History of Flight
On December 20, 2018, at about 0904 eastern standard time, a Piper PA-46-350P, registration N307JM, was destroyed in an accident near Mayport, Florida. The private pilot and a pilot-rated passenger were fatally injured. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as a personal flight.
According to FAA air traffic control and radar data, after takeoff, the pilot contacted Orlando Approach and remained in communication for about 17 minutes before being handed off to Jacksonville Air Route Traffic Control Center. The pilot was cleared to climb incrementally to 19,000 ft, leveled for about 5 minutes, then cleared to 23,000 ft msl. At about 0859, the controller advised of moderate and heavy precipitation extending along the route for about 200 miles. One of the pilots acknowledged they would monitor the weather. Radar showed the aircraft in an area of light to moderate echoes (20-30 dBZ). The onboard GPS data indicated slight flightpath deviations around this time, but the aircraft continued north.
At about 0902, the controller broadcast that AIRMETs Tango and Zulu (for turbulence and icing) were available. Shortly after, while flying in an area of base reflectivity returns of 10-30 dBZ and composite reflectivity of 35-50 dBZ, the aircraft began a right turn. Between 0902:03 and 0902:28, it continued the right turn, descending from 23,000 ft to 22,100 ft; then between 0902:28 and 0903:12, it descended further to 14,700 ft msl.
At 0903:08, the controller attempted contact without reply. At 0903:27, while at about 12,200 ft msl, an occupant stated, "we're not ok we need help." The controller asked if he was declaring an emergency, and the occupant replied, "I'm not sure whats happening," followed by "I have anti-ice…everything." At 0903:40, the aircraft was at 10,400 ft msl; the controller asked if they could maintain altitude, and an occupant said they could not. The controller provided vectors to a nearby airport, but no reply was received. At 0904:31, while at about 3,300 ft msl, an occupant advised the controller that the aircraft was inverted and asked for assistance. Radar contact was lost shortly after. Multiple U.S. Coast Guard aircraft and vessels searched, but wreckage was not located until February 5, 2019, about 525 ft north-northwest of the last radar target with altitude.
Pilot Information
FAA records showed that on January 2, 2018, the pilot received a notice of disapproval for the flight portion of his instrument rating practical test; he failed to maintain altitude within 100 ft during level flight and airspeed within 10 knots during a precision approach. On June 20, 2018, he completed the practical test, reporting 289 total flight hours, 70 of which were instrument. He obtained ground and flight training in the accident airplane between December 10 and December 14, 2018, to meet an insurance requirement of 25 hours of dual instruction from a flight instructor who was also a DPE. Training included operating in icing conditions and use of the ice protection system. The instructor noted the pilot needed to review missed approach procedures and instrument phraseology but was "good" with autopilot use. According to the pilot's attorney, at the time of the accident, the pilot had 390 total hours, 290 as pilot-in-command, and 30 hours in the accident make and model.
Aircraft Information
The aircraft was equipped with an enhanced digital display indicator, annunciator panel, a portable Garmin 496 GPS receiver, vertical profile weather radar, and stormscope. The ice protection system comprised pneumatic wing and empennage boots, electrothermal propeller deice pads, heated windshield, heated lift detector, heated pitot head, two alternators, two vacuum pumps, and an alternate static source. The surface deice system was manually engaged via a switch on the environmental/deice panel. The solid-state timer manufacturer stated it could not determine cycle position, and no non-volatile memory was present. The environmental/deice switch panel was too damaged to determine switch position at impact.
Meteorological Conditions
The pilot received a preflight weather briefing at 0717, which included a convective SIGMET outlook valid for the accident area, implying the possibility of severe turbulence, severe icing, and low-level wind shear. He did not request current or forecast icing potential products. The briefing included icing AIRMET Zulu update 1, which specified moderate ice between the freezing level (11,000-14,000 ft msl) and 27,000 ft, valid for the route. The aircraft operated within clouds/precipitation above 14,000 ft from about 0842 until the loss of control. Center Weather Advisory 201, issued at 0822 and valid until 0922, warned of a developing area of thunderstorms moving from 200° at 40 knots, with tops to 30,000 ft and heavy rainfall. The Forecast Icing Potential issued at 0900 indicated 10-40% probability of light to moderate icing at 19,000-23,000 ft above the aircraft's last radar return. At the aircraft's altitude before descent, the temperature was about -16°C. Satellite imagery showed extensive cumuliform cloud cover with tops around 33,000 ft.
Wreckage and Impact Information
The wreckage was recovered on February 5, 2019. Examination revealed extensive damage: the fuselage crown was displaced down, aft fuselage separated, and many components separated including wings, tail surfaces, engine, and propeller. The nose landing gear was extended. Both wings had spar fractures and deformation. No preimpact failure or malfunction was found in the aileron, flap, elevator, or rudder flight control systems. Speedbrakes were fully deployed on the left wing and partially on the right. The landing gear was extended. The lift transducer blade was restricted by sand. Both primary static ports were clear; the alternate static port and pressurization outflow valve static port were blocked by sand. The deice pressure control valves and switches appeared in an unpowered state; many wires were cut during recovery. Due to saltwater submersion, components were not tested. Wing deice boots inflated normally when tested with compressed air except in impact-damaged areas. Electrical wires for deice, pitot heat, and stall warning heat showed no preimpact discrepancies. The annunciator panel was damaged; some bulbs were intact with stretched filaments (fuel imbalance, starter engage, stall warning fail, flaps, windshield heat fail). The NTSB Materials Laboratory found fatigue cracks emanating from the aft face of the right wing spar web, intersecting two holes. All other fracture surfaces were consistent with overstress. The engine exhibited no preimpact failure; compression and suction were observed from all cylinders. The vacuum pumps were examined; the upper pump had a fractured rotor but intact vanes; the lower pump was intact. All three propeller blades remained secured; one was fractured at mid-span, another had a trailing edge fracture, and the third was undamaged.
Additional Information
The Pilot's Operating Handbook warned that severe icing may occur in conditions outside certification, such as freezing rain or mixed icing, and visual cues should prompt immediate exit. Supplement 3 stated that in icing conditions, climb airspeed should be increased to 130 knots, and if below 130 knots, increase power; if maximum continuous power is needed to maintain 130 knots, exit icing conditions immediately. It also noted that aerodynamic buffet would commence 5-19 knots before stall when ice accumulates, and stall warning devices should not be relied upon.
Accident flight performance calculations by Piper Aircraft indicated that during the first climb to 19,000 ft, the aircraft was below the published minimum icing airspeed for about 5 minutes, with a minimum between 108 and 122 KCAS. During the second climb from 19,000 to 23,000 ft, airspeed decreased, and the aircraft was below the minimum icing speed, reaching a minimum between 75 and 88 KCAS. During the descent, airspeed increased above 150 KIAS, exceeding the maximum maneuvering speed.
Advisory Circular 91-74B notes that cloud tops often contain high liquid water content and large drops, and cumulus clouds can have high liquid water content. AC 00-45H states that Convective SIGMETs imply severe turbulence, severe icing, and low-level wind shear, and that supercooled large drops outside icing certification envelopes can be hazardous.
Medical and Pathological Information
Forensic toxicology on pilot specimens detected unquantified N-Butanol and Propanol in liver and muscle, with 62 mg/dL and 59 mg/dL respectively. The report noted that ethanol can be produced postmortem by microbial activity.