The first prototype Victor B.2, serial number "XH668" made its maiden flight on 20 February 1959. It had flown 100 hours by 20 August 1959, when, while high-altitude engine tests were being carried out by the Aeroplane and Armament Experimental Establishment (A&AEE), it disappeared from radar screens, crashing into the sea off the coast of Pembrokeshire. An extensive search operation was initiated to locate and salvage the wreckage of "XH668" to determine the cause of the crash. It took until November 1960 to recover most of the aircraft; the accident investigation concluded that the starboard pitot head had failed inflight, causing the flight control system to force the aircraft into an unrecoverable dive. Only minor changes were needed to resolve this problem, allowing the Victor B.2 to enter service in February 1962.