Fairing for an expandable bay

A fairing (100) for an expandable bay of an has a ramp (108). A front linkage bar (102) has a first end pivotally connected to a finger (106) of the ramp (108) and a second end pivotally connected to the aircraft. A mating panel (112) is next to an interior edge (132) of the ramp (108) and pivotally connected to the ramp (108). An exterior elastomer panel (124) is connected between an exterior edge (126) of the ramp (108) and the aircraft.

FIELD OF THE INVENTION 
The present invention relates generally to the field of aircraft and more 
particularly to a fairing for an expandable bay. 
BACKGROUND OF THE INVENTION 
Aircraft are generally designed to carry their maximum load in the fuselage 
and/or wings of the aircraft. The fuselage of the aircraft is where any 
loads are stored in flight. In modern military aircraft, it is common for 
the aircraft to have ample thrust to carry larger loads than can fit 
within its fuselage. One way to take advantage of this extra thrust is to 
place these oversized loads externally. These external loads are attached 
to mounts on the wings or fuselage. An example of an aircraft 20 with a 
plurality of oversized loads 22, is shown in FIGS. 1 and 2. Unfortunately, 
these oversized loads 22 result in additional drag that limits the range 
of the aircraft. Expandable bays have been suggested as a solution to 
carry oversized loads. FIG. 3 shows a concept of an aircraft 50 with an 
expandable bay 52. The expandable bay 52 has access doors 54 and a front 
and back fairing 56, 58. One difficulty in producing an effective 
expandable bay 52 is producing a fairing that does not require significant 
space in the fuselage. 
Thus, there exists a need for a fairing for an expandable bay of an 
aircraft that does not require significant space in the fuselage. 
SUMMARY OF THE INVENTION 
A fairing for an expandable bay of an aircraft that overcomes these and 
other problems has a ramp. A front linkage bar has a first end pivotally 
connected to a finger of the ramp and a second end pivotally connected to 
the aircraft. A mating panel is next to an interior edge of the ramp and 
pivotally connected to the ramp. An exterior elastomer panel is connected 
between an exterior edge of the ramp and the aircraft.

DETAILED DESCRIPTION OF THE DRAWINGS 
FIGS. 4 & 5 show an embodiment of the access doors 52 of an expandable bay. 
The access doors 52 have a pair of panels 60 connected to a simple hinge 
62. The simple hinge 62 is connected to a bar 64. The bar 64 is connected 
to a six bar hinge 66. The six bar hinge 66 is connected to the frame 68 
of the aircraft. A plurality of reinforced elastomer panels 70 cover the 
gaps. The reinforced elastomer panels 70 are capable of being stressed up 
to 150% beyond its normal shape and still bounces back to its original 
shape. 
FIG. 6 shows a perspective drawing of an embodiment of the reinforced 
elastomer panels 70. An elastomeric skin 76 has a plurality of flexible 
rods 78 running longitudinally through the elastomeric skin 76. The 
flexible rods are typically made of quartz epoxy. The flexible rods 78 can 
slide within the elastomeric skin 76. The elastomeric skin 76 is attached 
at each end to a pair of rod blocks 80, 81. The flexible rods 78 are 
attached to the rod block 80 and slide within the rod block 81. The rod 
blocks 80, 81 have a plurality of counter sunk screw holes 82 for 
attachment to the aircraft. 
FIGS. 7 & 8 show a cross sectional view of a fairing 100 according to the 
invention. The fairing 100 can be used with the embodiment of the 
expandable bay shown in FIGS. 4 & 5 or with other expandable bays. The 
fairing design is essentially the same for both the front fairing and the 
rear fairing. A front linkage bar 102 is pivotally connected at a first 
end to a mount 104 of the aircraft. A second end of the front linkage 
mechanism 102 is pivotally connected to a linkage stub 106 of a ramp 108. 
A finger 110 of the ramp 108 is pivotally connected to a mating panel 112. 
A chest 114 of the ramp 108 is pivotally connected to a back linkage bar 
116. A second end of the back linkage bar 116 is pivotally connected to a 
mount 118 of the aircraft. A mating panel linkage bar 120 is pivotally 
connected to the back linkage bar 116. A second end of the mating panel 
linkage bar 120 is pivotally connected to the mating panel 112. An 
actuation mechanism (linear actuator) 122 is pivotally connected to the 
mating panel and moves the fairing from a flush position (see FIG. 8) to 
an expanded position (FIG. 7). The actuation mechanism is shown as a 
hydraulic piston, but can be mechanical or electromechanical. An exterior 
elastomer panel 124 is connected between an exterior edge 126 of the ramp 
and the aircraft skin 128. An interior elastomer panel 130 is connected 
between an interior edge 132 of the ramp 108 and an adjacent edge 134 of 
the mating panel 112. The elastomer panels 124, 130 are reinforced 
elastomer panels like the one shown in FIG. 6. 
FIGS. 9 & 10 show a top right perspective drawing of the fairing actuation 
mechanism. The ramp 108 has an exterior surface that is rectangular. The 
ramp 108 has a lip 150 that is used for attaching the reinforced elastomer 
panels. The mating panel 112 has an exterior surface that is triangular. 
The mating panel 112 also has a lip 152 for attaching reinforced elastomer 
panels. 
FIG. 11 is a partial top view of an embodiment of the fairing 100. A side 
elastomer panel 160 is shown connected to the aircraft (skin), the ramp 
and the mating panel 112. Where the side elastomer panel 160 and the front 
elastomer panel 124 meet 162, a plurality of bushing 164 are embedded in 
the elastomer skin. The reinforcing rods from the front elastomer panel 
124 slide freely within the bushings. In another embodiment shown in FIG. 
12, a bar 170 breaks the side elastomer panel 160 into a first elastomer 
panel 172 and a second elastomer panel 174. A six bar hinge 176 connects 
the bar 170 to the aircraft frame. A side linkage bar 178 is pivotally 
connected to the six bar linkage 176 and to the ramp 108. 
Thus there has been described a fairing for an expandable bay of an 
aircraft that does not require significant space in the fuselage. In 
addition, the fairing achieves vertical translation of the mating panel 
112 using only rotation joints. This reduces the weight and maintenance 
compared to sliding joints. While the invention has been described in 
conjunction with specific embodiments thereof, it is evident that many 
alterations, modifications, and variations will be apparent to those 
skilled in the art in light of the foregoing description. Accordingly, it 
is intended to embrace all such alterations, modifications, and variations 
in the appended claims.