Luscombe 8A N71823 accident near Schaumburg, Illinois

Probable cause

The pilot did not maintain airspeed following a loss of engine power during takeoff climb, which resulted in an aerodynamic stall. Contributing to the accident was the loss of engine power due to the unlocked engine primer.

NTSB analysis

A witness reported seeing the airplane takeoff and climb to about 150 feet above the ground. At that point, the sound from the engine ceased, and the airplane stalled and spun to the left making one-half revolution before striking the ground. Examination of the airframe, control system, and engine revealed no evidence of any preimpact mechanical anomalies that would have precluded normal operation. Examination of the cockpit engine controls showed that the carburetor heat was off and the engine primer was unlocked and pulled out. Although the weather conditions at the time of the accident were conducive to carburetor icing, they were not in the range likely to result in serious carburetor icing. Examination of the spark plugs indicated a rich mixture condition. The primer position and the condition of the spark plugs indicate that the engine power loss was likely due to an overly rich mixture resulting from excess fuel being pulled through the primer into the engine’s intake system when takeoff power was applied. Since the purpose of the primer is to assist in starting a cold engine, it is possible the pilot used the primer when starting the engine and did not ensure that it was in and locked before initiating take off.

Text from the NTSB. Open the NTSB docket for CEN11LA049 for the full record.