THIS INVENTION relates to a platform for supporting an aircraft on the ground. The invention is particularly applicable to situations where it is necessary for a aircraft to be parked in an exposed environment.

A major problem associated with parking aircraft and particularly light aircraft is their susceptibility to wind conditions. Due to the light-weight aerodynamic construction of aircraft, it is generally imperative that evasive action be taken to minimize the effect of the wind thereon whenever the aircraft is to be stationed on the ground for any length of time. The most common way to alleviate this effect, is to ensure that the nose of the aircraft is pointed into the general direction of the prevailing winds. In such case, the aircraft presents a minimum surface area to the wind-front, thereby allowing the wind to be deflected with minimal resistance in the longitudinal direction of the aircraft. In the worst case, the side of the aircraft faces the wind direction and hence presents the maximum surface area of the air¬ craft to the wind-front. In the latter case the wind is deflected with maximum resistance past the aircraft, thereby enabling a significant force to be exerted upon the side of the aircraft. Furthermore, because of the aerodynamically imposed design of fixed wing aircraft, the side thereof is least able to absorb the effect of this side force, and hence upon the wind speed attaining a critical velocity, the aircraft may overturn or be subject to structural damage.

In regions where the wind direction is fairly constant or predictable, there is no real difficulty in pointing the nose of the aircraft into the direction of the wind when parking. However, in regions which experience gusty wind

conditions of varying direction or where storm conditions may arise, the aircraft must undergo constant surveillance to ensure that the side thereof is never facing windward.

It is an object of the present invention to provide an aircraft supporting platform which maintains the nose of an aircraft supported thereby in a windward direction.

In one form the invention resides in an aircraft support¬ ing platform comprising a base adapted to be fixed rela¬ tive to the ground, and an aircraft support means capable of rotation in a plane generally parallel to the ground, wherein said support means is adapted to rotate relative to said base in response to the application of a lateral force to an aircraft supported thereon.

Preferably the support means includes a receiving means to receive and support the undercarriage of an aircraft, said receiving means having an undercarriage locating compart¬ ment and entry means, whereby said entry means forms a ramp to facilitate access or exit of the aircraft under¬ carriage to or from said compartment.

The receiving means is preferably pivotally mounted to said support means about an axis generally parallel to the ground whereby said entry means contacts the ground to form said ramp upon pivoting the receiving means to a first position and the entry means clears the ground upon pivoting to a second position.

Preferably the disposition of the receiving means is determined by the location of said undercarriage relative to said compartment.

The receiving means are preferably variably adjustable relative to the support means to precisely coincide with

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the relative disposition of the undercarriage of an air¬ craft.

Preferably, the base includes a circular track upon which the support means is adapted to traverse upon rotation thereof, whereby said track affords additional strength to the support means to facilitate supporting relatively heavy aircraft.

The invention will be better understood in the light of the following description of several embodiments thereof which is made with reference to the accompanying drawings wherein:-

Pig. 1 is a plan elevation of the supporting platform for light aircraft as described in the first embodi¬ ment;

Pig. 2 is a part sectional side elevation of Fig. 1; Fig. 3 is a side elevation of the wheel receiving member;

Pig. 4 is a plan elevation of the supporting platform for light aircraft as described in the second embodi¬ ment;

Pig. 5 is a plan elevation of the supporting platform for larger aircraft as described in the third embodi¬ ment; and Fig. 6 is a part sectional side elevation of Fig. 5.

The first embodiment is directed towards a supporting platform for light, fixed-wing aircraft which have an undercarriage comprising a pair of side wheels and a nose wheel.

