GB444194A - Improvements in or relating to navigation aiding wireless systems - Google Patents

Abstract

444,194. Directive wireless signalling. TELEFUNKEN GES. FUR DRAHTLOSE TELEGRAPHIE, 12, Hallesches Ufer, Berlin. Sept. 14, 1934, No. 26460. Convention date, Oct. 11, 1933. [Class 40 (v)] In a radio navigational system for assisting aeroplanes to land under conditions of poor visibility, the landing beam L, Fig. 2, radiated from the transmitter S is traversed by two vertical beams from transmitters V, H to notify the pilot of his height and distance from the aerodrome. The arrangement is distinguished from that disclosed in Specification 377,624, where a " zero " indication is given. As the landing-line L may be " swung " to right or left of a central position, i.e. between the limits Z<11>, Z, Z<1> in Fig. 3, the vertical beams from the transmitters H, V are similarly swung so that they cut the landing line at equal heights h<11>v, hv, h<1>v. The modulation signal on the beam V energizes a valve relay CV, Fig. 5, on the aeroplane which operates a drop-indicator RV, and through a holding relay ev, maintains it in position. The tone frequency from the second beam transmitter H similarly operates a drop-indicator Rh, the arrangement preferably being such that the second relay can only be operated in sequence after the first.