N3720RCessna 172H · 1966

On September 12, 2020, about 2152 mountain daylight time, a Cessna 172H airplane, N3720R, was substantially damaged when it was involved in an accident near Seeley Lake, Montana. The pilot and one passenger were fatally injured, and one passenger was seriously injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

According to a representative of the flying club that owned the airplane, the airplane was based at Seeley Lake Airport (23S), and the pilot was a club member. The representative reported that earlier on the day of the accident, the pilot flew the airplane from 23S to Bowman Field Airport (3U3), Anaconda, Montana, where he and the passengers participated in a golf event. The accident occurred as the airplane approached 23S on the return flight from 3U3.

A witness, who was located at 23S, heard the airplane fly towards the airport from the south and continue past the airport to the north until he could no longer hear it. A witness near the accident site reported that the airplane’s engine “sputtered” before the airplane impacted the ground. The surviving occupant had no recollection of the accident or the circumstances surrounding it.

Local law enforcement personnel began a search for the airplane after witnesses reported hearing a crash, and they located the accident site early on September 13, 2020, about 3/4-mile north of 23S.

The pilot held a private pilot certificate with an airplane single-engine land rating and was not instrument rated. The pilot was issued a Federal Aviation Administration (FAA) third-class airman medical certificate on September 11, 2020, with the limitation, must wear corrective lenses. At the time of the medical examination, the pilot reported logging 550 total hours of flight experience.

The flying club rules stated that the airplane should be returned for the next pilot at least half full of fuel as 23S had no fuel services available. According to the flying club’s “Tach Time Log” sheet that was recovered from the airplane, the airplane was last refueled on the day of the accident by the pilot with about 24 gallons of fuel at Deer Lodge City-County Airport (38S), Deer Lodge, Montana. It is unknown whether the refueling stop took place on the inbound flight to 3U3, which was located about 15 nautical miles south of 38S, or on the return flight to 23S.

A National Oceanic and Atmospheric Administration High-Resolution Rapid Refresh model created for the accident site indicated wind near the surface from the west at 4 knots. A radiation inversion was located at 130 ft above ground level (agl), and a subsidence inversion was located at 558 ft agl.

Smoke imagery and surface observation reports indicated that there were many wildfires active in the Pacific Northwest at the time of accident. An experimental High-Resolution Rapid Refresh Smoke model identified areas that exhibited intense fires and forecasted smoke dispersion. The smoke model indicated a concentrated area of smoke flowing from the west. The accident site, from the near surface to 1,000 ft agl, showed increased concentrated levels of smoke.

A search for PIREPs revealed that no reports were made within 75 miles of the accident site from 2 hours before to 2 hours after the accident time. There were no active SIGMETs or Center Weather Service Unit Meteorological Impact Statements or Center Weather Advisories for the accident site at the time of the accident.

AIRMET advisory Sierra was valid for the accident site at the accident time. AIRMET Sierra warned of instrument flight rules (IFR) conditions and mountain obscuration due to haze and smoke. At 1408, the National Weather Service in Missoula, Montana, issued an Area Forecast Discussion (AFD) that discussed reducing visibilities due to wildfire smoke during the accident day and into the following day. The AFD stated, in part:

Air quality and visibility expected to steadily degrade due to increasing wildfire smoke.

Current satellite imagery shows the progression of wildfire smoke has begun to infiltrate northwest Montana and north Idaho this afternoon. Smoke will continue pushing eastward, dropping visibility and degrading air quality as it fully engulfs the rest of the Northern Rockies by Sunday. Weather observations and webcam images across eastern Washington and eastern Oregon show visibility has lowered to less than one mile, and the same should be expected for north central Idaho and western Montana.

The astronomical data obtained for the accident site indicated that sunset on the day of the accident was at 1949, and the end of twilight was at 2019. At the time of the accident, the moon was below the horizon.

The pilot did not request a weather briefing through the FAA-contracted Automated Flight Service Station provider Leidos. Additionally, a check of the third-party vendor ForeFlight was accomplished and revealed that the pilot did not request weather information through them. Additionally, no record of the pilot receiving or retrieving any other weather information before or during the accident flight was located.

The flying club rules stated that the airplane should be returned for the next pilot at least half full of fuel as 23S had no fuel services available. According to the flying club’s “Tach Time Log” sheet that was recovered from the airplane, the airplane was last refueled on the day of the accident by the pilot with about 24 gallons of fuel at Deer Lodge City-County Airport (38S), Deer Lodge, Montana. It is unknown whether the refueling stop took place on the inbound flight to 3U3, which was located about 15 nautical miles south of 38S, or on the return flight to 23S.

Local law enforcement and FAA personnel responded to the accident site. The first law enforcement officer that arrived at the accident site stated that there was haze and that the visibility was between 1 to 3 miles. The smell of fuel assisted first responders in locating the airplane. The accident site was in heavily wooded terrain at an elevation of about 4,325 ft (about 69 ft higher in elevation than the airport).

All major components of the airplane were located at the site. The initial point of impact was the top of about 75-ft-tall trees. The airplane traveled about 365 ft through the tree tops before coming to rest. The direction of travel through the trees was about 152°. There was no post impact fire. The left wing separated and was found about 159 ft from the main wreckage. The airplane’s tachometer indicated 2,267.75 hours. One propeller blade had a slight aft twist about ¾ the length of the blade. The other blade was bent aft and twisted near the tip. Both blades exhibited chordwise scoring and leading edge gouges. The spinner dome was crushed with torsional deformation. The fuel selector was on both tanks. Residual fuel was found in the fuel strainer and electric fuel pump.

Postaccident examination of the airframe and engine revealed no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation. The propeller manufacturer reviewed photographs of the propeller and noted that the damage to the propeller was consistent with it rotating under power at impact.

The Office of the Department of Justice, Forensic Science Division, Missoula, Montana, conducted an autopsy on the pilot. The medical examiner determined that the cause of death was “blunt force injuries.”

Toxicology testing performed by the FAA’s Forensic Sciences Laboratory on the pilot’s specimens detected no drugs of abuse.