US2691150A

US2691150A - Slopeline approach light system

Info

Publication number: US2691150A
Application number: US418793A
Authority: US
Inventors: James E Davis
Original assignee: Individual
Current assignee: Individual
Priority date: 1954-03-25
Filing date: 1954-03-25
Publication date: 1954-10-05
Anticipated expiration: 1971-10-05

Description

Get. 5, 1954 DAV|$ 2,691,150

SLOPELINE APPROACH LIGHT SYSTEM Filed March 25, 1954 2 Sheeis-Sheet 1 5 O l5 0 0 o l4 0 g fi FIG. 3

/ INVENTOR a 4 JAMES E DAV/S Get. 5, 1954 J. E. DAVIS 2,691,150

SLOPELINE APPROACH LIGHT SYSTEM INVENT OR JAMES E DA W5 BY win/W ATTRNEYs Patented Oct. 5, 1954 UNITED STATES PATENT OFFICE (Granted under Title 2365,)U. S. Code (1952),

6 Claims.

The invention described herein may be manu factured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

The present invention relates to a slopeline approach light system and more particularly to slopeline approach light system which incorporates single dimension ground-plane and direction-of-flight elements into the three dimensional elevation-and-centerline-deviation and horizontal-and-distance elements.

The standard slopeline approach light system consists of two converging rows of slopeline light units lying to the right and left of the runway axis, beginning 3000 feet from the runway threshold and ending at a point 200-300 feet therefrom. The point of convergence of the two rows occurs near the ideal touchdown point on the runway centerline. The individual slopeline units are mounted in vertical planes perpendicular to the runway axis and are spaced at 100 foot intervals. The major dimension of each unit slopes toward the ideal glide path at an angle of 45 degrees with respect to the plane of the runway. The transverse location of the individual units is determined by the intersection of the two 45 degree planes, which pass through the ideal glide path, with the local terrain. Three transverse bars were added to the original slope line system to provide additional horizontal reference and to establish three check points to inform the pilot of his distance from the runway threshold.

The disadvantage of the standard system is that neither the original system nor the transverse bar additions provide a fixed ground plane with reference to the individual slope units, the only fixed reference for the pilot being an imaginary line he draws from the base of one unit to the base of the next unit. The series of slope units tend to break up when the pilot is off of the ideal glide path and becomes confusing particularly during low visibility approaches when he has only a few units of one side in view and is off the ideal glide path. Under these conditions there is not enough ground plane and direction of flight information present and the pilot may make the wrong correction, thereby necessitating a new approach attempt. In the standard system there is no fixed reference for the slopeline units to oscillate around or pivot from. This leaves the pilot with the impression of a series of objects in space with no tie point to indicate a ground plane or solid substance ahead on which to land the airplane.

The present invention overcomes the disadvantages of the prior known systems by incorporating single dimension ground-plane and direction-of-flight elements into the three dimensional elevation-andcenterline-deviation and horizontal-and-distance elements. This is accomplished by increasing the spacing between adjacent slope units and positioning individual lamp light units at short intervals along the ground plane therebetween, so as to form a straight line of light units extending from the base of one slope unit away from the threshold approximately half way towards the next slope unit. The single light units lie in the ground plane and provide artificial ground-plane and direction-offlight guidance even though the pilot may not readily interpret the elevation and lateral guidance afiorded by the slope units. The lines of light units provide fixed elements in the system that the top ends of the slope units can oscillate around and the bottom ends can pivot from, thus giving the pilot a sensation of substance rather than merely something in space.

An object of the present invention is the provision of a slopeline approach light system which includes tie points for the slopeline units.

Another object is to provide direction of flight guidance in a slopeline approach light system.

A further object of the invention is the provision of well defined ground plane guidance in a slopeline approach light system.

An additional object of the present invention is the provision of a three dimensional slopeline aproach light system which embodies single dimension ground-plane and line-of-fiight elements.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

Fig. 1 is a plan view of the threshold of a runway and an approach light system according to the present invention.

Fig. 2 is an elevation view of the system of Fig. 1.

Fig. 3 is an elevation view of a slopeline light Fig. 1 shows the threshold of a runway H and two rows of approach lights 12 and I3 diverging away therefrom on either side of the runway centerline. Each of the rows l2 and [3 consists of alternately arranged 45 degree slopeline units I4 and groups of individual light units t5 and extends approximately 3000 feet from the runway threshold. The 45 degree slopeline units are spaced approximately 200 feet apart and each group of individual lights forms a line extending from the base of one slopeline unit away from the runway threshold approximately halfway to the next slopeline unit. Each group of individual lights usually consists of seven lights spaced'l5 feet apart, the first one of which is also positioned 15 feet from the base of a slopeline unit, the group of lights thus forms a line approximately 105 feet long. The spacing between individual lights or the number of individual lights in a group may be varied to satisfy the requirements of any individual approach area, but the individual lights of each group must all be positioned on a line extending between the bottom lamps of adjacent slopeline units.

