What happened
During a night approach under visual meteorological conditions, the crew of the aircraft experienced a difficult landing sequence. After an initial missed approach, the pilot in command continued the approach despite concerns regarding a long touchdown. The main landing gear made contact with the runway approximately 1,650 feet beyond the approach end of the 4,801-foot runway. The nose gear touched down roughly 2.4 seconds later, leaving approximately 2,680 feet of runway remaining.
Upon touchdown, the pilot attempted to apply the brakes but believed the system was non-functional. The second in command also attempted to depress the brake pedals without apparent success. Although the pilot in command considered initiating a go-around, the second in command indicated it was too late to do so. The power levers were advanced to takeoff power for several seconds before being returned to idle, and the thrust reversers were not engaged until 14 seconds after the aircraft reached the ground. The aircraft subsequently exited the runway, striking a gravel berm and coming to a stop about 816 feet past the runway end. While there were no reported fatalities, the impact caused a passenger seat to dislodge from its track, which contributed to injuries.
Findings
Investigation of the flight data and cockpit recordings indicated that the thrust reverser activation delay was a primary factor in the overrun. The pilot's decision-making led to a 22-second delay in deploying the reversers. Furthermore, the crew failed to follow established procedures, which required activating thrust reversers after nosewheel touchdown and then applying brakes. The crew also failed to utilize the emergency brake despite the perceived brake failure.
Technical analysis showed that the braking effect was likely minimized because the engines were at high power and the airbrakes remained stowed. While the airbrakes were armed, the cause of their failure to deploy remained inconclusive. Additionally, investigators found that a passenger seat had been improperly installed in the wrong orientation, with the shear plungers in the raised position, which allowed the seat to detach from the track during the impact.