Cessna 152 N49811 accident near Palo Alto, California

Probable cause

Loss of engine power during the takeoff initial climb due to lack of compression to a cylinder.

NTSB analysis

Prior to the accident flight, a maintenance inspection was performed. A piece of the baffling was found in the throat of the carburetor venturi. The carburetor was inspected and reinstalled on the airplane. On the accident flight, the pilot/mechanic performed a post maintenance run-up with no mechanical problems noted. She taxied the airplane to the runway for takeoff and performed another run-up. Again there were no mechanical problems noted, and all the gages showed normal indications. On the takeoff roll the engine developed 2,300 rpm’s. About 500 feet mean sea level (msl), she noticed a hesitation in the engine and decided to make a 180-degree turn back to the runway. The airplane was still high on the approach, so the pilot reduced the airspeed, performed S-turns, and then slipped the airplane to lose altitude. She was still high, and about halfway down the runway, she further reduced the airspeed, which increased the sink rate. She lowered the nose to slow the sink rate, and was in the process of raising the nose again to flare for landing when the nose struck the runway. An inspection of the engine revealed zero compression of the number 1 cylinder with blow-by past the piston rings and exhaust valve. Maintenance personnel also noted that the bottom number 1 cylinder spark plug was "excessively" fouled with carbon deposits. There were no problems noted with the carburetor.

Text from the NTSB. Open the NTSB docket for LAX08LA055 for the full record.