Abstract:
Multi-mode exterior lighting architectures for aircraft are provided. In accordance with an exemplary embodiment, an illumination system for illuminating a plurality of positions exterior to an aircraft includes a first light assembly coupled to the aircraft. The first light assembly is configured to produce a first light beam and direct the first light beam at a first position during a first operational mode and at a second position during a second operational mode. A second light assembly also is coupled to the aircraft and is configured to produce a second light beam and direct the second light beam at a third position during the first operational mode and at a fourth position during the second operational mode.

Description:
TECHNICAL FIELD 
       [0001]    The embodiments described herein generally relate to exterior lighting for aircraft, and more particularly relate to multi-mode exterior lighting architectures for airplanes. 
       BACKGROUND 
       [0002]    Airplanes make use of multiple types and locations of high intensity exterior lighting systems for various operational modes. The lighting architecture used on an airplane depends on the size of the airplane, the space available for light assembly placement, and the type of light sources to be used. Light sources typically used for exterior applications on airplanes include high intensity discharge (HID), incandescent, halogen incandescent, light emitting diode (LED), and sealed beam parabolic aluminized reflector (or “PAR”) lamps of various sizes. 
         [0003]    Generally, at least one of three different types of lighting systems are used on airplanes. An example of a light architecture commonly used on airplanes is illustrated in  FIGS. 1 and 2 . Taxi light systems  102  are used on the ground to illuminate the pavement to the front of an airplane body  100 . Taxi light systems typically include two high intensity light sources that are mounted on the nose gear  110  of the airplane, either in a fixed forward mount or on a movable portion of the nose gear so that, when the front nose wheels are turned in a particular direction, the light sources also are turned in that direction. Runway turnoff light systems  104  typically include two light sources that are each fixedly mounted on the leading edge of the wing root (also referred to as the strakelet)  112 , that is, the portion of a wing  114  adjacent to the intersection of the wing and the fuselage  116 , and point off from either side of the airplane to illuminate the runway and taxiways to the side during taxing. Runway turnoff lights are helpful during situations where the aircraft is being taxied during a turn, such as from the runway onto a taxiway. Certain larger airplanes, such as the Boeing® 747, may have runway turnoff light assemblies mounted on the nose gear. Landing light systems  106  illuminate the runway during takeoffs and landings. The systems typically include four high intensity light sources, with two light sources mounted on the leading edge of each wing root adjacent to the runway turnoff lights. Two light sources direct light forward toward the front of the airplane and two light assemblies direct light downward toward the front of the airplane. The lights are oriented to provide adequate runway illumination during approach and while the aircraft is flaring just before touchdown. An airplane may also have a wing illumination light assembly  108  mounted on each side of the fuselage to illuminate the wings for ice inspection. Taxi camera lighting systems, exterior cargo lighting systems, logo lighting systems, and the like may also be used. 
         [0004]    Present day airplane lighting system architectures, however, suffer from several drawbacks. Typically, the above-described lighting systems each have a dedicated function. However, such single-function architecture is space and weight inefficient. Because the lighting systems perform only one function, they are used only for a short period of the airplane flight. For example, the landing lights typically are used only during take-offs and landings. During the remainder of the flight, the lighting systems are extra weight. An ongoing effort to decrease airplane weight, and thus increase fuel efficiency, makes a reduction in airplane lighting systems highly desirable. 
         [0005]    In addition, it is difficult to design all the necessary lighting systems into smaller airplanes. Typically, light assemblies cannot be positioned on control surfaces, such as on the flaps of airplane wings. In addition, light assemblies cannot be positioned where they will interfere with the laminar flow of air over the airplane&#39;s surfaces. Retractable lighting systems mounted on the wings or within the fuselage have been used to overcome the design challenges. However, retractable lights, when deployed, face into the air stream. Vibration along with exposure to the elements and impact damage result in very low reliability of retractable lighting assemblies. 
