Gear actuation on the Beau was hydraulic, with a pump on each engine, not pneumatic. Hydraulics were turned off when airborne to avoid overheating the pumps. Pneumatics were confined to brakes, fuel jettison, guns and landing flares from a pump on the starboard engine. With no hydraulic pressure Pontius Navigator's theory re inflated tyres sounds correct. Uplocks must have suffered damage in the ditching.