N40KAMooney M20M · 1993

On October 28, 2021, about 0911 Pacific daylight time, a Mooney M20M, N40KA, was substantially damaged when it was involved in an accident near Snoqualmie, Washington. The private pilot sustained fatal injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

The pilot had purchased the airplane just days before the flight and was flying it from the purchase location of Arlington Municipal Airport (AWO), Arlington, Washington, to Magic Valley Regional Airport (TWC), Twin Falls, Idaho. The morning of the flight, the pilot filed an IFR flight plan from AWO to TWC, and he received a ForeFlight weather briefing that identified moderate icing conditions along the planned route of travel. The relative humidity during the planned time along the route of flight was 98%. The weather briefing indicated that during the planned flight time, the base freezing level was 5,000 ft msl and the top freezing level was 22,000 ft msl.

A review of air traffic control (ATC) communications and radar data revealed that the airplane departed AWO about 0842. The pilot initiated an eastbound turn, which was abnormal for departures from AWO airport, and the controller questioned the pilot about the abnormal turn and subsequently issued the pilot a heading to the south. The pilot advised ATC that the turn was not intentional and that the autopilot may have been the issue. The pilot corrected course; however, at 0900, the airplane made a hard right turn to the northwest in the opposite direction of the planned route of flight. The airplane’s altitude was about 14,000 ft msl when a handoff was made from the Seattle Terminal Radar Control Approach facility to the Seattle Air Route Traffic Control Center.

The pilot established communication with the ARTCC controller and stated that he had an issue with the autopilot and that he was correcting to the southeast. The airplane’s altitude was about 14,000 ft msl when the pilot made a left turn to the southeast, and the controller acknowledged the heading correction and subsequently cleared the airplane to depart 14,000 ft msl and climb to 17,000 ft msl. The controller made the pilot aware of multiple pilot reports (PIREPs) for moderate rime icing conditions between 12,000 ft msl and 18,000 ft msl. The controller offered the pilot an altitude of 19,000 ft msl to get above the ice, and the pilot accepted. At 0903, the airplane’s altitude was 16,000 ft msl when the controller informed the pilot that he was about 20° left of course and to maintain his present heading. About 0904, after climbing to an altitude of 16,300 ft msl, the airplane began a rapid descent with a series of tight spiral turns. Communication between the controller and the pilot became broken and unreadable.

The controller solicited an airplane in the area to attempt communication with the accident airplane on the emergency frequency 121.5 and to relay the controller’s instructions. After multiple attempts to communicate, the relaying airplane informed the controller that the pilot of the accident airplane reported that the airplane was out of control. The airplane descended through 5,400 ft msl when a simultaneous loss of radar contact and communication occurred shortly after 0910. The airplane was the subject of an alert notice and was located by search and rescue personnel in the Snoqualmie National Forest, Snoqualmie, Washington, about 1 mile southeast of Calligan Lake.

According to a friend of the pilot, the pilot transitioned from the use of a paper logbook to ForeFlight’s pilot logbook. Foreflight indicated that the pilot had amassed 1,561.4 hours of flight experience. Following a 6-year hiatus from flying, the pilot resumed flying 5 months before the accident and had amassed 13.4 hours of flight experience in a Cessna 172. Further, the Foreflight track log identified six flights in the accident airplane that were not documented in the pilot’s logbook. The six flights were conducted over the 3 days before the accident and totaled 5.1 hours of flight time. The pilot’s logbook contained no record of a flight review or an instrument proficiency check since the pilot had resumed flying.

According to the previous owner, the airplane underwent an annual inspection on September 22, 2021. The airframe, engine, and propeller logbooks were provided to the pilot by the previous owner at the time of the sale and were not located during the investigation. The previous owner surmised that the logbooks were on board the airplane at the time of the accident.

A review of the meteorological conditions that existed surrounding the time of the accident revealed instrument meteorological conditions. AIRMET Z was active for light to moderate rime icing and the presence of clear ice conditions. PIREPs confirmed the icing conditions and low-level turbulence in the vicinity of the accident site.

The northwest section of the Surface Analysis Chart at 0800 depicted a low-pressure system over the Washington Pacific coastline associated with a frontal wave, with a warm front extending southeastward over Washington and in the immediate vicinity of the accident site. A secondary trough of low pressure extended southeastward from the front across Washington, northeast Oregon, and into western Idaho. A high-pressure system was located over central Idaho.

The station models in the vicinity of the accident site depicted light winds, obscured skies in rain and fog, with temperatures ranging from 50°F in the Seattle area to near 37° F immediately southeast of the accident site at Ellensburg, Washington. Temperature-dew point spreads were less than 2° F over the area with light rain and fog.

To determine the conditions over the accident site, a high-resolution rapid refresh (HRRR) numerical model was obtained from the National Oceanic and Atmospheric Administration Air Research Laboratory archive for the nearest grid point to the accident site about the time of the accident. The HRRR sounding depicted an accident site elevation near 3,681 ft, with cloud tops estimated at 20,000 ft msl. The freezing level was identified at 6,000 ft msl and indicated a high potential for light-to-moderate clear icing and rime ice from the freezing level through 20,000 ft msl.

According to the previous owner, the airplane underwent an annual inspection on September 22, 2021. The airframe, engine, and propeller logbooks were provided to the pilot by the previous owner at the time of the sale and were not located during the investigation. The previous owner surmised that the logbooks were on board the airplane at the time of the accident.

The airplane wreckage was located in densely wooded, mountainous terrain and distributed within a 21 ft by 15 ft area. Damage to the outboard left and right wings was consistent with the airplane initially impacting two trees about 20 ft above the base of the trees. The northwestern border of the wreckage consisted of the engine and propeller sections, which sustained thermal damage. The Nos. 1 and 2 cylinders were liberated from engine block, and the three propeller blades were liberated from the propeller hub. The cabin and fuselage were consumed by the post-impact fire. The airplane’s tail section including the rudder and elevators, formed the southwestern border of the wreckage.

An examination of the engine and airframe revealed no anomalies or mechanical malfunctions that would have precluded normal operations. The airplane’s anti-ice and de-ice systems had sustained significant thermal damage. The TKS ice protection panels affixed to the leading edges of the vertical and horizontal stabilizers were present and had sustained thermal damage. The windshield spray-bar that provided de-ice protection and the propeller slinger ring that also provided de-ice protection were not visibly identifiable. The propeller blades were equipped with de-icing boots and had sustained thermal damage. The supplement to the pilot’s operating handbook and the airplane flight manual contained a warning that stated, “INTENTIONAL FLIGHT INTO KNOWN ICING IS PROHIBITED.”