History of Flight
On June 5, 2020, about 1520 eastern daylight time, a Piper PA-31T, registration N135VE, was destroyed when it crashed near Eatonton, Georgia. The two pilots and three passengers on board sustained fatal injuries. The flight was operated as a personal flight under Title 14 Code of Federal Regulations Part 91.
The pilot, who owned the airplane, occupied the left front seat, and a pilot-rated passenger sat in the right front seat. The pilot filed an instrument flight rules (IFR) flight plan from Williston Municipal Airport (X60), Florida, to New Castle Henry County Marlatt Field (UWL), Indiana. The airplane departed at 1413, and shortly after, one of the pilots established contact with air traffic control (ATC).
Review of ATC communications, radar data, and ADS-B data showed the airplane flew north at 26,000 ft msl. About 50 miles south of Eatonton, one pilot requested a deviation to the right to avoid weather. At 1518:02, while passing over Eatonton, a pilot advised ATC of a direct course to the destination on a 353° heading. At that time, the airplane was at about 26,450 ft msl with a groundspeed of 262 knots. Radar data indicated a left turn toward the new heading, then a right turn about 20 seconds later. At 1519:17, ATC attempted contact; the airplane was at 22,000 ft msl, heading 292°, ground speed 178 knots. Two seconds later, an unintelligible transmission was recorded, followed by "made it worse." No further communications were received. Radar showed the airplane turning right and entering a rapid descent, with last contact at about 1520 when altitude read "0", ground track 097°, and groundspeed 97 knots.
Witnesses observed the airplane descending below clouds, recording video of a flat spin with fire on both sides of the fuselage near the wings, black smoke, and parts separating. The wreckage was found in densely wooded terrain.
Personnel Information
The pilot held a private pilot certificate with single and multiengine ratings and an instrument rating. His logbook was not found; his last FAA medical certificate was issued in March 2020, reporting 2,000 flight hours. His actual instrument experience was unknown. He completed an approved Piper PA-31 simulator training course in April 2020.
The pilot-rated passenger held a student pilot certificate. Remnants of his logbook were found but too burned to read. His last medical certificate was from July 2018, reporting 15 flight hours.
Aircraft Information
The Piper PA-31T was powered by two Pratt & Whitney Canada PT6A-135 turboprop engines, each driving a five-bladed propeller. The airplane was certified for single-pilot operation and flight into known icing. It was equipped with pneumatic deice boots on wing and tail leading surfaces, an autopilot, but no autothrottle.
Meteorological Information
The pilot obtained a preflight weather briefing via ForeFlight at about 1300, including convective SIGMETs 65E and 69E valid from 1255 to 1455, which implied severe turbulence, severe icing, and low-level wind shear. After expiration, convective SIGMET 78E was issued for thunderstorms with tops above 45,000 ft msl, covering the route and accident site.
The briefing also included AIRMETs Sierra and Tango for IFR conditions and turbulence, synoptic conditions, METARs, TAFs, and static charts. The pilot did not obtain current or forecast icing products. Those products showed high probability of icing and supercooled liquid droplets near the accident time.
Radar reflectivity data indicated echoes of 10-25 dB along the flight track between 1517 and 1520, consistent with moderate-to-severe icing conditions. Satellite imagery showed cloud tops at 32,000 ft msl over the accident site.
Wreckage and Impact Information
The main wreckage was found inverted, with fire consuming most of the fuselage. The left engine was not located. The outboard sections of both wings and the tail separated in flight. Postaccident examination revealed no preimpact mechanical malfunctions that would have precluded normal operation.
The right engine and its propeller system were recovered; engine examination showed no preimpact anomalies, except that its fuel source had separated in flight.
Medical and Pathological Information
Autopsies of both pilots determined cause of death as multiple blunt force injuries. Toxicology identified amlodipine in the pilot (a blood pressure medication not considered impairing) and glucose in the pilot-rated passenger's urine. No blood was available for carbon monoxide testing.
Tests and Research
An airplane performance study using ADS-B and GPS data from a recovered Appareo Stratus 2S device showed an uneventful 1-hour 7-minute flight until the last 90 seconds. The autopilot appeared engaged during the initial turn, then the airplane dynamics suggested an open-loop situation with the pilot hands-off despite autopilot disengagement.
Data showed a 10° left bank for about 20 seconds, then a roll to the right to about 120° bank over 70 seconds at about 1-2° per second. Simultaneously, the airplane experienced pitch oscillations for 60-65 seconds. The last ADS-B return was at 1519:07, and the last radio transmission at 1519:19, with a descent rate of about 7,000 ft per minute per GPS data.
The airplane's maximum operating speed at 26,000 ft was 182 knots, which was not exceeded until deviation from level flight. The performance study noted that the turbulent weather associated with convective activity could have precipitated or contributed to the airplane dynamics in the final 90 seconds, but the observed dynamics were not consistent with an ice encounter.
All recovered flight controls and structure showed overload failures, and no preimpact anomalies were found.