History of Flight
On January 11, 2020, at 1801 mountain standard time, a Cessna TR182 airplane, registration N736YU, was destroyed when it struck a radio tower and crashed near Billings, Montana. The pilot and three passengers sustained fatal injuries. The flight was conducted under 14 CFR Part 91 as an instructional flight.
The pilot's wife stated that her husband planned to depart around 1630 and expected to return home about 1730. According to Automatic Dependent Surveillance-Broadcast (ADS-B) data, the airplane departed Billings Logan International Airport (BIL), landed at Big Horn County Airport (00U) in Hardin, Montana at about 1715, and departed 00U at about 1740. Flight data from the multi-function display (MFD) showed that the airplane began an immediate climb after departure and established a cruise altitude of about 4,796 ft msl at 1747:43, maintaining a height above terrain between 1,400 and 2,100 ft agl for the remainder of the flight.
The ADS-B data indicated the airplane flew a straight track northwest (about 269° magnetic) until about 1753:53, then made a slight left turn to 257° and continued on that heading. MFD data showed rising terrain about 40 seconds before the crash. The final MFD data point, recorded at 1801:22 at an altitude of 4,954 ft msl (35 ft agl), was located about half a nautical mile from the initial impact point. The pilot's wife contacted local law enforcement around 2000 when he did not return.
Individuals who flew with the pilot reported that he typically flew at about 1,000 ft agl over terrain and frequently used the autopilot's altitude hold function. He did not carry a sectional chart, relying instead on the MFD's map for terrain and chart information. According to the pilot's business partner, a photograph taken by a passenger during the accident flight showed the pilot seated in the right seat. Passengers were sometimes allowed to fly from the left seat, typically at altitudes between 4,000 and 5,000 ft msl. A passenger who flew with the pilot a week prior recalled a similar flight to 00U that included circling a landmark, with altitudes maintained at about 1,000 ft agl and autopilot used.
MFD flight data from a previous flight several days earlier showed the pilot flew a similar course from 00U to Roundup Airport (RPX). During that flight, the airplane passed within 0.3 nautical miles of the same 185-ft radio tower at an altitude of 4,680 ft msl (580 ft agl) and landed at RPX about 15 minutes later.
Personnel Information
The co-owner of the accident airplane reported that the pilot began flying in 1972 and was familiar with the Billings area. The pilot's wife described him as well-rested on the day of the accident and noted no abnormal behavior that day or in preceding days.
Aircraft Information
The Cessna TR182 was equipped with an Aspen Evolution primary flight display (PFD) mounted in front of the left seat and a Garmin GTN750 MFD on the center panel. The Aspen PFD displayed barometric altitude from its internal air data computer; the altimeter setting was displayed below the altitude tape. According to the installation manual, the altitude tape should be within 40 ft of the calibrated test altitude, but the altimeter setting at the time of the accident could not be determined as the unit did not record data. An adjacent Aspen MFD also did not record data.
The GTN750 featured an obstacle range option and topography overlay. According to the manufacturer, the GPS altitude (GSL) was displayed in the top left corner of the map page. The obstacle range could display unlighted obstacles below 1,000 ft agl, but not obstructions below 200 ft agl. The GTN750 recorded pressure and barometric altitude from the Aspen air data computer; the final data point showed a barometric altitude of 4,954 ft msl and a GPS altitude of 4,747 ft GSL.
Wreckage and Impact Information
The wreckage was located in mountainous terrain at an elevation of about 4,252 ft msl. The initial impact point was a 185-ft-tall radio tower, struck at about 65 ft above ground (4,809 ft msl). Several sections of the outboard left wing were found near the tower, with two pieces exhibiting longitudinal signatures consistent with wire impact. The remaining left wing section was found about 350 ft from the main wreckage. Airframe and engine fragments were distributed along a debris path oriented at about 295°. The main wreckage, including the right wing, fuselage, empennage, and engine, came to rest about 1,450 ft northwest of the initial impact point in a coulee. A 5-ft intermediate ground scar was located about 250 ft beyond the main wreckage.
Control cables for the rudder, aileron, and elevator were recovered and showed multiple overload failures. The flap motor actuator measured 0.1 inch, consistent with retracted flaps. The engine crankshaft could only be partially rotated due to impact damage; the ignition system showed normal operation and wear, with no evidence of oil starvation or foreign object ingestion.
Additional Information
According to FAA Advisory Circular 70/7460-1L, structures exceeding 200 ft above ground level (AGL) should be marked and/or lighted, but the FAA may also recommend marking for shorter structures due to location. The FAA sectional chart valid from September 12, 2019, to March 26, 2020, did not list the tower as an obstacle, as the chart only marks obstructions above 200 ft AGL. The maximum elevation figure for the sector was 5,100 ft msl.
Under 14 CFR 77.17, an object is considered an obstruction if it exceeds 200 ft AGL or certain airport-related heights. Title 14 CFR 91.119 specifies minimum safe altitudes: over other than congested areas, an aircraft must maintain at least 500 ft above the surface and remain at least 500 ft from any person, vessel, vehicle, or structure.