Incident Overview
An instructor and student pilot encountered extreme turbulence while climbing to 2000 feet. In response, the instructor took the controls and retarded power to reduce speed and lose altitude. The aircraft descended from 1800 feet to 1300 feet before the throttle was advanced. When the throttle was advanced, the engine did not respond.
Emergency Landing Attempt
With the engine failing to restart, the pilots attempted a landing on a highway. During the landing, while maneuvering to avoid traffic, the right wing struck a sign. This impact caused a loss of directional control. The aircraft then went through a series of yawing and sliding maneuvers until it came to a stop on the shoulder of Highway 18.
Post-Accident Examination
An examination of the engine disclosed no preimpact malfunction or failure. The engine was subsequently started and idled satisfactorily, indicating no mechanical issue before the accident.
Investigation Findings
The source does not state a probable cause for the engine failure or the accident. The examination found no preimpact malfunction, suggesting the engine failure may have been transient or due to other factors not specified in the report.