Abstract:
An aircraft wingtip device comprises illumination means arranged to project light onto interior and exterior surfaces of the wingtip device.

Description:
RELATED APPLICATIONS 
     The present application is based on, and claims priority from, British Application Number 1101437.0, filed Jan. 27, 2011, the disclosure of which is hereby incorporated by reference herein in its entirety. 
     CROSS-REFERENCES TO RELATED APPLICATIONS 
     Not applicable. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT 
     Not applicable. 
     INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention is concerned with an aircraft lighting device. More specifically, the present invention is concerned with an aircraft wingtip device and associated lighting arrangement for illumination of the inward and/or outward faces of the wingtip device. 
     2. Description of the Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98 
     Wingtip devices are becoming increasingly common on commercial aircraft. Aside from the reduction of lift induced drag caused by wingtip vortices, wingtip devices also offer a vertically oriented area of the aircraft on which to place advertising and logos which are visible by both the passengers (on the fuselage facing, or inward, side) and by third parties (on the opposite, or outward, side). 
     It is generally desirable to illuminate the surfaces of the wingtip device in poorly lit conditions, to improve visibility for passengers and passers-by. 
     Because wingtip devices are often designed into existing airframes, there is limited ability to integrate illumination devices into the wing itself in order to project onto the fuselage facing side of the wingtip device. As such, in dark conditions, the logo and/or advertising on the wingtip device is not visible. In addition, because there is no structure outboard of the wingtip device, there is no component on which a lighting arrangement can be placed in order to project onto that side either. 
     It will be noted that logos and advertising on the vertical tail faces are illuminated by lighting systems positioned on the horizontal tail stabilisers. Because the vertical tail was integrated into the original airframe design, provision for illumination is made when the aircraft is designed in the first place. This is often not the case for wingtip devices which are integrated into the airframe when it is redesigned or upgraded. Furthermore, the solutions used for vertical tail plane illumination are not suitable for wingtips, not least because there is no structure on which to mount the illumination device outboard of the wingtip devices. 
     It is an object of the present invention to provide an apparatus capable of illumination of both the inward and outward facing sides of a wingtip device. 
     BRIEF SUMMARY OF THE INVENTION 
     According to the present invention there is provided an aircraft wing tip device assembly comprising a wing tip device defining a first end for attachment to a part of an aircraft wing, a second, free end and a lighting device arranged to project light onto a face of the wing tip device from a location proximate the second end. 
     Advantageously, provision of a lighting device within the wingtip device itself allows for illumination to be provided without design changes to the airframe outside of the wingtip (e.g. the wing). 
     Preferably, the lighting device comprises a light source and a light emission region, in which the light source is positioned remote from the light emission region, and light is transmitted from the light source to the light emission region along a light path. 
     The light source may be connected to the light emission region by a fibre optic cable defining the light path. 
     Alternatively, the light source is arranged to project light towards the light emission region. 
     Preferably, the lighting device comprises a reflector assembly in the light path to direct light from the light source towards the light emission region. 
     Preferably, the reflector assembly is configured to reflect the light by a total of 160 to 200 degrees. 
     Preferably, the light source is positioned proximate the first end of the wing tip device. 
     Preferably, the lighting device comprises a light source proximate the second end. 
     Preferably, the lighting device comprises an LED. 
     Preferably, the lighting device is a self-contained, powered lighting module which is removably installed in the wing tip device. 
     Preferably, an aerodynamically shaped glazing unit. 
     Preferably, the wing tip device defines a protrusion of the face, which protrusion is configured such that light from the lighting device projects at least partially from the protrusion back onto the face. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       An example aircraft wingtip device assembly will now be described with reference to the accompanying figures in which: 
         FIG. 1  is a perspective view of an aircraft comprising an aircraft wingtip device assembly according to the present invention; 
         FIG. 2  is a front view of an aircraft wingtip device assembly in accordance with the present invention; 
         FIG. 3  is a section view through the aircraft wingtip device assembly of  FIG. 2 ; and 
         FIG. 4  is a section view through a second aircraft wingtip device assembly in accordance with the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Turning to  FIG. 1 , there is provided an aircraft  100  comprising a fuselage  102 , a left wing  104  and a right wing  106 . Each of the wings  104 ,  106  comprises a vertical wingtip device  108 ,  110  respectively. 
     Turning to  FIG. 2 , the left-hand wingtip device  108  is shown from the front of the aircraft  100 . 
     The wingtip device  108  comprises a first end  112  for attachment to the aircraft wing  104 . The wingtip device  108  further comprises a second end  114  which is free. A horizontal region  116  proximate the first end  112  transitions into a vertical region  118  extending to the second end  114  via a curved region  120 . The vertical region  118  has a fuselage facing or inward face  122  and an opposite outward face  124 , which faces away from the fuselage  102 . Aircraft logos and/or advertising are printed on the faces  122 ,  124 . 
     A first protrusion  126  which is generally hemispherical, projects from the inward face  122  proximate the second end  114  of the wingtip device  108 . A second protrusion  128  which is also generally hemispherical projects from the outward face  124  proximate the second end  114  and generally opposite the first protrusion  126 . The protrusions  126 ,  128  are at least partially glazed and are part of a lighting device (not shown) which projects light  130  back down the faces  122 ,  124  and generally inclined towards the faces  122 ,  124 . 
     Turning to  FIG. 3 , a first internal scheme for the lighting device is shown. 
     Referring to  FIG. 3 , a lighting device  132  comprises an electronics pack  134  comprising a power supply, a heat sink and control circuitry. An LED lamp array  136  is positioned above the electronics pack  134  and arranged to direct light  130  towards a prism  138 . The prism  138  is arranged to split and reflect the light  130  through 90 degrees onto a first mirror  140  and a second mirror  142 , which mirrors protect the light  130  back down in the general direction of the LED lamp arrangement  136 . The minors  140 ,  142  are positioned partially within the first protrusion  126  and the second protrusion  128  respectively. 
     Either of the protrusions  126 ,  128  comprises a quarter-spherical glazing portion  144 ,  146  respectively such that light can pass through. The glazing portions  144 ,  146  form the bottom part of the protrusions  126 ,  128  and allow light to be directed from the mirrors  140 ,  142  down towards the surfaces  122 ,  144  of the wingtip device  108 . 
     It will be noted that the electronics pack  134  and the LED lamp arrangement  136  can be positioned at an appropriate point within the wingtip device  108  where the internal structure allows. In fact, they can be positioned proximate the first end  112  if desired. 
     Turning to  FIG. 4 , there is shown an alternative lighting device  150  installed in the wingtip device  108 . Similar components are numbered identically. The lighting device  150  comprises an electronics pack  152  positioned remote from the second end  114  of the wingtip device  108 . An LED lighting array  154  is connected to a first fibre optic cable  156  and a second fibre optic cable  158 . The cables  156 ,  158  are passed up through the body of the wingtip device  108  and are connected at their other ends to light heads  160 ,  162 . The light heads  160 ,  162  are arranged to project downwardly through the glazing  144 ,  146  back towards the surfaces  122 ,  124 . 
     It will be noted that because fibre optic cables are used, the electronics pack  152  and the LEDs  154  can be positioned remote from the second end  114  so as not to get in the way of any structural components within the wingtip device  108 .