Incident Overview
A pilot experienced elevator control difficulties and yoke vibrations shortly after encountering turbulence during cruise. The pilot declared an emergency and requested vectors to the nearest airport. Mountain Home Air Force Base Radar Approach Control (RAPCON) directed the pilot to Glenns Ferry Airport.
Approach and Landing
On approach, the pilot observed large 'X' marks on the runway, indicating the airport was closed. Due to the nature of the emergency, the pilot elected to continue the approach. In dusk conditions, the pilot did not see large dirt mounds obstructing the runway until committed to landing. The pilot attempted to steer clear during touchdown and rollout but was unable, colliding with one or more mounds before coming to rest.
Investigation Findings
Investigation revealed that the elevator tab control rod end had torn free from the tab horn. The horn showed evidence of previous wear that necessitated an oversize bearing. Continued wear had reduced the cross-section of the horn, rendering it unable to withstand the turbulence-induced flight loads.
Additional Information
At the time of the mishap, Mountain Home Air Force Base was not on the Class B NOTAM distribution.