Socata TBM-700

After landing at Brasília-Nelson Piquet Airport, the single engine airplane went out of control and veered off runway. It went down into a ravine and came to rest into trees. All five occupants evacuated safely while the aircraft was destroyed. The pilot reported he encountered strong winds upon landing.

The pilot was performing a short cross-country flight, which was his third solo flight in the high-performance single-engine airplane. The airplane departed and climbed to 20,000 ft mean sea level (msl) before beginning to descend. About 8 minutes before the accident, the airplane was southbound, descending to 11,000 ft, and the pilot established communications with air traffic control (ATC). About 4 minutes later, the controller cleared the pilot to descend to 10,000 ft msl and proceed direct to his destination; the pilot acknowledged the clearance. While descending through 13,000 ft msl, the airplane entered a descending left turn. The controller observed the left turn and asked the pilot if everything was alright; there was no response from the pilot. The controller’s further attempts to establish communications were unsuccessful. Following the descending left turn, the airplane entered a high speed, nose-down descent toward terrain. A witness observed the airplane at a high altitude in a steep nose-down descent toward the terrain. The witness noted no signs of distress, such as smoke, fire, or parts coming off the airplane, and he heard the airplane’s engine operating at full throttle. The airplane impacted two powerlines, trees, and the terrain in a shallow descent with a slightly left-wing low attitude. Examination of the accident site revealed a long debris field that was consistent with an impact at a high speed and relatively shallow flightpath angle. All major components of the airplane were located in the debris field at the accident site. Examination of the airframe and engine revealed no preimpact mechanical malfunctions or failures with the airplane that would have precluded normal operation. A performance study indicated the airplane entered a left roll and dive during which the airplane exceeded the airspeed, load factor, and bank angle limitations published in the Pilot’s Operating Handbook (POH). An important but unknown factor during these maneuvers was the behavior of the pilot and his activity on the flight controls during the initial roll and dive. The pilot responded normally to ATC communications only 98 seconds before the left roll started. It is difficult to reconcile an alert and attentive pilot with the roll and descent that occurred, but there is insufficient information available to determine whether the pilot was incapacitated or distracted during any part of the roll and dive maneuver. Although all the available toxicological specimens contained ethanol (the alcohol contained in alcoholic drinks such as beer and wine), the levels were very low and below the allowable level for flight (0.04 gm/dl). While it is possible that some of the identified ethanol had been ingested, it is also possible that all or most of the identified ethanol was from sources other than ingestion (such as postmortem production). In either case, the levels were too low to have caused incapacitation. It is therefore unlikely that any effects from ethanol contributed to the circumstances of the accident. There was minimal available autopsy evidence to support any determination of incapacitation. As a result, it could not be determined from the available evidence whether medical incapacitation contributed to the accident.

The pilot was conducting an instrument approach at the conclusion of a cross-country flight when the airplane entered a shallow climb and left turn away from the runway heading about 0.5-mile from the intended runway. According to airspeeds calculated from automatic dependent surveillance-broadcast position data, the airplane’s calibrated airspeed was 166 knots when it crossed over the final approach fix inbound toward the runway and was about 84 knots when it was on a 0.5-mile final approach. The airplane continued to decelerate to 74 knots while it was in a shallow climb and left turn away from the runway heading. At no point during the approach did the pilot maintain the airframe manufacturer’s specified approach speed of 85 knots. The airplane impacted the ground in an open grass field located to the left of the extended runway centerline. The airplane was substantially damaged when it impacted terrain in a wings level attitude. The postaccident examination did not reveal any anomalies that would have precluded normal operation of the airplane. The altitude and airspeed trends during the final moments of the flight were consistent with the airplane entering an aerodynamic stall at a low altitude. Based on the configuration of the airplane at the accident site, the pilot likely was retracting the landing gear and flaps for a go around when the airplane entered the aerodynamic stall. The airplane was operating above the maximum landing weight, and past the aft center-of-gravity limit at the time of the accident which can render the airplane unstable and difficult to recover from an aerodynamic stall. Additionally, without a timely corrective rudder input, the airplane tends to roll left after a rapid application of thrust at airspeeds less than 70 knots, including during aerodynamic stalls. Although an increase in thrust is required for a go around, the investigation was unable to determine how rapidly the pilot increased thrust, or if a torque-roll occurred during the aerodynamic stall.

The commercial pilot was conducting an instrument approach following a 3.5-hour cross-country instrument flight rules (IFR) flight in a single-engine turboprop airplane. About 1.6 miles from the runway threshold, the airplane began a climb consistent with the published missed approach procedure; however, rather than completing the slight left climbing turn toward the designated holding point, the airplane continued in an approximate 270° left turn, during which the airplane's altitude varied, before entering a descending right turn and impacting terrain. Tree and ground impact signatures were consistent with a 60° nose-low attitude at the time of impact. No distress calls were received or recorded from the accident flight. A postimpact fire consumed a majority of the cockpit and fuselage. Weather information for the time of the accident revealed that the pilot was operating in IFR to low IFR conditions with gusting surface winds, light to heavy snow, mist, cloud ceilings between 700 and 1,400 ft above ground level with clouds extending through 18,500 ft, and the potential for low-level wind shear and clear air turbulence. The area of the accident site was under AIRMETs for IFR conditions, mountain obscuration, moderate icing below 20,000 ft, and moderate turbulence below 18,000 ft. In addition, a winter storm warning was issued about 6 hours before the flight departed. Although the pilot received a weather briefing about 17 hours before the accident, there was no indication that he obtained updated weather information before departure or during the accident flight. Examination of the airframe and engine did not reveal any preimpact anomalies that would have precluded normal operation; however, the extent of the fire damage precluded examination of the avionics system. The airplane was equipped with standby flight instruments. An acquaintance of the pilot reported that the pilot had experienced an avionics malfunction several months before the accident during which the airplane's flight display went blank while flying an instrument approach. During that occurrence, the pilot used ForeFlight on his iPad to maneuver back to the northeast and fly the approach again using his own navigation. During the accident flight, the airplane appeared to go missed approach, but rather than fly the published missed approach procedure, the airplane also turned left towards to northeast. However, it could not be determined if the pilot's actions were an attempt to fly the approach using his own navigation or if he was experiencing spatial disorientation. The restricted visibility and turbulence present at the time of the accident provided conditions conducive to the development of spatial disorientation. Additionally, the airplane's turning flight track and steep descent profile are consistent with the known effects of spatial disorientation.