Incident Overview
During climb to cruise, the captain advanced the left engine power lever, which jammed in the full forward position. This caused an engine overtorque and overtemperature condition, prompting the captain to shut down the left engine. After shutdown, both primary flight display screens went blank. The captain reset the right generator, restoring power and display functions. Due to the engine shutdown, the captain diverted to a nearby airport for a single-engine precautionary landing under visual flight rules.
Approach and Landing
Wind conditions at the airport were 290 degrees at 18 knots, and runway 27 was in use. During descent, the crew became confused about their true heading. They identified runway 27 only about one minute before touchdown because of a 50-degree difference in heading indications caused by the instrument gyros having been reset. Accurate heading information was available from the airplane's compass but was not used. Having declared an emergency, the crew was cleared to land on any runway and chose runway 18.
Loss of Control
After touchdown, the captain applied reverse thrust on the right engine, causing the airplane to veer right. The airplane flight manual’s single-engine approach and landing checklist states that after landing, braking and reverse thrust are to be used as required to maintain control. The airplane continued right, departed the runway, struck terrain, flipped over, and came to rest inverted. At touchdown, about 5,000 feet of runway remained. The loss of directional control likely began when reverse thrust was applied shortly after touchdown, exacerbated by the strong crosswind.
Postaccident Findings
Examination revealed a clevis pin incorrectly installed by unknown maintenance personnel, which jammed the left engine power lever. No other anomalies were found that would have prevented normal operation.
Probable Cause
The captain's failure to maintain directional control during landing with one engine inoperative. Contributing to the accident was an improperly installed clevis pin in the left engine power lever, the crew’s delay in accurately identifying their heading, and their subsequent selection of a runway with a strong crosswind.