BAC Inc.

Dassault Falcon 10

Because of the failure of the thrust reverser relay circuit board, the thrust reversers failed to deploy when selected by the pilot. Because the reversers failed to deploy, the 'reversers in transition' lights, and the 'reversers deployed' lights did not illuminate. Even though the aircraft flight manual warns against moving the reverser throttle levers into the power range without the illumination of these lights, the pilot did so anyway. The pilot continued to select reverse power even after the activation of the throttle mismatch warning horn, resulting in an increase in forward thrust while attempting to stop. During this sequence of events the second-in-command moved the parking brake lever to full override, locking the main wheel brakes and overriding the antiskid system.