         [0006]    Further, designing the necessary lighting systems into small and large airplanes becomes difficult when new lighting technology is used. For example, one new technology considered for use on airplanes is high intensity discharge (HID) light sources, which are more efficient and have a longer life expectancy than commonly used incandescent or halogen incandescent sources that are used in PAR lamps. However, HID light sources require special ballasts that are larger and heavier than the transformers used for conventional lamps. In addition, larger HID sources typically start more slowly than incandescent/halogen sources, and many cannot be cycled on and off rapidly. To provide adequate start times, multiple smaller HID sources are often used in place of a single large HID source. HID light sources are also susceptible to mechanical vibration and shock damage, burn position misalignment, excessive numbers of start cycles, and the like. 
         [0007]    Accordingly, it is desirable to provide an exterior illumination system for airplanes that decreases the number of light sources used and, hence, decreases the overall weight of the aircraft. In addition, it is desirable to provide a lighting system architecture for airplanes that does not expose light assemblies to damage from debris and vibration. It also is desirable to provide a lighting system architecture that can take advantage of new light technologies. Furthermore, other desirable features and characteristics of the below-described lighting architectures will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background. 
       BRIEF SUMMARY 
       [0008]    In accordance with an exemplary embodiment, an illumination system for illuminating a plurality of positions exterior to an aircraft comprises a first light assembly coupled to the aircraft. The first light assembly comprises a first light source. The first light assembly is configured to produce a first light beam from the first light source and direct the first light beam at a first position during a first operational mode and at a second position during a second operational mode. A second light assembly also is coupled to the aircraft and comprises a second light source. The second light assembly is configured to produce a second light beam from the second light source and direct the second light beam at a third position during the first operational mode and at a fourth position during the second operational mode. 
         [0009]    In accordance with another exemplary embodiment, an airplane includes a body and a first light assembly coupled to the body. The first light assembly is configured to produce a first light beam and direct the first light beam at a first position when the airplane is directed along a first path, at a second position when the airplane is directed along a second path, and at the second position when the airplane is directed along a third path. A second light assembly is coupled to the body and is configured to produce a second light beam and direct the second light beam at a third position when the airplane is directed along the first path, at the third position when the airplane is directed along the second path, and at a fourth position when the airplane is directed along the third path. 
         [0010]    In accordance with a further exemplary embodiment, an illumination system for illuminating a plurality of positions exterior to an aircraft is provided. The illumination system has a first light assembly that comprises a light source for producing a light beam, a first directing means for directing the light beam to a first position during a first operational mode of the aircraft, and a second directing means for directing the light beam to a second position during a second operational mode of the aircraft. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    Various embodiments will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein: 
           [0012]      FIG. 1  is a top view of an airplane with a conventional lighting architecture; 
           [0013]      FIG. 2  is a side view of an airplane with a conventional lighting architecture; 
           [0014]      FIG. 3  is a top view of an airplane with a lighting architecture that utilizes multi-functional light assemblies, in accordance with an exemplary embodiment; 
           [0015]      FIG. 4  is a schematic view of a multi-functional light assembly of  FIG. 3 ; 
           [0016]      FIG. 5  is a side view of a light source movable by a chain or belt coupled to a motor in accordance with an exemplary embodiment; 
           [0017]      FIG. 6  is a side view of a light source movable along a shaft via a jack screw arrangement in accordance with an exemplary embodiment; 
           [0018]      FIGS. 7 and 8  are side views of a light source with a movable lens or reflector assembly in accordance with an exemplary embodiment; 
           [0019]      FIGS. 9 and 10  are side views of a light source with a movable lens or reflector assembly in accordance with an exemplary embodiment; 
           [0020]      FIG. 11  is a side view of a light source with a variable configuration reflector in accordance with an exemplary embodiment; 
           [0021]      FIG. 12  is a side view of a light source with a variable configuration lens in accordance with an exemplary embodiment; 
           [0022]      FIG. 13  is a side view of an airplane utilizing multi-function light assemblies that are coupled to the wing of the airplane and that are configured to function as landing light assemblies in accordance with an exemplary embodiment; 
