GB2376038A

GB2376038A - Ultraviolet marking system for aiding aircraft take off, landing and manoeuvring on the ground

Info

Publication number: GB2376038A
Application number: GB0211741A
Authority: GB
Inventors: George Lowthian Edgecombe; Leonard Henry Townsend; Trevor George Wicks
Original assignee: Alstom SA
Current assignee: Alstom SA
Priority date: 2001-05-25
Filing date: 2002-05-22
Publication date: 2002-12-04
Anticipated expiration: 2022-05-22
Also published as: GB0211741D0; GB0410352D0; GB0112775D0; GB2376038B

Abstract

The ultraviolet marking system, particularly for use on aircraft carriers and other navel aircraft carrying vessels, comprises a combination of UV fluorescent markings and at least one diffused UV light source positioned to illuminate the markings so as to aid take off, landing etc. The markings are in the form of an adherent coating comprising a mixture of a transparent or translucent binder chosen to bond to a surface to which the coating is applied and at least one UV fluorescent material dispersed in the binder and which has a rapid fading of fluorescence after extinguishing of the UV light. The UV fluorescent material may comprise zinc sulphide and/or cadmium sulphide or may comprise lithopone. The markings may be made on horizontal or vertical surfaces or on posts or poles. The binder may be chosen from any of the following groups of organic compounds: epoxies, polysiloxanes, vinyls, acrylics and combinations thereof. A top layer of small glass beads may be partly embedded in the binder/pigment mixture.

Description

FLUORESCENT MARKINGS This invention relates to fluorescent markings.

It is known to provide roads surfaces, parking areas and traffic signs with traffic control and warning markings which fluoresce when illuminated with ultraviolet (UV) light.

It is an object of the present invention to facilitate manoeuvring of aircraft at night.

According to the present invention, aircraft manoeuvring and/or parking areas and/or surfaces accessory thereto are provided with a combination of UV fluorescent markings and at least one diffused UV light source positioned to illuminate the markings, thereby to aid take off, landing and marshalling of air traffic at night, the fluorescent markings being in the form of an adherent coating comprising a mixture of a transparent or translucent binder chosen to bond to a surface to which the coating is applied and at least one UV fluorescent material dispersed in the binder, the at least one UV fluorescent material having a rapid fading of fluorescence after extinguishing of the UV light source.

Zinc sulphide and/or cadmium sulphide may be utilised in or as constituents of the UV fluorescent material but a more preferred fluorescent material may comprise lithopone.

A particularly advantageous use of the invention is in the context of naval aircraft, such as the flight deck and/or landing pad of an aircraft carrier or other ship. The effect of the markings is to enhance safety and ease of manoeuvring of aircraft by giving pilots additional depth of vision, particularly during landing and takeoff The use of fluorescent markings without visible illumination of the ship during manoeuvring on deck, takeoff and landing, followed by rapid cessation of fluorescence after extinguishing of the UV source, is of particular advantage during covert operations.

The UV fluorescent markings may comprise line and/or spot and/or area markings The line markings may be broken up longitudinally into dashes or dots and the spot markings may be circular, square, polygonal, or any similar shape of limited area If desired, the line markings or spot markings may be used on vertical surfaces, such as short posts and/or poles (preferably flexible) alongside the manoeuvring (e. g. , runway) and/or parking areas, but preferably the line markings are used to outline the horizontal surfaces of manoeuvring and/or parking areas The short poles and/or posts should not stand sufficiently proud of the horizontal surfaces to present a hazard to aircraft manoeuvring thereon.

The fluorescent markings are applied in the form of a paint-like material, the binder being chosen from any of the following groups of organic compounds epoxies, polysiloxanes, vinyls, acrylics and combinations thereof Preferably, the coating further comprises a top layer comprising small glass beads (preferably exceeding 1 nun in diameter) partly embedded in the binder/pigment mixture to protect the coating from wear and to disperse the light emanating from the marking. Conveniently, the glass bead layer is added to the coating after application of the binder/pigment mixture to the surface to be marked and while the coating is still wet or tacky, i e. , not completely dry or cured.

The UV light source preferably emits light in the wavelength range 315-400nm, particularly 365nm.

Exemplary embodiments of the invention will now be described.

To facilitate the launch, recovery and marshalling of aircraft such as civil and military helicopters and fixed wing aircraft in darkness, the invention provides runways, landing pads, flight decks and aircraft parking areas with line, spot or area markings which fluoresce when illuminated with UV light The fluorescent markings will typically be provided for the following purposes

(a) To outline or otherwise define areas having different uses, such as helicopter landing pads, takeoff areas, landing areas, marshalling areas and ground-crew areas. For example, in addition to providing a flight deck ab initia with UV fluorescent markings which also serve in a non-fluorescent mode during daylight, UV fluorescent markings may be produced by overpainting existing non- fluorescent markings with coatings containing fluorescent pigments, or by removing existing non-fluorescent markings and substituting fluorescent markings, or by providing fluorescent markings alongside non-fluorescent markings as a supplement thereto.

(b) To serve as landing approach or takeoff guidance markings for aircraft, the fluorescent markings being illuminated by UV flood lamps.

