Approach and Landing
The aircraft was on approach to the destination airport in night visual meteorological conditions. After losing sight of the runway once and executing a go-around, the flight crew continued the approach. The pilot in command (PIC) stated that he believed they would land long. The main landing gear touched down near the 1,000-foot marker of the 4,801-foot runway at approximately the landing reference speed (Vref) of 120 knots. The PIC applied brakes but perceived they were not working; thrust reversers had not yet been activated. He alerted the second in command (SIC), who also depressed the brake pedals with no apparent effect. The PIC suggested a go-around, but the SIC responded it was too late.
Accident Sequence
The aircraft traveled off the end of the runway, struck a gravel berm, and came to rest about 816 feet beyond the runway end. During impact, a passenger seat dislodged from its seat track and was found on the cabin floor with the passenger still restrained. Cockpit voice recorder, video, and performance data indicated the main gear touched down at Vref approximately 1,650 feet beyond the approach end of the runway. The nose gear touched down 2.4 seconds later at about 2,120 feet, leaving approximately 2,680 feet of runway remaining. Engine data showed that about 8 seconds after weight-on-wheels, the power levers were advanced from idle to takeoff position, then returned to idle 6 seconds later. Reverse thrust was selected 8 seconds after that, and both thrust reversers deployed when commanded. Airbrakes, though armed, did not deploy upon touchdown; available data could not determine throttle position at touchdown or why airbrakes did not deploy.
Examination and Performance Data
Examination of aircraft systems found no preimpact mechanical malfunctions with wheel brakes or other systems. Landing distance data indicated the aircraft required about 2,551 feet to stop at its weight in the prevailing conditions. With 2,680 feet of runway remaining, uneventful stopping or a go-around was possible with appropriate deceleration device use. The standard landing procedure called for thrust reverser activation after nosegear touchdown followed by braking as necessary; however, the PIC only applied brakes. No callouts for ground spoiler or reverse thrust deployment were made. The PIC subsequently stated intent to go around, but the SIC indicated it was too late. The PIC's delayed decision resulted in an approximately 22-second delay in thrust reverser activation, causing the overrun. Neither pilot activated the emergency brake, as would be required for a perceived brake failure. Seat examination revealed a forward-facing seat installed in an aft-facing position and an aft-facing seat installed forward. The ejected seat's shear plungers were found in the raised position; proper installation would have them lowered into the seat track. The improper installation likely caused the seat to separate and exacerbate the passenger's injuries.
Probable Cause
The pilot in command's failure to follow normal landing procedures (placing engines into reverse thrust first and then brake), his delayed decision to continue the landing or go-around, and the flight crew's failure to follow emergency procedures once a perceived loss of brakes occurred. Contributing to the seriousness of the passenger's injury was the improper securing of the passenger seat by maintenance personnel.