           [0023]      FIG. 14  is a side view of the airplane of  FIG. 13  with the multi-function light assemblies configured to function as taxi lights in accordance with an exemplary embodiment; 
           [0024]      FIG. 15  is a side view of an airplane utilizing multi-function light assemblies that are coupled to the nose gear of the airplane and that are configured to function as landing light assemblies in accordance with an exemplary embodiment; 
           [0025]      FIG. 16  is a side view of the airplane of  FIG. 15  with the multi-function light assemblies configured to function as taxi light assemblies; 
           [0026]      FIG. 17  is a top view of an airplane utilizing multi-function light assemblies that are coupled to the nose gear of the airplane and that are configured to function as runway turnoff light assemblies in accordance with an exemplary embodiment; 
           [0027]      FIG. 18  is a top view of the airplane of  FIG. 17  with the multi-function light assemblies configured to function as landing light assemblies in accordance with an exemplary embodiment; 
           [0028]      FIG. 19  is a top view of an airplane utilizing a set of multi-function light assemblies and a set of second light assemblies, with the multi-function light assemblies configured as runway turnoff light assemblies and with the second light assemblies configured as landing light assemblies in accordance with an exemplary embodiment; 
           [0029]      FIG. 20  is a top view of the airplane of  FIG. 19  with the multi-function light assemblies configured to augment the landing lights of the second light assemblies in accordance with an exemplary embodiment; 
           [0030]      FIG. 21  is a top view of an airplane utilizing two sets of light assemblies, one set of which comprises multi-function light assemblies, with the multi-function light assemblies configured as runway turnoff light assemblies or as landing light assemblies in accordance with an exemplary embodiment; 
           [0031]      FIG. 22  is a top view of the light patterns of the second set of light assemblies of  FIG. 21  in accordance with an exemplary embodiment; 
           [0032]      FIG. 23  is a side view of the light patterns of the second set of light assemblies of  FIG. 22 ; 
           [0033]      FIGS. 24-26  are top views of an airplane with steerable light assemblies in accordance with an exemplary embodiment; and 
           [0034]      FIG. 27  is a top view of an airplane with multi-function light assemblies that are mounted in the fuselage of the airplane and that are configured to function as runway turnoff light assemblies and as wing illumination light assemblies in accordance with an exemplary embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0035]    The following detailed description is merely exemplary in nature and is not intended to limit the described embodiments or the application and uses of the described embodiments. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description. In addition, while the figures used herein may indicate a particular model or manufacturer of an airplane, it is understood that the various embodiments are not limited to a particular model or manufacturer and can be used for any suitable aircraft. 
         [0036]    The various embodiments of the novel airplane lighting system architecture described herein utilize multi-function light assemblies to perform various functions depending on the operational mode of the airplane. This architecture is a more efficient design strategy than conventional architectures utilizing single-function light assemblies. The various embodiments of the novel architecture can utilize light assemblies that are mounted into relatively protected areas of the airplane, where vibration, debris and wind are less likely to damage the assemblies. Because the light assemblies perform more than one function, fewer light assemblies are required on an airplane. Thus, space requirements and weight of the airplane are reduced. 
         [0037]    Referring to  FIG. 3 , in an exemplary embodiment, a first multi-function light assembly  152  is mounted on a wing root  156  of a first wing  158  of an airplane body  150  and a second multi-function light assembly  154  is mounted on a wing root  160  of a second wing  162 . As described in more detail below, light assemblies  152  and  154  comprise at least one light source (not shown). Light beams  164  and  166  from light assemblies  152  and  154 , respectively, can be directed at a first position with a first beam intensity pattern or at a second position with the first beam intensity pattern or a second beam intensity pattern depending on a selected operational mode of the airplane and thus the light assemblies  152  and  154  can perform different functions during different operational modes. For example, as illustrated in  FIG. 3 , during landing or takeoff, light assemblies  152  and  154  can function as landing light assemblies. Conventional landing lights typically produce narrower more intense light beams than conventional runway turnoff lights. In this regard, light assemblies  152  and  154  each would produce a narrow intense light beam  164  and  166  that is directed at a first position  168  and  170  toward the front of the plane, respectively. During taxing, light assemblies  152  and  154  can function as taxi lights or runway turnoff light assemblies. In this regard, light beams  164  and  166  of light assemblies  152  and  154  can be directed at a second position  176 ,  178  toward the front sides of the plane with a wider less intense intensity pattern. 
