ERA24FA283 · Piper PA46 310P

The pilot filed an instrument flight rules (IFR) flight plan from the departure airport with an estimated time en route of 2 hours 47 minutes and a cruising altitude of 12,000 ft mean sea level (msl). The flight planning application the pilot used to file the flight plan provided weather briefing information, which included a convective SIGMET active for the time and route of flight and pilot weather reports (PIREPs) for turbulence and moderate chop; however, it could not be determined whether the pilot reviewed this information. The flight departed about 45 minutes after the pilot’s filed departure time. Flight track data and air traffic control communications showed that, about 1 minute after departing, the pilot contacted air traffic control (ATC) to obtain an IFR clearance. The controller cleared the pilot to his destination as filed, issued a climb to 10,000 ft msl, and provided a weather advisory for moderate and heavy precipitation along the route, which the pilot acknowledged. About 4 minutes later, the controller issued the pilot a climb to 12,000 ft msl, which the pilot acknowledged. About that time, the controller began a position relief briefing with a relieving controller, which took about 2 minutes. About 2 minutes later, the new controller queried the pilot after observing that the flight had deviated left of course. The flight track data showed that, just before the query from the controller, the airplane deviated from its southwesterly ground track and began a 45-second, right 270° turn starting at an altitude of 9,800 ft msl. While in the turn, the airplane descended to an altitude of 8,700 ft msl before climbing back to an altitude of 9,800 ft msl when the airplane rolled out on an easterly ground track. About 1 minute after the query from the controller, the pilot responded, stating he had “lost” something, followed by a similar transmission 27 seconds later. This was the last transmission heard that could be attributed to the accident airplane. The airplane continued on a wavering east track for about 40 seconds, descending back down to 8,700 ft msl before climbing to 9,025 ft msl, after which the airplane entered a tight, right, descending spiral until track data was lost. Postaccident examination of the engine and airframe found no evidence of any malfunction or failure that would have precluded normal operation of the airplane. All fracture surface and control cable separation features were consistent with overload failure. The distribution of the wreckage was consistent with an in-flight breakup of the airplane. The pilot’s recency and currency flying in actual instrument meteorological conditions (IMC) could not be determined. A pilot who had previously flown with the accident pilot reported that, during their last flight together (about 8 months before the accident), the accident pilot engaged the autopilot no later than 5,000 ft above ground level (agl) and continued to use the autopilot for nearly the entire flight. He also reported that, while en route, the pilot used a tablet computer to continue monitoring the weather, including looking at the weather radar. However, based on the accident flight’s heading and altitude deviations were not consistent with the autopilot being engaged; thus, it is likely the pilot was hand-flying the airplane.

A convective SIGMET was active for the area and time of the accident. Weather radar near the time of the accident showed areas of light to heavy or extreme values of reflectivity consistent with convective activity. The cloud bases for the area were between 4,400 ft and 8,900 ft mean sea level (msl) with cloud tops between 12,500 ft and 14,500 ft msl. Based on the available weather information, the accident airplane likely entered IMC about 3 and a half minutes before the accident. Further, the accident airplane likely would have encountered moderate to severe turbulence, based on previous pilot reports and the proximity to the convective activity.

The reduced visibility, turbulence, flight without use of the autopilot, and distraction to regain the proper course would have been conducive to the development of spatial disorientation. The resulting ground track, rapid turning descent, and in-flight breakup were consistent with a loss of control as a result of spatial disorientation.

A review of the ATC services revealed that, although the controller who informed the pilot about moderate and heavy precipitation did not use standard phraseology and did not include an area of extreme precipitation, this did not contribute to the accident. Similarly, the relieving controller’s use of nonstandard phraseology when providing the hazardous inflight weather advisory was not contributory.

Verbatim NTSB analysis and probable cause from the NTSB dataset