Patent GB-151041-A (GB)
Title: Improvements relating to the control of aerial traffic
IPC: B64F1/20
Filed: 1919-04-29
Abstract: 151,041. McKenzie, Holland, & Westinghouse Power Signal Co., and Peter, L. H. April 29, 1919. Indicators on landing-places.-A signalling-system for the control of aircraft arriving at or departing from an aerodrome comprises landing, take-off, and circuit direction signals, and signals indicating the direction of the wind, which are effected by a system of locking and indication to prevent conflicting signals from being given. Fig. 1 shows an arrangement of lights on an aerodrome for use at night. The ground is marked by a series of boundary lights 3 and is provided with a series of search-lights 4-9, two adjacent ones of which are automatically lit to illuminate a track for aircraft alighting and a track for aircraft taking off in accordance with the direction of the prevailing wind. The search-lights may be controlled by a switch operated by a wind vane, and each light has a motor which slews the light in the appropriate direction according as the companion light is at one side or the other. For this purpose, the motors may each have two field windings adapted for opposite directions of rotation, the two windings being in circuit respectively with the lights to either side, and the armature being in circuit with its own light. Lamps 10, 11 indicate safety or danger for alighting, similar lamps 12, 13 are for taking off, and lamps 14, 15 are for indicating whether a right or left hand circuit is to be taken. There is also a lighthouse 16. The lamps 10-15 are operated bv three switches controlling relays, each of the armatures of which completes a circuit through one or other of its corresponding pair of lamps according as this armature is attracted or not. Each switch is provided with a locking-device controlled by the relay so that the opening movement of the switch cannot be completed until the corresponding signal has been made. Any failure of the circuits results in the armatures cutting-in the danger signals and the switch-locking devices. By means of switches controlled by the armatures of solenoids in circuit respectively with the boundary lights 3 and search-lights 4 - - 9, the operation of the lamps 10 - - 15 is made dependent on the proper operation of the lights 3 and 4 - - 9. A modification is described in which a single movable pair of search-lights is provided for the landing and take-off tracks, and the switches for controlling the landing and take-off lamps have their locking- devices cross-connected so that the operation of one is dependent on the position of the other. Another modification is described in which pairs of landing and take-off lamps are provided near each of the search-lights 4 - - 9 shown in Fig. 1. The systems at two or more adjacent aerodromes may also be interlocked with a view to preventing collisions. For example, the landing and take-off lights may be so interlocked that permission to land at one aerodrome and to take-off at another cannot he simultaneously given. The circuit lights may also be controlled according to whether the wind is parallel or at right-angles to the line joining two adjacent aerodromes. Means for indicating the setting of all the signals at some point remote from the control point may also be provided.