         [0038]    The light assemblies  152  and  154 , or light sources (not shown) of light assemblies  152  and  154 , can move along a horizontal plane between the first or second position or, alternatively, can move horizontally and vertically. Switching of the positions of the light beams of the light assemblies may be performed by any suitable control mechanism accessible to pilots operating the airplane. In one exemplary embodiment, the pilots may be able to direct the light beams from the light assemblies using one or more joy stick-type devices or knobs. In another exemplary embodiment, the pilots may be able to direct the light beams from the light assemblies by flipping one or more levers or turning one or more switches that change the light beams from a landing light position to a taxiing or runway turnoff light position. In a further exemplary embodiment, a combination of one or more of these devices could be used. A default mode may also be selected for cases where two configurations are selected simultaneously. Other control means, such as on-screen computer control, touch screens, head-positioning monitoring, and the like also may be used to change the position of the light beams. 
         [0039]    As described above, and as illustrated in  FIG. 4 , light assemblies  152  and  154  are mounted in the wing-roots  156  and  160  of wings  158  and  162 , respectively. The light assemblies  152  and  154  can be mounted where landing lights conventionally are mounted at the wing-roots, where runway turnoff lights conventionally are mounted at the wing-roots, or at any other suitable position on the wing-root. Light assemblies  152  and  154  comprise at least one light source  180 , such as a PAR lamp, an HID light source, or the like, mounted in the wing roots. In an exemplary embodiment, light assemblies  152  and  154  are mounted behind a window, lens or other transparent surface  182  disposed in the wing-root that protects the light source(s) from wind and debris. The light intensity pattern generated by the light source(s)  180  can be managed using changeable optics so that a desired wider, less intense pattern is produced while the light assemblies are serving as runway turnoff lights and a narrow, more intense pattern is produced while the light assemblies are serving as landing lights. The changeable optics may include adjustable lenses, adjustable reflectors, and the like. 
         [0040]    The light beams  164 ,  166  from light assemblies  152  and  154  can be directed to a first position, a second position, a third position, etc. by an electronic or mechanical directing means  400 . In one embodiment, the light beams can be directed by moving or rotating light source(s)  180  from one orientation to another using electronic or mechanical moving means. For example, as illustrated in  FIG. 5 , light source  180  can be moved by a moving means  402  comprising a shaft  50  connected to an electric motor  54  via a chain or belt  52 . In other embodiments, light source  180  can be transitioned back and forth along a shaft  56  via a jack screw arrangement  58  or a hydraulic arrangement, as illustrated in  FIG. 6 , can be moved by artificial muscle actuator devices, and the like. The light assemblies  152  and  154  also may comprise limit stops that prevent overshoot and hard stops that may damage the light sources. The light assemblies also may comprise a spring or other energy storage method that would return the light source to a default position upon loss of control of the switching components, or as means to reduce power demands or actuation times. In another embodiment, the light assemblies may monitor aircraft onboard sensors that determine if the airplane is on the ground or in the air and position the light source(s)  180  accordingly. 
