The Premier 1 departed on a flight from Humberside to Dublin with the pilot and six passengers on board. Once airborne the pilot attempted to raise the landing gear, but although the control handle moved the landing gear remained in the fully extended position with three green lights illuminated on the landing gear indicator. The pilot attempted to re-cycle the landing gear but without success; later he noticed that he also had indications of LIFT DUMP FAIL and ANTI SKID FAIL. He diverted to Farnborough. After touchdown the pilot attempted to deploy the lift dump system but, as expected, the lift dump spoilers failed to extend. After discussing the problem with the aircraft’s maintenance organisation, the aircraft was flown to Blackbushe for further technical investigation. After landing on runway 26 (4400 feet long) the aircraft left the runway, struck a series of obstructions and was destroyed. The support bracket for the right main landing gear weight-on-wheels switch was found to have sustained a pre-impact failure which accounted for the indications reported by the pilot.