CESSNA 182H — Bountiful, UT

What happened

The pilot, who owned the dual-flight-control airplane, planned to take the other two occupants (one of whom was also a pilot) on a local tour flight to celebrate their 1-year wedding anniversary. The planned route could not be determined; however, friends and family members stated that they intended to fly past the temple where they were married.

Automatic dependent surveillance broadcast (ADS-B) equipment data indicated a nominal climb profile after takeoff, as the airplane flew past the temple and toward the entrance of a canyon. The airplane then entered the canyon while initially level with the top of its walls. However, as the flight progressed, the top of the canyon walls began to increase at a rate that exceeded the airplane’s climb performance.

Escape from the canyon during the initial stages would have required a precise and coordinated 180° turn that would have resulted in the airplane flying very close to terrain. Instead, the airplane continued until it reached a 1-mile-wide bowl at the end of the canyon that was surrounded by steep rising terrain. Data indicated that the airplane appeared to begin a left turn, possibly in preparation for a 180° turn to escape the canyon but by this time it was approaching the stall speed. The wreckage was located just beyond the final ADS-B target and damage to the airplane and surrounding vegetation was consistent with a near vertical impact, likely after the occurrence of an aerodynamic stall and resultant spin.

Propeller damage signatures along with the airplane’s climb performance indicated the engine was operating throughout. The airplane’s final flap position and observed speed as it passed the halfway point through the canyon were consistent with that required for best angle-of-climb performance. Therefore, the pilots were likely aware of the predicament not long after they entered the canyon.

Weather data indicated that the airplane would not have encountered mechanical turbulence often associated with mountain flight and that no downdrafts or updrafts were in the area.

A forest fire had resulted in smoke and reduced visibility in the entire area with visibility of 5 miles in smoke and haze. However, due to the prevailing wind direction, which pushed smoke toward the rising terrain, it is possible that visibility may have been even lower at the end of the canyon. Video footage of the mountains, along with the statement of a witness who was close to the accident site appeared to confirm this. An airman's meteorological information report indicating mountain obscuration due to smoke and haze was current at the time of the accident.

It could not be determined which pilot was flying the airplane at the time of the accident or why they chose to fly up the canyon. Both pilots were locally based and aware of the terrain. However, it is possible that the limited visibility caused them to misjudge the terrain and entry altitude. An established mountain pass, located 5 miles north of the accident location, followed a route that was about parallel to the accident flight. Although the entrance was indicated by a well-defined reporting point, it is possible that, with the low visibility and potential distractions related to the tour, the pilots may have missed this cue.

Although the owner had more experience flying the airplane, the other pilot had more flight experience and had previously provided the owner with flight instruction. It is possible that a diffusion of responsibility occurred; however, it was not possible to determine the command and decision-making power hierarchy during the accident flight.

An editorial "what led to it / how to avoid it" analysis for this accident is generated separately and will appear here.