What happened
During a takeoff roll, the first officer was designated to operate the aircraft. After completing the pre-takeoff checklist, the captain applied the brakes while the first officer applied full takeoff power. Upon releasing the brakes, the aircraft accelerated to approximately 45 knots before suddenly pulling to the right.
The captain then took control of the airplane and both pilots moved the power levers to the flight idle position. The captain subsequently applied heavy braking and full reverse thrust in an attempt to maintain a straight course; however, the aircraft continued to pull to the right. The aircraft exited the right side of the 4,400-foot long by 75-foot wide runway, descended down an embankment, and came to rest in an area containing large boulders. The aircraft sustained substantial damage to the fuselage and the right wing. The crew was not injured.
The investigation
Mechanical examination of the engine showed that it functioned within acceptable parameters when tested in a test cell. Analysis of the Cockpit Voice Recorder indicated that the crew had planned to use differential power as a method to keep the aircraft on the runway.
Findings
- The captain believed that the left engine continued to produce forward thrust even after the engine control levers were moved into the full reverse position.