History of Flight
On July 28, 2019, at about 1609 central daylight time, a Piper PA-34, registration N456AG, was destroyed in an accident near Gainesville, Texas. The aircraft was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. The flight instructor and the pilot receiving instruction sustained fatal injuries.
According to Automatic Dependent Surveillance-Broadcast (ADS-B) data, the airplane departed Denton Enterprise Airport (DTO) in Denton, Texas, at 1440. It flew two visual approaches at DTO, then climbed to the northwest and maneuvered between 4,000 and 5,000 feet mean sea level. The airplane then descended toward Gainesville Municipal Airport (GLE) from the west, entered a left downwind for Runway 18, and completed several takeoffs and landings. The last recorded ADS-B data showed the airplane about 3,200 feet north of the Runway 18 threshold at 75 knots ground speed and about 250 feet above ground level. The airplane subsequently impacted the ground about 1,500 feet left of Runway 18. A post-impact fire ensued.
Personnel Information
The pilot receiving instruction had failed the training company's Stage 1 flight check for his commercial rating twice before the accident flight. Company records indicated the pilot struggled with basic aircraft control and had a lack of situational awareness. During both flight checks, the pilot did not maintain positive control of the airplane during simulated engine failures in the traffic pattern.
English was not the pilot's native language, and according to a flight instructor, the pilot was not a proficient English speaker. Another flight instructor reported that, during a flight, the pilot continued to apply pressure on the rudder pedals after being verbally directed to relinquish the flight controls; a forceful command was required to correct the deficient transfer of control.
The company submitted a request to the pilot's sponsoring airline for five additional hours of training to address deficiencies. However, according to the company director of training, the submission was delayed because it "fell between the cracks." The pilot did not fly for about five weeks, but practiced solo in an aviation training device (ATD) 26 times between June 14 and July 24, 2019, and once each on July 26 and 27, 2019. The pilot's last flight before the accident occurred on July 25, 2019, with the accident flight instructor. Company training records for that flight indicated the pilot required constant reminders to maintain heading during all maneuvers, especially engine-out maneuvers.
The flight instructor was hired by the company on November 29, 2018, and completed an instructor proficiency check for the PA-34-200 on March 1, 2019. According to the company chief pilot, the flight instructor completed a proficiency check to be a company check airman in single-engine airplanes.
Aircraft Information
The airplane's engines were both replaced on July 12, 2019, with overhauled units following a propeller strike incident. At the time of the accident, each engine had accumulated about 22 hours of flight time.
On July 24, 2019, an instructor reported a power loss on the right engine during taxi. After restarting the right engine and pulling the throttle to idle, a second power loss occurred. Maintenance adjusted the right engine to a higher idle speed, and the flight was aborted. Later that day, another instructor flew the airplane and observed the left engine sputter and lose power about 2 to 3 seconds after landing at GLE. The instructor restarted the left engine on the fourth attempt and returned to DTO uneventfully. A mechanic conducted an engine run from idle to full power with rapid throttle movements; no anomalies were noted, and the airplane was returned to service.
On July 25, 2019, the accident flight instructor flew the airplane and reported that after landing, the left engine lost power on the runway after idling, but was restarted on the taxiway. A mechanic increased the left engine idle power setting as a corrective action; this maintenance action was not recorded in the engine maintenance log.
During engine runup at DTO immediately before the accident flight, a witness heard an abnormal noise similar to a rough running engine. The witness then noticed the left engine was shut down and restarted. The airplane departed and flew two visual approaches without abnormal noises.
Wreckage and Impact Information
The airplane impacted a mowed field in a left-wing-low attitude, with the debris path oriented to the northeast. The fuselage was consumed by fire from the forward bulkhead to the aft tail cone. Flight control cable continuity was established from the cockpit to each control surface. The main landing gear was retracted, and the flap position could not be determined. Cockpit switches and fuel selector levers provided no usable information due to fire damage. The left and right wing fuel selector valves were in the on position. The stabilator trim jackscrew corresponded to a partial nose-up setting, and the rudder trim jackscrew corresponded to a partial right rudder trim tab deflection.
Both propellers remained attached to their crankshaft flanges. The left propeller blades were at a low pitch setting with no scoring on the blade faces. The right propeller blades were at an intermediate pitch setting with leading edge polishing and chordwise scoring on the blade faces. Crankshaft, camshaft, and valve train continuity was confirmed for both engines. Both engine ignition harnesses and magnetos were significantly fire damaged. The fuel inlet screens of both engines were free of debris. The left engine No. 2 cylinder fuel injector nozzle was plugged with an unknown substance; the remaining left engine and all right engine fuel injector nozzles were clear.
Medical and Pathological Information
Toxicology tests performed on the flight instructor were positive for medications used in resuscitative efforts after the accident, including ketamine, norketamine, midazolam, lorazepam, morphine, fentanyl, norfentanyl, and etomidate. Toxicology tests performed on the pilot receiving instruction were positive for carboxyhemoglobin, consistent with exposure to post-accident fire.
Organizational and Management Information
Most flight instructors stated there was no pressure from the company to take a flight, but there was pressure for students to complete training within the allotted curriculum hours. Some student pilots felt pressure to fly and believed flight instructors also felt pressure to fly an unsafe aircraft. Several flight instructors noted the school was short on airplanes and multi-engine flight instructors. The company director of training stated that "there obviously is pressure … to give the student training" and that flight instructors might feel pressure when only a few aircraft are available. He viewed these pressures as internal, noting that instructors might also feel pressure because pay was based on flight hours and they wanted to log flight hours.