History of Flight
On December 21, 2020, at about 1452 central standard time, an Express CT, N772BM, was involved in an accident near Grand Prairie, Texas. The private pilot and pilot-rated passenger sustained fatal injuries. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as a personal flight.
The pilot was instructed by the Grand Prairie Municipal Airport (GPM) ground controller to taxi to Runway 17. The pilot requested flight following to Denton Enterprise Airport (DTO). The local control (LC) controller cleared the airplane for takeoff on Runway 17, and the pilot requested a right turn, which was approved. The LC controller observed the airplane on the tower display workstation and noted it was heading toward Arlington Municipal Airport (GKY) airspace. The controller instructed the pilot to keep the turn “tight” to remain outside GKY’s airspace and to contact departure, but received no response.
A witness standing on the ramp saw the airplane take off from Runway 17. After takeoff, it entered a right crosswind and began a turn north for a right downwind departure. The witness reported that the air traffic control tower instructed the flight to “keep it tight” to avoid GKY airspace. The airplane’s bank angle increased significantly before it entered a steep dive. The witness heard the engine power up to what sounded like full power shortly after the dive began. The witness then lost sight of the airplane and saw a plume of smoke from the impact. The airplane struck a light pole, a road, and an automobile, after which a post-impact fire occurred.
Wreckage and Impact
The airplane came to rest upright and was destroyed by impact forces and a postcrash fire. A postaccident examination confirmed flight control continuity from the control surfaces to the cockpit controls. Engine valve and drive continuity was confirmed; cylinder compression was verified when the propeller was rotated by hand. A borescope examination of the engine cylinders revealed no abnormal features. The fuel injector screen and propeller governor oil screen were free of debris. Engine accessories were destroyed by fire and could not be tested.
Medical and Pathological Information
According to autopsy reports, the cause of death for both the pilot and pilot-rated passenger was blunt force injuries with thermal trauma due to the airplane crash, and the manner of death was accident. The pilot’s heart was enlarged (475 grams), but no other significant natural disease was identified. Toxicological testing detected diphenhydramine in the pilot’s cavity blood (68 ng/mL), heart blood (116 ng/mL), urine, and liver tissue. Pseudoephedrine was detected in cavity blood, heart blood (264 ng/mL), and urine. Dihydrocodeine was detected in urine at 12 ng/mL. For the pilot-rated passenger, toxicology testing detected diphenhydramine at 132 ng/mL in chest cavity blood; no significant natural disease was found.
Diphenhydramine, commonly marketed as Benadryl, is an over-the-counter antihistamine used for colds, allergies, and insomnia. It carries warnings about impairing mental and physical ability for hazardous tasks. The therapeutic range is 50 to 100 ng/mL, with a half-life of 3 to 14 hours. The FAA recommends a 60-hour post-dose observation time before flying after using this medication. Pseudoephedrine is generally non-impairing, and dihydrocodeine can cause drowsiness.