Cessna 172 N172XX accident near Decatur, Georgia

Probable cause

Oil exhaustion due to an oil leak that resulted in a total loss of engine power.

NTSB analysis

The student pilot reported that, before takeoff, he added 1 quart of oil, bringing the oil quantity to full capacity. Shortly after takeoff, while the airplane was at an altitude of 1,500 ft mean sea level, the pilot noted that the engine began running roughly, which was followed by a total loss of engine power. He pitched the airplane to attain its best glide airspeed. He descended the airplane for a forced landing to a four-lane road, during which the airplane struck powerlines and came to rest inverted on the road.

Postaccident examination of the engine found that crankcase was breached consistent with a catastrophic failure. Additionally, a substantial amount of oil was covering the exterior of the bottom fuselage skin from the engine compartment to the tailcone, fresh oil was noted in the cockpit floor area, and only a minimal amount of oil remained in the engine. Given this information it is most likely that the total loss of engine power occurred due to oil exhaustion, that was precipitated by an oil leak. At the rear portion of the engine, the oil filter adapter and its attached base had separated from the accessory case. Although it is possible that the oil leak emanated from this location, the available evidence for this investigation precluded a definitive determination of the source for the oil leak.

Text from the NTSB. Open the NTSB docket for ERA22LA045 for the full record.