 It was powered by an Alvis Leonides radial piston engine that drove a lift fan, and using ducted air generated by the fan for propulsion.Forward and backward thrust was provided via a set of longitudinal ducts which were fixed to either side of the craft's deck and supplied with air from the engine housed within the cylindrical centre piece to which they were attached.The outer jet was installed upon closely mounted 2-foot-long ribs and running to within four inches of the inner jet; the inclined surface between the inner and outer jets was plated and reinforced against the impact of waves or inadvertent ditching.