Cessna 172N N734BY accident near Padre Island, Texas

Probable cause

The loss of engine power for reasons that could not be determined based on the available evidence.

NTSB analysis

The pilot reported that, during cruise flight, the engine lost power and began running roughly. He applied carburetor heat, set the mixture control to full rich, attempted to switch fuel tanks, and cycled the ignition switch to test the magnetos, but the engine continued to run roughly at reduced power. During the subsequent forced landing, the tires sunk into soft soil, and the airplane then nosed over.

The weather conditions when the power loss occurred were conducive to the accumulation of moderate carburetor icing at cruise and descent power settings. Formation of ice within the carburetor throat could have resulted in a richer fuel/air mixture that could have been further exacerbated by the pilot's application of carburetor heat and his setting of the mixture control to full rich. The airplane was recovered from the accident site and released before a postaccident examination could be conducted; therefore, other possible causes for the engine power loss could not be ruled out.

Text from the NTSB. Open the NTSB docket for CEN14LA276 for the full record.