Vertical and short take-off and landing aircraft

In one aspect, the aircraft 10 comprises an airframe having a forward end 20, an aft end 22, a top and bottom, a power plant 46 (such as an internal combustion engine, gas turbine engine, electric motor, hydrogen fuelled engine, or a hybrid motor) at least two propellers 44, driven by the power plant, and at least two sets 40, 42 of counter-rotatable fans for providing lift. Each fan set may comprise upper and lower face gears 64, 66 driven by means of a pinion 82 on a drive shaft 58, 60 driven by the power plant 46 through a transfer gearbox 54 also having upper and lower face gears. For control purposes the aircraft is provided with ailerons 28, flaps 30, and elevators 32, and the blades of the fan sets and the propellers may be variable in pitch and may each comprise a shape-memory alloy or a composite matrix having embedded piezoelectric smart actuator fibres. Separately claimed are a flight control system, methods for controlling the aircraft in flight and an aircraft having a ducted ring fan, a fan shaft connecting the power plant to the ring fan, a propeller, and a propeller shaft connecting the power plant to the propeller.