         [0041]    Referring to  FIGS. 7 and 8 , in another exemplary embodiment, the light sources  180  of light assemblies  152  and  154  are not movable and the directing means  400  is a reflector assembly  186  comprising one or more reflectors that is moved into or out of the light beam created by light source(s)  180  to direct the light beam(s) created by the light source(s) from a runway turnoff pattern to a landing/takeoff pattern, or from a landing/takeoff pattern to a runway turnoff pattern. A reflector assembly  186  can be moved into or out of the path of the light beam created by each light source  180  of the light assemblies or a reflector assembly  186  can be moved into or out of the path of light beams created by two or more light sources  180 . The reflector assembly  186  can be moved or rotated from one orientation to another by electronic or mechanical means. For example, similar to the above-described means for moving light sources, reflector assembly  186  can be moved about a shaft connected via a chain or belt to an electric motor, can be transitioned back and forth along a shaft via a jack screw arrangement or a hydraulic arrangement, can be moved by artificial muscle actuator devices, and the like. The light assemblies  152  and  154  also may comprise limit stops that prevent overshoot and hard stops that may damage the reflector assemblies. The light assemblies also may comprise a spring or other energy storage method that would return the reflector assemblies to a default position upon loss of control of the switching components, or as means to reduce power demands or actuation times. In another embodiment, the light assemblies may monitor aircraft onboard sensors that determine if the airplane is on the ground or in the air and position the reflector assemblies accordingly. In another exemplary embodiment, the directing means  400  comprises a reflector assembly  186  and a moving means, such as moving means  402  of  FIG. 5  or  6 . In this regard, reflector assemblies  186  and the moving mechanisms that move the light sources  180  can be used to direct the light beams from a runway turnoff pattern to a landing/takeoff pattern, and vice versa. Alternatively, or in addition, reflector assemblies  186  can be used to refract the light of the light sources  180 , thus increasing or decreasing the width of the light beam. Accordingly, reflector assemblies  186  can be used to widen or narrow the light beam as is suitable during taxing or landing/takeoff, respectively. In another exemplary embodiment, as illustrated in  FIG. 11 , reflector assemblies  186  can comprise variable configuration reflectors  190  that can be actuated to change from a first configuration or shape  192  to a second configuration or shape  194 . For example, the variable reflector can be fabricated from a flexible material that can be manipulated by an actuator to change shape. 
         [0042]    Referring to  FIGS. 9 and 10 , in another exemplary embodiment, the light source(s) of light assemblies  152  and  154  are not movable and the directing means  400  is a lens assembly  188  comprising one or more lenses that is moved into or out of the light beam created by light source(s)  180  to direct the light beams(s) created by the light sources(s) from a runway turnoff pattern to a landing/takeoff pattern or from a landing/takeoff pattern to a runway turnoff pattern. A lens assembly  188  can be moved into or out of the path of the light beam created by each light source  180  of the light assemblies or a lens assembly  188  can be moved into or out of the path of light beams created by two or more light sources  180 . The lens assembly  188  can be moved or rotated from one orientation to another by electronic or mechanical means. For example, lens assembly  188  can be moved about a shaft connected via a chain or belt to an electric motor, can be transitioned back and forth along a shaft via a jack screw arrangement or a hydraulic arrangement, can be moved by artificial muscle actuator devices, and the like. The light assemblies  152  and  154  also may comprise limit stops that prevent overshoot and hard stops that may damage the lens assemblies. The light assemblies also may comprise a spring or other energy storage method that would return the lens assemblies to a default position upon loss of control of the switching components, or as means to reduce power demands or actuation times. In another embodiment, the light assemblies may monitor aircraft onboard sensors that determine if the airplane is on the ground or in the air and position the lens assemblies accordingly. In a further exemplary embodiment, the directing means  400  comprises a lens assembly  188  and a moving means, such as moving means  402  of  FIG. 5  or  6 . In this regard, lens assemblies  188  and the moving mechanisms that move the light source(s)  180  can be used to direct the light beams from a runway turnoff pattern to a landing/takeoff pattern, and vice versa. Alternatively, or in addition, lens assemblies  188  can be used to refract the light of the light source(s)  180 , thus increasing or decreasing the width of the light beam as is suitable during taxing or landing/takeoff, respectively. In another exemplary embodiment, as illustrated in  FIG. 12 , lens assemblies  188  can comprise variable configuration lenses  196  that can be actuated to change from a first configuration or shape  198  to a second configuration or shape  200 . For example, the variable configuration lens can be fabricated from a flexible material that can be manipulated by an actuator to change shape. In another embodiment, light assemblies  152  and  154  can use any combination of the lens assemblies  188 , reflector assemblies  186 , and moving means to direct the light beams from light source(s)  180 . It will be appreciated that other devices and methods can be used to change the direction of the light beams from light sources  180  and the width of the light beams. 
