What happened
While navigating through a mountain pass, the pilot was following a company airplane positioned approximately 3 to 5 miles ahead. During the flight, the pilot lost sight of the lead aircraft and failed to execute a necessary right turn. Consequently, the pilot flew straight ahead into a canyon and entered clouds.
In an attempt to recover, the pilot initiated a 180-degree turn, reduced airspeed, and began a descent. After observing a snow-covered glacier, the pilot performed a landing on the surface.
Findings
An investigation into company procedures revealed several discrepancies regarding training and operational standards. Although the chief pilot had previously conducted a training flight with the pilot to demonstrate specific passes and procedures, the company's training manual contained no reference to instruction for mountainous terrain or mountain pass operations. Furthermore, while the company requires pilots to view a video outlining policies for mountain flying and pass penetration, this training requirement was not documented in the manual.
Additionally, the company operations manual lacked guidance regarding minimum weather operations, mountain operations, or procedures for operating in mountain passes.