History of Flight
On February 2, 2021, at 1744 central standard time, a Cessna 182Q airplane, registration N4765N, was destroyed when it impacted terrain near Hackberry, Louisiana. The private pilot and a flight instructor were fatally injured. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as an instructional flight.
According to recorded air traffic control (ATC) communications and automatic dependent surveillance–broadcast (ADS-B) data, the airplane departed at 1713 and proceeded south toward the Gulf coast. Shortly after takeoff, the pilots contacted ATC and reported their intention to operate in the southwest practice area. At about 1725, ATC instructed the pilots to remain at or above 2,500 ft above ground level (agl) for traffic. The pilot acknowledged the restriction and mentioned that a maneuver might cause a loss of altitude at their current position.
ADS-B data showed the airplane completed several circling maneuvers near the coast and descended toward an old airstrip. At 1736, the pilot advised that they were climbing back to 2,500 ft agl or above. ATC asked if they needed to descend below the restriction, and the pilot responded that they did not until returning to Southland Field Airport (UXL) in Sulphur, Louisiana.
The airplane then proceeded north, and altitude and airspeed increased. As it reached about 4,500 ft agl, airspeed decreased, and the airplane began a slow descent before entering a rapid descent. In the last 18 seconds of recorded data, the airplane made a right turn and descended at a rate of about 11,250 ft per minute. At 1745, radar contact was lost, and no further radio transmissions were received.
Two witnesses in close proximity to the accident site, though at different locations, stated that they saw the airplane come straight down, nose first to the ground. One witness reported no smoke from the airplane and never saw the cockpit. Both witnesses described the engine as loud.
Personnel Information
According to a co-owner of the airplane, the private pilot had recently purchased a share of the accident airplane and was receiving training for complex and high-performance aircraft endorsements. The day before the accident, one co-owner was in the back seat during a training flight with the same pilot and flight instructor. He stated that the pilot completed maneuvers well and he noticed nothing of concern.
According to the airplane broker, on the day of the accident, the pilot reported completing a 1-hour flight in the accident airplane to satisfy insurance policy requirements. That flight departed from Southland Field Airport (UXL) at about 1326 and terminated at about 1436.
Aircraft Information
The airplane was equipped with a Garmin GFC500 automatic flight control system (AFCS) autopilot, which featured electronic stability and protection (ESP). According to the Garmin AFCS manual, ESP provides a soft barrier to keep the airplane within the desired operating envelope when the autopilot is not engaged. When the AFCS senses the airplane is near defining limits in pitch attitude, roll attitude, high airspeed, or low airspeed, ESP automatically engages one or more servos to nudge it back to the nominal operating envelope. ESP uses the same sensors, processors, and actuators as the AFCS autopilot but is a separate, mutually exclusive function. ESP can be easily overpowered by the pilot and disabled using the autopilot disconnect button. It is intended to monitor the airplane and provide control input feedback to discourage operating at potentially unsafe attitudes and airspeeds.
The GFC500 manual also states that level mode as activated by ESP is limited by altitude. ESP cannot activate level mode until the airplane climbs above 2,000 ft agl and will be locked out from automatically activating level mode after descending below 1,500 ft agl. Manually-selected level mode is not altitude-limited.
ESP is enabled or disabled from the primary flight display (PFD) page menu, and the Garmin website states that ESP can be manually disabled to allow for intentional flight maneuvers.
According to one of the other airplane owners, during practice stall maneuvers, the autopilot circuit breaker needed to be pulled to complete the maneuver. He stated that even if the autopilot is not engaged, this autopilot safety feature remains in effect unless the circuit breaker is pulled. He added that it might be possible to stall the airplane without pulling the circuit breaker, but “you would be really fighting the servos in the auto pilot.” On the day before the accident, when he was a passenger in the back of the airplane, he observed the accident pilots pull the autopilot circuit breaker before completing maneuvers.
Wreckage and Impact Information
The airplane impacted soft, muddy terrain. The initial impact crater was about 15 ft deep and contained the majority of the airplane, including the engine, propeller, fuselage, and empennage. A debris field containing the wings and smaller components extended about 40 yards from the crater.
The wreckage was recovered to a secure storage facility, where an engine and airframe examination was completed under the supervision of a Federal Aviation Administration inspector. The wings had separated from the fuselage and were crushed aft to the rear wing spar. The empennage was crushed and distorted. Flight control cable continuity was established for all flight control surfaces through tensile overload separations in several locations. The fuel selector valve was found in the “both” position. The engine sustained significant impact damage and was saturated with mud. The crankshaft sheared aft of the propeller flange. Two propeller blades remained attached to the hub and exhibited S-bending and curling. The crankshaft could not rotate due to impact damage. The examination was limited due to extensive impact damage but did not reveal any preimpact anomalies.
Medical and Pathological Information
An autopsy of the pilot performed by the Calcasieu Parish Coroner's Office listed the cause of death as multiple injuries sustained in an airplane crash. The brain was not available for examination due to the severity of injuries. An internal examination found no significant natural disease. Toxicology testing of the pilot’s heart tissue by the FAA’s Forensic Sciences Laboratory identified no evidence of impairing drugs.
An autopsy of the flight instructor performed by the same office listed the cause of death as multiple injuries sustained in an airplane crash. The autopsy was limited to an external examination only. A cursory internal examination of the organs did not identify any natural disease. Toxicology testing for the flight instructor was not possible because no suitable specimens were available.