         [0043]    While the light assemblies  152  and  154  are described above for dual use as landing/takeoff lighting systems and as runway turnoff lighting systems, it will be appreciated that use of light assemblies  152  and  154  are not limited to these functions. For example, the light beams  164  and  166  produced by light assemblies  152  and  154  can be directed to a first position  70  so that light assemblies  152  and  154  can be used as landing light assemblies during landings/takeoffs, as illustrated in  FIG. 13 , and to a second position  72  so that light assemblies  152  and  154  can be used as taxi light assemblies during taxiing of the airplane, as illustrated in  FIG. 14 . Alternatively, light assemblies  152  and  154  can be used as landing lights during landing/takeoffs, as taxi lights during taxiing, and as runway turnoff lights during taxing. 
         [0044]    Referring to  FIGS. 15 and 16 , in another embodiment, at least one of the light assemblies  152  and  154  (hereinafter light assembly  152 ) is mounted on nose gear  220  of the airplane body  150 . In this regard, the light beam  164  produced by light assembly  152  can be directed to a first position  74  so that the light assembly can function as landing light assembly during landings/takeoffs, as illustrated in  FIG. 15 , and to a second position  76  so that the light assembly can function as taxi light assembly during taxiing, as illustrated in  FIG. 16 . In another exemplary embodiment, the light beam  164  produced by light assembly  152  can be directed to a first position  78  so that light assembly  152  can function as a runway turnoff light assembly during taxiing, as illustrated in  FIG. 17 , and to a second position so that light assembly  152  can function as a landing light assembly during landings/takeoffs, as illustrated in  FIG. 18 . In a further embodiment, the light beam  164  produced by light assembly  152  can be directed so that light assembly  152  can function as a runway turnoff light and as a taxiing light. In yet another embodiment, the light beam  164  produced by light assembly  152  can be directed so that light assembly  152  can function as a runway turnoff light and/or as a taxiing light during taxiing and as a landing light during landing/takeoff. Alternatively, or in addition, at least one light assembly  152  can be coupled to or proximate to the nose region or tail region of the airplane body. 
         [0045]    As described above, the light beams  164  and  166  of light assemblies  152  and  154  can be directed by using a moving mechanism that moves the light source(s)  180  of the light assemblies, by reflector assemblies and/or lens assemblies that are moved into the light beams to change their patterns, and/or by variable configuration reflectors and/or lenses. In addition, reflector and/or lens assemblies can be used to refract the light of the light source(s) of the light assemblies to widen or narrow the width of the light beams. In another embodiment, light assemblies  152  and  154  can use any combination of the above to direct the light beams from light source(s)  180 . 
         [0046]    Light assemblies  152  and  154  can also be used to augment the light from another light assembly or light assemblies. For example, referring to  FIGS. 19 and 20 , each of light assemblies  152  and  154  can be mounted on the wing-root of the wings  158  and  162  of the airplane body  150  proximate to a second light assembly  230  and  232 , respectively. Light beams  164  and  166  from light assemblies  152  and  154  can be directed to a first position so that light assemblies  152  and  154  function as runway turnoff lights while second light assemblies  230  and  232  produce light beams  238  and  240 , respectively, to function as landing lights, as illustrated in  FIG. 19 . Referring to  FIG. 20 , the light beams  164  and  166  also can be directed to a second position  84  so that light assemblies  152  and  154  augment light beams  238  and  240  from second light assemblies  230  and  232 , thus increasing the light used for landings/takeoffs. It will be appreciated that light assemblies  152  and  154  can be mounted and used for any other suitable function during one operational mode and to augment light beams of another light assembly during another operational mode. For example, at least one of the light assemblies  152  and  154  can be mounted on the nose or nose gear and can be used as a taxi light during taxiing and can be used to augment the light beams from landing lights during takeoffs/landings. Similarly, light assemblies  152  and  154  can be mounted on the wing roots and can be used as landing lights during takeoffs/landings and can be used to augment the light from runway turnoff lights or from taxi lights. 
