History of the Flight
On April 19, 2021, at approximately 1346 central daylight time, a Cessna 340A airplane, registration N801EC, was destroyed in an accident near Tatum, Texas. The pilot, who was the sole occupant, sustained fatal injuries. The flight was conducted as a Title 14 Code of Federal Regulations Part 91 test flight.
According to a fixed-base operator (FBO) at East Texas Regional Airport (GGG) in Longview, Texas, the pilot intended to perform a functional test of a newly upgraded autopilot system. On the day of the accident, a mechanic at the FBO reported pulling the airplane out of the hangar. The pilot planned to obtain fuel and have the propellers balanced before the flight. The mechanic advised the pilot not to engage the autopilot until reaching an altitude of at least 5,000 ft above ground level, a standard procedure for autopilot testing.
The pilot started the engines and the airplane sat on the ramp for about 15 minutes. The pilot then shut down the engines and informed the mechanic that the autopilot would not work. The mechanic showed the pilot the locations of the main autopilot and trim master switches and demonstrated that the autopilot passed a self-test. The mechanic instructed the pilot to attempt another self-test with the engines running and, if it failed, to shut down. The pilot ran the engines for 5 to 10 minutes and then departed.
Air traffic control (ATC) cleared the pilot to operate under visual flight rules east of the airport. Communications between ground control, tower control, and the pilot were normal during taxi, takeoff, and climb. Automatic dependent surveillance–broadcast (ADS-B) data showed the airplane took off from runway 13 at GGG about 1340. After takeoff, the airplane climbed steadily east of GGG, reaching an altitude of 2,750 ft mean sea level (msl) before descending to 2,675 ft msl. The last recorded data point, at 1346, showed the airplane heading east at 2,675 ft msl with a groundspeed of 152 knots. The airplane then impacted wooded terrain about 3/4 mile east of that point. Groundspeeds and headings were consistent with no abrupt deviations. Radio and radar communications were lost 6 minutes after takeoff, and no distress calls were received.
A local resident approximately 1 mile from the accident site reported hearing and feeling a "boom" that shook windows; his wife observed black smoke rising immediately.
Wreckage and Impact Information
The accident site was at an elevation of 361 ft msl. The airplane impacted wooded terrain in a nose-down, near-vertical attitude. The forward fuselage and cabin were embedded in the ground and mostly consumed by a postimpact fire. The empennage and aft fuselage were folded forward over the cabin area and were charred and consumed. Both left and right wings exhibited leading-edge aft crushing along their spans, with portions charred, melted, and consumed by fire.
Both engine nacelles separated from the wings, and the engine and propeller assemblies were embedded in craters about 3 ft deep forward of the main wreckage. The engines sustained heavy impact damage, and the propellers fractured and separated at their crankshafts immediately aft of the flanges. All three blades on each propeller were bent aft, with leading-edge polishing and chordwise rubs and scratches.
Flight control continuity was confirmed. The elevator trim cable stop blocks were secured and undamaged; they were found against the forward stop, indicating the trim tab was at full down travel (elevator leading edge full down), which meant the airplane was trimmed full nose-up at impact.
The instrument panel, avionics, autopilot, and engine controls were broken out, fragmented, melted, and consumed by the postimpact fire. Avionics and instrument tubing and wiring behind the panel were melted and consumed. A functional test of the autopilot system could not be performed due to the damage.
Examination of the engines revealed no preaccident failures or malfunctions that would have precluded normal operation.