Fig. 2 shows an elevation View of one line of approach lights in which the approach area on which the row is positioned is flat. In this view, the individual light units are all in the same horizontal plane with the bottom lamps of adjacent slopeline units. If the approach area were uneven and one slopeline unit at a higher elevation than the adjacent slopeline unit, the individual lights positioned therebetween would all be mounted so as to be in the plane joining the bottom lamps of adjacent slopeline units. If the difference in elevation between adjacent slopeline units exceeds approximately 5 feet it may be necessary to add additional lights to the group in order to retain the continuity of the system.

The 45 degree slopeline unit of Fig. 3 consists of a vertical upright It on which is secured a crosspiece H at an angle of 45 degrees with the horizontal. A plurality of lamps [S are spaced along the length of the crosspiece. The slopeline units are arranged in pairs, one in each row of lights, and the intersection of the extensions of the lines defined by the lamps on the crosspieces marks the location of the ideal glide path.

The groups of individual light units provide direction of flight and ground plane guidance which is not supplied by the slopeline units As shown in Figs. 4-7, this guidance does not depend upon the position of the approaching aircraft, but exists for all positions during an appreach. When the approaching aircraft is on the ideal glidepath, the groups of individual lights and the slopeline units merge into almost continuous straight rows. When the approaching aircraft is of; of the ideal glidepath, the rows of light units become segmented and each slopeline unit appears to pivot about its associated group of individual light units. The slopeline units point inwardly when the aircraft is high on centerline, Fig. i, and outwardly when the aircraft is low on centerline, Fig. 5. When the aircraft is not on the centerline and is high, Fig. 6, the farther row becomes segmented and the slopeline units of the nearer row point inwardly. As can be seen from 5, pilot low and to one side of the glidepath would see the slopeline units of the farther row point outwardly and those of the near row overlap the adjacent groups of individual lights. As can be seen from Figs. 4-7, the lines formed by the individual light units engine aircraft and they therefore provide two lines of approach lights for the pilot to follow even though he does not interpret the elevation guidance inherent in the slopeline units.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. An aircraft landing aid system including two straight rows of lighting elements converging towards the threshold of a landing strip, each of said rows comprising alternately positioned degree slopeline light units and lines of spaced single light units, each of said lines of single light units extending from the base of one slopeline unit away from the threshold approximately halfway to the next slopeline unit; whereby the lines of single light units provide fixed elements which the tops of the slopeline units oscillate around and the bottoms thereof pivot from.

2. An aircraft landing aid system including two straight rows of lighting elements converging towards the threshold of a landing strip, each of said rows comprising a plurality of 45 degree slopeline light units spaced at large intervals; a plurality of single light units spaced at short intervals positioned between each pair of slopeline units, said plurality of single light units forming a line extending from the base of one slopeline unit away from the threshold towards the next slopeline unit; whereby each line of single light units forms a fixed element about which the top of the associated slopeline unit can oscillate and from which the bottom thereof can pivot.

3. In an aircraft landing aid system including two straight rows of spaced 45 degree slopeline light units converging towards the threshold of landing strip, the improvement comprising a line of spaced single light units positioned between each pair of slopeline units, each line of single light units extending from the base of one slopeline unit away from the threshold approximately halfway to the next slopeline unit; whereby each line of single light units forms a fixed element about which the top of the associated slopeline unit oscillate and the bottom thereof can pivot.

4.. In a slopeline approach light system including two rows of 45 degree slopeline light units converging towards the threshold of a landing strip, the slopeline units of each row being spaced at large intervals, the improvement consisting of a plurality of single light units spaced at short intervals positioned between each pair of slopeline units, said plurality of single units forming a line extending from the base of one slopeline unit away from the threshold towards the next slopeline unit; whereby the lines of single units provide ground-plane and line-offiight guidance for an approaching aircraft.

5. A slopeline approach light system comprising two converging rows of alternately positioned 45 degree slopeline units and lines of single units, each of said lines comprising a plurality of relatively closely spaced single units, said slopeline units being spaced at twice the normal interval with each line of single units extending from the base of one slopeline unit in divergent fashion approximately halfway to the next slopeline unit; whereby each line of single units forms a fixed element about which the top of the associated 10 slopeline unit can oscillate and from which the bottom thereof can pivot.

6. In a standard slopeline approach light systerm including two convergent rows of 45 degree slopelinelight units with alternate slopeline units of each row removed, the improvement consisting of a plurality of relatively closely spaced single light imits positioned between each pair of slopeline units, each group of single units forming a line extending from the base of one slopeline unit in divergent fashion approximately halfway to the next slopeline unit; thereby providing ground-plane and line-of-flight guidance for an approaching aircraft.

N 0 references cited.