What happened
A private pilot was conducting a personal cross-country flight in a float equipped airplane under VFR conditions. The flight plan included transiting a narrow mountain pass. Before entering the pass, the pilot observed three aircraft traveling in the opposite direction exiting the area, which led him to believe the passage was clear.
Once inside the pass, clouds closed in rapidly, and the pilot lost visual contact with the river he was using as a navigational reference. The pilot described the conditions as "scuddy" and began a slow descent. During this time, the pilot asked his passenger, a pilot-rated individual in the right seat, if the river was visible. Upon seeing a stream to the right, the passenger panicked, commanded a right turn, and grabbed the flight controls.
After regaining control, the pilot executed a steep left turn. During this maneuver, the aircraft impacted a 45-degree slope. The impact resulted in substantial damage to the wings and fuselage. The occupants were not injured.
Findings
The investigation found that the pilot's decision to enter the pass at the chosen altitude contributed to the loss of visual references. The pilot noted that the accident would have been avoided had the passenger not intervened by grabbing the controls and initiating a right turn.