(c) For application to raised horizontal or vertically extending surfaces, such as superstructure, railings, warning signs, posts or poles, etc For example, in the case of minor airfields subject to snow or ice conditions, such that the normal inset airfield lighting may be obscured, the invention may be utilised in the form of, e. g. , metallic or plastic discs (or other suitable shapes), to which the UV fluorescent coating has been applied, the discs being attached to flexible poles or posts along the edge of the runway or other manoeuvring area and illuminated by UV floodlights or spotlights, which also may be on flexible mountings if necessary. The poles or posts and the floodlights or spotlights should of course be sufficiently proud of the runway or other surface to avoid ice and snow cover, but not high enough to present a hazard to aircraft.

The fluorescent markings typically consist of an adherent coating or"paint"comprising a UV fluorescent pigment material mixed with a binder chosen to bond to a surface to which the paint is to be applied. The pigment material may comprise a single pigment or a mixture of two or more different pigments.

For application to surfaces subject to wear, or exposed to severe weather, e. g., as an area, line or spot marking for a flight deck, the binder should be, e. g., an epoxy resin, a

polysiloxane, or a suitable co-polymer such as an epoxy-acrylic copolymer In any case, to extend the life of the coating and to improve light dispersion from its surface, a top layer of small glass beads, of the type normally incorporated in the resin coatings used for road markings or road signs, should be pressed into the surface of the binder/pigment mixture after it has been applied to the surface to be marked and before it has completely set, so that the glass beads are held partly embedded and partly protruding from the top face of the binder/pigment mixture. We prefer that the glass beads, although small, have a diameter greater than one millimetre.

Those skilled in the art will recognise that some UV fluorescent pigments remain fluorescent for a time extending perhaps to hours after the source of stimulating UV radiation is extinguished, whereas the fluorescence of other pigments fades rapidly after extinguishing of the UV light source, such that they have little or no residual fluorescence. The latter type of pigments are used for the invention and such pigments may comprise zinc sulphide or cadmium sulphide or other more complex luminescent pigments, such as lithopone. The latter is a mixture of zinc sulphide and barium sulphate, used e. g. , in television screens. With the addition of suitable colorants, the coating may be constituted to fluoresce in different colours.

It is important to provide sufficient sources and power of UV illumination to enable sufficiently strong fluorescence to be excited from the UV fluorescent pigments used in the markings. Such sources may be floodlamps for wide area illumination, or else more localised directed spot illumination, e. g. for warning signs. In particular, we have found that a UV lamp emitting light in a wavelength range which borders on visible light, particularly 315-400 nanometers, and particularly 365nm, is important for good excitation when used in combination with the above-mentioned pigments and may be, for example, a Philips MPXL-DUV35 lamp, which produces a high UV intensity at this wavelength. The UV light emitted by the lamp should be diffused for even illumination of the surfaces it is intended to illuminate.

Claims

CLAIMS 1. On an aircraft manoeuvring and/or parking area and/or surfaces accessory thereto, a combination of TN fluorescent markings and at least one diffused UV light source positioned to illuminate the markings, thereby to aid take off, landing and marshalling of air traffic at night, the fluorescent markings being in the form of an adherent coating comprising a mixture of a transparent or translucent binder chosen to bond to a surface to which the coating is applied and at least one TN fluorescent material dispersed in the binder, the at least one UV fluorescent material having a rapid fading of fluorescence after extinguishing of the UV light source.
2. The combination of claim 1, in which the UV fluorescent material comprises zinc sulphide and/or cadmium sulphide.
3. The combination of claim 1, in which the UV fluorescent material comprises lithopone.
4. The combination of any preceding claim, in which the aircraft manoeuvring and/or parking areas and/or surfaces accessory thereto are provided on a flight deck and/or a landing pad of a ship.
5. The combination of any preceding claim, in which the UV fluorescent markings comprise line and/or spot and/or area markings
6 The combination of claim 5, in which at least some of the line markings are broken up longitudinally into dashes or dots.
7. The combination of claim 5 or claim 6, in which the spot markings are circular, and/or square, and/or polygonal, and/or any similar shape of limited area.

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8. The combination of any preceding claim in which the line markings and/or spot markings are provided on vertical surfaces
9 The combination of claim 8, in which the vertical surfaces comprise short posts and/or poles alongside manoeuvring and/or parking areas.
10 The combination of claim 9, in which the short posts and/or poles are flexible.
11. The combination of any preceding claim, in which the binder is chosen from any of the following groups of organic compounds. epoxies, polysiloxanes, vinyls, acrylics and combinations thereof
12. The combination of any preceding claim, in which the coating further comprises a top layer comprising small glass beads partly embedded in the binder/pigment mixture.
13. The combination of claim 12, in which the glass beads exceed one millimetre in diameter.
14. The combination of claim 12 or claim 13, in which the glass bead layer has been added to the coating after application of the binder/pigment mixture to the surface to be marked and while the coating is not completely dry or cured.
15 The combination of any preceding claim, in which the UV light source is adapted to emit light in a UV wavelength range which borders on visible light.
16. The combination of claim 15, in which the UV light source is adapted to emit light in the wavelength range 315-400 nanometers.

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17. The combination of claim 16, in which the UV light source is adapted to emit light at a wavelength of 365 nanometers
18. A combination of aircraft manoeuvring and/or parking areas and/or surfaces accessory thereto provided with a combination ofUV fluorescent markings and at least one diffused UV light source positioned to illuminate the markings, substantially as described herein.