Accident Overview
On July 1, 2021, about 1149 mountain daylight time, a Cessna 172R airplane, registration N2388L, was substantially damaged when it impacted terrain near Missoula International Airport (MSO), Missoula, Montana. The pilot and passenger were fatally injured. The flight was conducted as a personal flight under Title 14 Code of Federal Regulations Part 91.
Flight History
The pilot did not file a flight plan with the Federal Aviation Administration and did not inform family members of the destination. Recorded air traffic control audio captured the pilot receiving a clearance for departure on runway 26, which was read back. No further communication with the controller was recorded.
Automatic dependent surveillance-broadcast (ADS-B) data captured the first 5 minutes 48 seconds of the flight. The airplane departed MSO about 1141 on a southwesterly heading at a groundspeed of about 70 to 75 knots. About 3 minutes later, it turned right to a westerly heading toward the Grave Creek Mountain Range, climbing to 3,850 ft mean sea level (msl) with a groundspeed of 70 to 75 knots. At 1143:56, groundspeed decreased to about 68 knots and remained there until the end of recorded data 3 minutes 23 seconds later. The last ADS-B target at 1147:19 showed the airplane at 5,225 ft msl (678 ft above ground level), on a magnetic heading of 271°, about 3.3 miles east of the accident site. Terrain elevation near that point was about 4,547 ft msl.
According to a ground support attendant at the departure airport's fixed-base operator, the pilot requested the fuel tanks be filled “all the way to the top.” The attendant added 28.5 gallons of fuel. The pilot stated he would be flying somewhere remote but did not specify where.
Aircraft Information
The airplane’s weight for the flight was about 2,518 pounds. The Cessna 172R Pilot’s Operating Handbook specifies a maximum takeoff gross weight of 2,450 pounds. Rate of climb at maximum takeoff gross weight, at a pressure altitude of 6,000 ft and 74 knots, was 415 ft per minute at 20°C and 360 ft per minute at 40°C. The stall speed for the flaps-up, power-off configuration was 51 knots calibrated airspeed.
Meteorological Information
The density altitude for MSO around the accident time was calculated to be 5,917 ft. No SIGMET advisories for turbulence were active at the accident location and time. No graphical AIRMET advisories (issued 3 hours apart) were active for the location at either 0900 or 1200 on the day of the accident. Geostationary Operational Environmental Satellite-17 imagery showed mostly clear conditions over the region.
Wreckage and Impact Information
The airplane came to rest on a steep south-facing slope within a tree-covered canyon in the Grave Creek Mountain range, on a magnetic heading of 040°, about 130° to the right of the last ADS-B data point. The valley was surrounded on three sides by higher terrain.
The first identified point of impact was a severed tree trunk about 30 ft above ground level. Tree damage ahead of the wreckage was oriented from the south at a 30° to 45° angle. The terrain slope was about 45°.
All major components of the airplane were found in a small debris area immediately around the airplane, consistent with a low-energy, near-vertical impact. From the impact angle of the tree to the left wing, the airplane was about 30° nose down with little bank angle at impact. Flight control continuity was established for all control surfaces. Postaccident examination of the airframe and engine revealed no mechanical malfunction or failures that would have precluded normal operation.