         [0047]    In another exemplary embodiment, lighting during the operational functions of landing/takeoff, runway turnoff, and taxiing can be performed by two sets of light assemblies. For example, as illustrated in  FIG. 21 , a first set of multi-function light assemblies  152  and  154  are mounted at the wing-roots of wings  158  and  162 , respectively, close inboard to fuselage  250  of airplane body  150 . During landing and takeoff, the light beams  164  and  166  produced by light assemblies  152  and  154 , respectively, are directed to a first position  304  so that light assemblies  152  and  154  function as landing light assemblies. Light beams  164  and  166  also can be directed to a second position  306  so that light assemblies  152  and  154  function as runway turnoff light assemblies during taxiing. A second set of light assemblies  352  and  354  are mounted at the wing-roots of wings  158  and  162  outboard of light assemblies  152  and  154 , respectively. Referring to  FIGS. 22 and 23 , in an exemplary embodiment, light assemblies  352  and  354  are configured so that their lighting patterns are canted slightly downward and turned slightly inboard. During landing, light beams  308  and  310  produced by light assemblies  352  and  354 , respectively, illuminate the runway surface during landing. The canting of light beams  308  and  310  also would illuminate the area under the fuselage  250  that would typically be illuminated by conventional retractable and/or nose gear-mounted light assemblies. In another exemplary embodiment, light assemblies  352  and  354  also could be multi-function light assemblies that produce light beams that are directed from a first position, such as for landing, to a second position, such as taxiing. 
         [0048]    Referring to  FIGS. 24-26 , in another exemplary embodiment, light assemblies  352  and  354  are steerable, that is, the light beams produced from light assemblies  352  and  354  can be steered continuously from one position to another. In one embodiment, the light assemblies are coupled to a direction input mechanism  360 , such as a lever, a joy stick, a steering wheel, or the line. In another embodiment, the direction input mechanism is the nose wheel  360  of nose gear  220 . When the nose wheel is pointed substantially to the front of the airplane body  150 , as illustrated in  FIG. 24 , light beams  362  and  364  produced by light assemblies  352  and  354  both point to the front of the aircraft at a first position  366 . When the nose wheel  360  is rotated to the right, as illustrated in  FIG. 25 , light beam  364  from light assembly  354  is directed to a second position  368  corresponding to the direction that the nose wheel  360  is pointing. Light beam  362  produced from light assembly  352  remains at position  366  to illuminate the area to the front of the airplane. When the nose wheel  360  is rotated to the left, as illustrated in  FIG. 26 , light beam  362  from light assembly  352  is directed to a second position  370  corresponding to the direction that the nose wheel  360  is pointing. Light beam  364  produced from light assembly  354  would remain at position  366  to illuminate the area to the front of the airplane. 
         [0049]    Referring to  FIG. 27 , in another exemplary embodiment, light assemblies  152  and  154  may be mounted within fuselage  250  of airplane body  150 . Light beams  164  and  166  produced by light assemblies  152  and  154 , respectively, can be directed to a first position  256  so that light assemblies  152  and  154  function as wing illumination light assemblies, such as during an ice inspection. Light beams  164  and  166  also can be directed to a second position  258  so that light assemblies  152  and  154  function as runway turnoff light assemblies during taxiing. As described above, the light beams of light assemblies  152  and  154  can be directed by using moving mechanisms that move or turn the light sources of the light assemblies, by reflector assemblies and/or lens assemblies that are moved into the light beams to change their patterns, and/or by variable configuration reflectors and/or lenses. In addition, reflector and/or lens assemblies can be used to refract the light of the light source(s) of the light assemblies to widen or narrow the width of the light beams. In addition, any combination of the above can be used to change the direction of light beams  164  and  166 . 
         [0050]    Accordingly, various embodiments of a novel airplane lighting system architecture have been described. The various embodiments utilize multi-function light assemblies to perform various functions depending on the operational mode of the airplane. While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the described embodiments in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the exemplary embodiment or exemplary embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope as set forth in the appended claims and the legal equivalents thereof.