Month in the Patent Office

An engine installation consists of a main turbo‐jet unit 11, preferably of the by‐pass type, in the tail of the fuselage, and a series of slave turbine units 14 mounted in the flaps 13, whereby direct lift assisting in the control of ascent or descent may be obtained upon lowering the flaps, the maximum angle of deflexion of which may be approximately 90 deg. Fuel for the slave units 14 is supplied by pumps, driven by the main unit 11, through transverse tubes 21, forming the hinges for the flaps. Air is supplied through ducts 19 opening into the leading edges of the wings, except when the flaps are lowered, when it enters through the gaps opened between the upper surfaces of the wings and flaps. Instead of being adjustable one or more slave units may be fixed in the wing and directed downwardly, such unit(s) only being used during ascent or descent. Lateral control of the aircraft, when it is supported by jet thrust, may be obtained by differential adjustment of the fuel supply to the port and starboard sets of slave units 14. Longitudinal control may be provided by deflexion of the exhaust from the main unit 11, or by fuel control or angular adjustment of one or more fixed or pivotally mounted additional slave units in the tail unit of the aircraft. Some or all of the slave units 14 may be cut out during low speed flight to give increased fuel economy when cruising.