Cessna T188 N2690J accident near Dustin, Oklahoma

Probable cause

The pilot’s continued takeoff without ensuring obstacles could be avoided due to his use of a sedating medication, which likely diminished his reaction time and flying performance.

NTSB analysis

The pilot was conducting his second aerial application flight of the day. According to a witness, the airplane had been topped off with fuel before the first flight and 165 gallons of chemical just before the accident flight. The witness stated that the airplane became airborne later than he expected. After departure, the airplane angled left from the runway heading and its wingtip impacted a power pole. It then hit power lines and another pole before coming to rest inverted in a draw.

A postaccident examination found no mechanical malfunctions or anomalies that would have precluded normal operation.

Toxicology testing indicated the pilot had the sedating antihistamine diphenhydramine in his blood at the time of the accident. The levels detected were above the therapeutic level for diphenhydramine. Given the pilot’s years of experience and familiarity with the aircraft, it is reasonable to consider that his reaction time and flying performance were diminished due to the use of sedating medication, which resulted in the impact with the power pole.

Text from the NTSB. Open the NTSB docket for CEN20LA271 for the full record.