Airborne Classic N582YA accident near Stow, Massachusetts

Probable cause

The operator's inadequate engine maintenance, which resulted in a total loss of engine power. Contributing to the accident was the pilot's decision to conduct a downwind takeoff.

NTSB analysis

After performing a preflight inspection, the pilot taxied, completed an engine magneto check, took off, flew around the traffic pattern, and landed. Shortly thereafter, a passenger got into the back seat, and the pilot took off with a 5- to 10-knot tailwind. A witness heard a “funny metallic sound” before the engine sustained a complete loss of power a few seconds later. The aircraft then glided for 5 to 10 seconds before it turned sharply to the left in what appeared to be an attempt to do a 180-degree turn to land back on the runway. The aircraft then turned again sharply to the left, dived at an approximate 45-degree angle toward the displaced threshold of the runway, and impacted the ground. Postaccident examination of the engine revealed that it had sustained a cold seizure, which is indicative that the engine had been running with too lean of a fuel/air mixture before the accident. (A cold seizure occurs when the piston expands faster than the cylinder and the clearance between the piston and cylinder is reduced.)The maintenance records contained no entries related to such items as carburetor readjustments and checks that were required by the engine manufacturer to be accomplished as part of the maintenance schedule. Further examination of the maintenance records revealed that the engine had previously suffered a cold seizure and a broken piston ring. Also, 2 months before the accident, the cylinder heads were replaced with cylinder heads of an older design that had accumulated 125 hours of operation, but the gearbox and carburetors were reused. The engine then accrued another 4 hours of operation prior to the final cold seizure that preceded the accident. The airport was surrounded by wooded terrain and water. Departing with a tailwind increases an aircraft’s takeoff roll and decreases its climb angle, resulting in less altitude gain over distance traveled. Thus, the pilot’s decision to depart with a tailwind reduced his remedial options available following the loss of engine power because the aircraft was at a lower altitude over unsuitable landing terrain and farther from the runway than it would have been if the pilot had departed into a headwind.

Text from the NTSB. Open the NTSB docket for ERA11LA049 for the full record.