Optical: systems and elements – Signal reflector – 3-corner retroreflective
Reexamination Certificate
2000-06-23
2001-09-25
Phan, James (Department: 2872)
Optical: systems and elements
Signal reflector
3-corner retroreflective
C359S527000, C340S947000, C340S953000
Reexamination Certificate
active
06293678
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates primarily to aircraft landing approach and guidance systems, and more particularly, to an aircraft approach landing system using passive retroreflective panels strategically placed along both sides of a landing strip or runway.
BACKGROUND OF THE INVENTION
Aids to navigation are a critical element in the air traffic control system. The navigation function needs to be satisfied by a variety of technologies to supplement destination finding when weather or ambient light limits visual references.
The earliest navigation aids were lighted beacons placed along the ground; these suffered obvious problems during adverse weather and were replaced by radio direction-finding equipment. The radio technologies are able to transmit the heading and distance to an intended destination.
These aircraft-mounted technologies are supplemented by air route surveillance radar, which monitors aircraft within each designated sector of the air route traffic control system. The radar-based systems form the backbone of the navigation aids for privately owned aircraft and small passenger-carrying planes. Major commercial jets are now supplied with inertial navigation units, which allow an aircraft to independently navigate to a destination. A computer and gyroscope are used to sense direction and, with speed sensors, track direction and distance to the destination. The navigation units can fly virtually automatically until in the vicinity of an airport—at which time the pilot and controller interact to safely control the landing.
Only the simplest airfields are designed for operations conducted under visual meteorological conditions (VMC). These facilities operate only in daylight and the only guidance they are required to offer is a painted runway centerline and large painted numbers indicating the magnetic bearing of the runway. Larger commercial airports, on the other hand, must also operate in the hours of darkness and under instrument meteorological conditions (IMC), when horizontal visibility is 650 yards or less and the cloud base (or “decision height”) is 65 yards or lower. In order to assist aircraft in approaches and takeoffs and in maneuvering on the ground, such airports are equipped with sophisticated radio navigational aids (navaids) and visual aids in the form of lighting and marking.
A Visual Assault Zone Marker Panel (VAMP), Model C, is typically used for C-17 operations. The “C” Model is the high velocity VAMP designed for use with aircraft that generate a maximum take-off blast (from either a jet or prop) that is greater than 200 mph. These VAMP's are constructed of a cerise (420 denier nylon) fabric panel, whose dimensions are 17 inches high by 72 inches long. This panel is reinforced around its entire outer edge by a two-inch-wide (1000# test) nylon webbing that is sewn into the colored panel material. Three 2-inch webbing loops are evenly spaced and sewn to each of the 17-inch sides. Additionally, there are two 20-inch webbing stiffeners evenly opened along the bottom edge of the fabric panel. There is a 0.3125-inch inside diameter (ID) brass-coated steel grommet through which bungee cords are used to tether to aluminum stakes.
Disclosed are several visual aircraft runway panels that have been in use for several years. Examples of such prior art are shown in the examples that follow.
U.S. Pat. No. 5,208,601, granted Nov. 4, 1993, to G. E. Hart, discloses an all-weather precision landing system for aircraft in remote areas. This all-weather aircraft landing system includes a plurality of ground based passive 90 degree dihedral reflectors for producing two-bounce reflected signals without ground reflections, and an airborne radar system.
U.S. Pat. No. 5,136,288, granted Aug. 4, 1992, to L. M. Briatte, relates to a method and an installation providing an aircraft with alignment guidance during the approach stage. At least three flashing lights are disposed on either side of the runway and directed towards an approaching aircraft. The beam direction and timing of the light flashes are such that the pilot of the aircraft lying above the axis of the runway sees the two lights closest to the runway flash simultaneously.
U.S. Pat. No. 4,210,930, granted Jul. 1, 1980, to R. D. Henry, discloses an aircraft approach system with simulated display of runway lights and glide slope indicator, using an airborne image camera, its respective scan plate and an image cathode ray tube (CRT) display.
The prior art recited above does not teach of the novel advantages that are found in the present invention. Several teach of navigational aids that use sophisticated electronic equipment, such as CRT presentations, whereas some use fluorescent fabric panels as visual markers. Still others use a series of flashing lights to indicate the central axis of the landing strip.
SUMMARY OF THE INVENTION
The present invention relates primarily to a novel aircraft landing approach and guidance system using passive retroreflective panels strategically placed along both sides of an airport runway or landing strip for defining underrun, touchdown, landing and overrun zones. Four pairs of panels, where each pair is laterally spaced 6 feet apart, define the touchdown landing zone by being placed in each corner of the zone. Singly placed retroreflective panels, symmetrically placed further down on both sides of the runway, are mounted at a distance between them that does not exceed 1000 feet, but is greater than 500 feet apart.
Each panel is made from a sheet of aluminum, to which is adhered on both front and rear surfaces, fluorescent orange retroreflective sheeting. The panel is subsequently bolted to a plurality of upright mounting stanchions, preferably seven stanchions. At the midpoint of each stanchion, approximately at the base of each panel, are frangible fittings. Attached to the bottom of the frangible fittings are the spaded tines that are used to secure and maintain the placement of each runway panel.
Applying the gelatinous retroreflective sheeting to both sides of the aluminum panel permits the panels to be used on runway systems that are bi-directional, where the landing approach can be made from opposite directions. To accomplish a landing from opposite directions, the number of retroreflective panels is twice of that needed for a single approach landing strip, because of the symmetry in the panel placement locations.
In a second preferred embodiment of the present invention, the resinous retroreflective sheeting is applied only to the front surface of the runway panel. In this configuration, this single sided panel can be used in airstrip landing systems where the approach can be made from one direction only, thereby reducing the number of panels required to one-half, because of the non-symmetrical runway arrangement.
Accordingly, it is therefore an object of the present invention to provide a novel aircraft approach landing system using passive retroreflective panels strategically placed along both sides of a landing strip.
It is another object of the present invention to provide a novel aircraft approach landing system using passive retroreflective panels strategically placed along both sides of a landing strip having color-coded panel markers that divide the airport runway into a plurality of aircraft approach and landing zones to indicate the touchdown zone and subsequently, the remainder of the landing strip.
It is still another object of the present invention to provide a novel aircraft approach landing system using passive retroreflective panels strategically placed along both sides of a landing strip, comprising marker panels having rigid aluminum sheets covered with a wide angle prismatic lens retroreflective sheeting.
It is still yet another object of the present invention to provide a novel aircraft approach landing system using passive retroreflective panels strategically placed along both sides of a landing strip, comprising marker panels of less than 19 inches in height after being installed.
An additional object of the present inven
Phan James
Taddeo Joseph H.
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