Incident Overview
An aircraft flying over a mountain pass encountered turbulence that the pilot described as 'severe'. During the encounter, the aircraft lost between 500 and 1,000 feet of altitude and turned 180 degrees. A 180-degree climbing turn was initiated, leading the aircraft back into the turbulent area.
Second Encounter and Control Issues
Upon the second entry into turbulence, aileron and elevator controls functioned normally, but rudder inputs became ineffective. The pilot determined that the aircraft would not be able to clear a ridge ahead and subsequently flew into the rising terrain in a nose-high attitude.
Post-Recovery Findings
After the aircraft was recovered, it was noted that the rudder had failed above the top hinge point. A flight precaution was issued by Juneau Flight Service Station (FSS) warning of moderate to severe turbulence below 5,000 feet, specifically near mountain passes. The pilot did not obtain a weather briefing prior to the flight.
Key Facts
- The turbulence was characterized by the pilot as 'severe'.
- Altitude loss ranged from 500 to 1,000 feet.
- The aircraft performed a 180-degree turn, then a climbing turn back into turbulence.
- Rudder control was lost after the second turbulence encounter while aileron and elevator remained normal.
- The aircraft impacted terrain in a nose-high attitude.
- Post-accident inspection revealed rudder failure above the top hinge point.
- A flight precaution for turbulence near mountain passes was active.
- No weather briefing was requested by the pilot.