N4765NCessna 182Q · 1979

On February 2, 2021, at 1744 central standard time, a Cessna 182Q airplane, N4765N, was destroyed when it was involved in an accident near Hackberry, Louisiana. The private pilot and flight instructor were fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight.

Recorded air traffic control (ATC) communications and automatic dependent surveillance–broadcast (ADS-B) data revealed that the airplane departed at 1713 and proceeded south toward the Gulf coast. Soon after takeoff, the pilots contacted ATC and reported their intentions to operate in the southwest practice area. About 1725, the pilots were instructed to remain at or above 2,500 ft above ground level (agl) for traffic. The pilot acknowledged the restriction and advised that his maneuver might cause a loss of altitude at their current position. ADS-B data showed that 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 queried if they needed to descend below the restriction, and the pilot responded that they did not, until they returned to Southland Field Airport (UXL), Sulphur, Louisiana.

The airplane proceeded north, and the altitude and airspeed increased. As the airplane reached about 4,500 ft agl, the airspeed decreased, and the airplane began to slowly descend before entering a rapid descent until the final recorded point. 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. Figure 1 shows the end of the recorded flight track and the accident location. At 1745, radar contact was lost; no further radio transmissions were received from the accident airplane.

Figure 1. The recorded flight track and accident location overlayed on Google Earth.

Two witnesses, who were in close proximity to the accident site but at different locations, stated that they observed the airplane come straight down, nose first to the ground. One witness reported that no smoke was coming from the airplane, and he never saw the cockpit. Both witnesses reported the engine was loud.

According to a co-owner of the airplane, the private pilot had recently purchased a share of the accident airplane and was in the process of receiving training for complex and high-performance aircraft endorsements. The day before the accident, one of the co-owners was in the back seat of the airplane when the two accidents pilots conducted a training flight. He stated that the pilot completed the flight maneuvers well and he did not notice anything of concern.

According to the airplane broker, on the day of the accident, the pilot called to report that he had just completed a 1-hour flight in the accident airplane to satisfy the insurance policy requirements. That flight departed from Southland Field Airport (UXL), Sulphur, Louisiana, about 1326 and terminated about 1436.

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, the ESP function provides a soft barrier to keep the airplane within the desired operating envelope when the autopilot is not engaged. When the AFCS senses that the airplane is near the defined operating limit in pitch attitude, roll attitude, high airspeed, or low airspeed, the ESP function will automatically engage one or more servos to nudge it back to the nominal operating envelope. While ESP utilizes the same sensors, processors, and actuators as the AFCS autopilot, it is a separate, mutually exclusive function. ESP can be easily overpowered by the pilot and can be disabled using the autopilot disconnect button. ESP is a feature that is intended to monitor the airplane and provide control input feedback when necessary to discourage operating the airplane at potentially unsafe attitudes and/or airspeeds.

The GFC500 manual also states that level mode as activated by ESP is limited by altitude. ESP will not be able to activate level mode until the airplane climbs above 2,000 ft agl. ESP will be locked out of automatically activating level mode after the airplane descends below 1,500 ft agl. Also, level mode as activated by ESP is different than manually-selected level mode. Manually-selected level mode is not limited by altitude.

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 in order to complete the maneuver. He added that, even if the auto pilot is not engaged, this autopilot safety feature is still in effect unless the circuit breaker is pulled. He stated 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 passenger in the back of the airplane, he observed the accident pilots pull the autopilot circuit breaker before completing maneuvers.

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, the ESP function provides a soft barrier to keep the airplane within the desired operating envelope when the autopilot is not engaged. When the AFCS senses that the airplane is near the defined operating limit in pitch attitude, roll attitude, high airspeed, or low airspeed, the ESP function will automatically engage one or more servos to nudge it back to the nominal operating envelope. While ESP utilizes the same sensors, processors, and actuators as the AFCS autopilot, it is a separate, mutually exclusive function. ESP can be easily overpowered by the pilot and can be disabled using the autopilot disconnect button. ESP is a feature that is intended to monitor the airplane and provide control input feedback when necessary to discourage operating the airplane at potentially unsafe attitudes and/or airspeeds.

The GFC500 manual also states that level mode as activated by ESP is limited by altitude. ESP will not be able to activate level mode until the airplane climbs above 2,000 ft agl. ESP will be locked out of automatically activating level mode after the airplane descends below 1,500 ft agl. Also, level mode as activated by ESP is different than manually-selected level mode. Manually-selected level mode is not limited by altitude.

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 in order to complete the maneuver. He added that, even if the auto pilot is not engaged, this autopilot safety feature is still in effect unless the circuit breaker is pulled. He stated 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 passenger in the back of the airplane, he observed the accident pilots pull the autopilot circuit breaker before completing maneuvers.

The airplane impacted soft, muddy terrain. The initial impact crater was about 15 ft deep and contained a majority of the airplane, including the engine, propeller, fuselage, and empennage. A debris field that contained the wings and smaller airplane 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 of the propeller blades remained attached to the propeller hub and exhibited S-bending and curling. The crankshaft was unable to rotate due to the impact damage. Although the examination was limited due to the extensive impact damage, examination of the engine and airframe examination did not reveal any preimpact anomalies.

An autopsy of the pilot was performed by the Calcasieu Parish Coroner's Office, Lake Charles, Louisiana. The cause of death was multiple injuries sustained in an airplane crash. The brain was not available for examination due to the severity of injuries. An internal examination was completed, and no significant natural disease was identified. Toxicology testing performed on the private pilot’s heart tissue by the FAA’s Forensic Sciences Laboratory identified no evidence of impairing drugs.

An autopsy of the flight instructor was performed by the Calcasieu Parish Coroner's Office, Lake Charles, Louisiana. The cause of death was multiple injuries sustained in an airplane crash. The autopsy was limited to an external examination only. A cursory internal examination of the organs was performed and did not identify any natural disease. Toxicology testing for the flight instructor was not possible because there were no suitable specimens.