Mosquito DH 98 HR621

The FB V1 aircraft were sent out from the UK at a later date to the Highball aircraft so as to conserve flying hours on the converted B Mk 1V aircraft and the difficulty of landing the top secret Highball aircraft at another base. HR621 along with all other Squadron aircraft were sold in the late 1940's, with HR621 going to a farmer at Tomingley NSW.

The Museum acquired the very incomplete and deteriorated remains of the aircraft in May 1968. The restoration of HR621 is the largest restoration project carried out by the Museum. The parts in the restoration have come from the recovered remains of some eight 618 Squadron aircraft. The project is now well advanced. The intention is to have HR621 as a static complete aircraft with all internal cockpit and fuselage fittings and equipment installed and primary flight control system functional..

Following the success of 617 Squadron raids on German dams the concept of a smaller Barnes Wallis "bouncing bomb" delivered by a Mosquito was developed. B Mk IV bombers were extensively converted in the bomb bay area with an external fitting on fuselage between bulkhead 5 and an additional bulkhead 5A to attach an arrestor hook. 618 Squadron did not see any service in the Pacific war apparently due to the concern that the top-secret highball could be copied by the Japanese and then used against allied shipping. There was also apparently rivalry within the allies with the Americans seeing the Pacific as their war and thus did not want a British design upstaging their efforts to defeat Japan.