American Aviation AA-1A N6409L accident near Cleburne, Texas

Probable cause

The student pilot’s decision to operate the airplane after consuming alcohol, which led to an exceedance of the airplane’s critical angle of attack, an aerodynamic stall, and a subsequent loss of control at a low altitude.

NTSB analysis

The student pilot was returning to his home airport after making three stops to pick up and drop off equipment and a passenger. While the airplane was at low altitude about 5 miles from the student pilot’s home airport, the airplane made a left turn that was followed by a right turn near the airplane’s stall speed. The airplane rapidly descended and impacted a field in a nose-low attitude and with minimal forward momentum. The airplane came to rest upright, with both wings crushed downward and the engine partially separated and forward of the main wreckage. There was no evidence of preimpact mechanical malfunctions were observed during examinations of the engine and airframe.

Six empty mini-sized alcohol bottles were found in the airplane’s glove box. In addition, the pilot’s toxicology results showed ethanol concentrations that were about five times the Federal Aviation Administration regulatory limit of 0.04 gm/dL. At such concentrations, the pilot would likely have experienced degradation of judgment and deficits in coordination, psychomotor skills, perception, and attention.

The student pilot’s toxicology results indicated that he was drinking alcohol before the time of the accident. The student pilot’s decision to maneuver the airplane at a low altitude while under the influence of alcohol caused the airplane to exceed its critical angle of attack and enter a stall, resulting in a loss of control from which the student pilot could not recover.

Text from the NTSB. Open the NTSB docket for CEN22FA203 for the full record.