chose to perform a go-around. He applied full throttle, and the airplane began to climb, but the engine then lost total power. He subsequently turned the fuel pump on, applied carburetor heat, and began to "pump" the throttle. The engine started but then lost total power again. The pilot restarted the engine two more times, but, after it lost power again, he chose to perform a forced landing to a marsh, which resulted in substantial damage to the fuselage.

A postaccident examination of the engine confirmed engine continuity from the propeller flange to the engine's accessory section, and an engine test run was performed with no anomalies noted. The left tank fuel line to the engine was found partially blocked with "fresh" sealant-type material. However, a review of the maintenance records found no entries indicating when the sealant was applied to the fuel tank. The fuel selector was found in the "both" position. Given that the sealant was only partially blocking the fuel line and that both fuel tanks were feeding the engine, the blockage likely would not have affected the engine power.

Although the weather conditions were conducive to the accumulation of serious carburetor icing at glide power at the time of the accident and the total loss of engine power occurred after the engine had been operating at a low-power setting for the descent on final approach, the investigation could not determine whether carburetor ice caused the total loss of engine power.

Text from the NTSB. Open the NTSB docket for ERA14LA374 for the full record.