Cessna 152 N95550 accident near Everglades City, Florida

Probable cause

The loose nut connecting the mixture control cable to the mixture control arm, which resulted in the pilot’s inability to control the mixture and the subsequent total loss of engine power.

NTSB analysis

The pilot reported that while in level cruise flight on the personal flight, he adjusted the throttle and mixture controls. Shortly after, the engine lost total power. Emergency engine procedures did not restore engine power, and the pilot selected a nearby airport for a forced landing. During the subsequent emergency landing, the airplane struck a perimeter fence before impacting the ground just short of the runway, which resulted in substantial damage to the fuselage. A postaccident engine examination revealed that when the mixture control was manipulated, the cable moved, but the mixture arm on the carburetor did not move. When the fiber lock nut that attached the mixture cable to the mixture arm was tightened, the mixture linkage operated normally. The engine was then started and operated at various power settings. Given the absence of mechanical issues other than the loose mixture control fiber lock nut, it is likely that the mixture linkage became loose and the mixture control arm vibrated to the lean direction, which resulted in the mixture being too lean and the engine losing total power.

Text from the NTSB. Open the NTSB docket for ERA18LA050 for the full record.