The supporting platform 11 consists generally of a base 12 and an aircraft support means 13. The base has a main shaft support 14 fixed vertically within a concrete foot-

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ing 15 located permanently within the ground 16, so that the upper peripheral edge of the support is approximately aligned with the ground surface. The shaft support 14 has a series of radially projecting ribs 14a mounted thereon to maintain the support in fixed position within the footing. A shaft 17 is mounted within the shaft support 14 for journaled rotation relative thereto and is provided with a circumferential flange 21 near its upper end 17a. The underside of the flange 17a abuts against the upper peripheral edge of the shaft support 14 to maintain the upper shaft end 17b a fixed distance from the ground surface.

The aircraft support means generally comprises a pair of longitudinal beams 18 and a pair of transverse beams 22. The longitudinal beams extend in opposite horizontal directions from the upper shaft end 17b, substantially normal to the longitudinal axis of the shaft 17 and con¬ sist of coincident front and rear longitudinal beams 18a, 18b respectively. The front beam 18a supports a nose wheel receiving member 19 at the distant end thereof, and the rear beam 18b supports a hook 20 at the distant end thereof. The transverse beams consist of front and rear beams 22a, 22b and are attached transversely and respec¬ tively to the front and rear longitudinal beams 18 near the shaft end 17b. The transverse beams 22 are essen¬ tially parallel to each other and coplanar with the longi¬ tudinal beams 18. The opposing ends 24a, 24b of the transverse beam pair 22, each support a side wheel receiv¬ ing member 25, each member being equidistantly positioned from the shaft 17.

The wheel receiving members 19 and 25 combine to form a receiving means to receive and support the undercarriage of an aircraft and are precisely located on their respec¬ tive supporting beams to accord with the corresponding

displacement of the wheels on the undercarriage of an aircraft which is to be supported by the platform.

Each wheel receiving member essentially comprises an undercarriage locating compartment, defined by a floor 26 and peripheral walls 27, and an entry means, defined by an extension of the floor from the compartment. The floor 26 is preferably rectangular in plan such that a rear wall 27a extends from the rear peripheral edge of the floor and side walls 27b, 27c extend from part of the side periphe¬ ral edges of the floor.

The wheel receiving member is attached to the leading edge of a supporting beam by means of a hinge 28 located at an intermediate position of the floor 26 thereof. The pivo¬ tal axis of the hinge 28 is substantially normal to the direction of the longitudinal beams 18 and lies in a plane generally parallel to the ground.

In the case of the nose wheel receiving member 19, the compartment is hinged to the distant end of the front longitudinal beam 18a, such that the rear end 29 of the floor 26 is supported by the surface of the beam 18a in a generally horizontal plane.

In the case of the side wheel receiving members 25, the compartments are respectively hinged to the front longi¬ tudinal edge of the front transverse beam 22a at opposing ends thereof, such that the rear end 29 of the floor 26 is supported by the rear transverse beam in a generally horizontal piane.

The front portion 30 of the floor 26 cantilevers a finite distance from the hinge and leading beam edge towards the front of the platform so defining the entry to the wheel receiving member. In addition, each compartment is provi-

ded with a locking means having a bar 33, which can be fixed along opposing top edges 34 of the side walls 27. The bar is arranged such that one end thereof is pivotally connected to one side wall edge and the other end may be brought into locking engagement with the other side wall edge, whereby the compartment may be effectively closed at the front thereof. Thus upon the application of a down¬ ward force to the front portion 30 of the compartment floor, the compartment will pivot, as shown by the dotted lines in Fig. 3, about the hinge 28, until the front peripheral edge of the floor 26 engages with the ground 16, thereby providing a ramp to facilitate the access or exit of a wheel to or from the compartment.

Outwardly extending tie bars 31 are connected to opposite ends of the rear transverse beam 22b, each tie bar having a hook 32 fixed to the outer end thereof.

Now describing the operation of the supporting platform, an aircraft is positioned to the front of the platform with the nose of the aircraft pointing in a similar direc¬ tion to that of the front longitudinal beam 17. The wheel receiving members 19 and 25 of the platform are aligned exactly with the corresponding wheels of the aircraft, by rotating the platform about its shaft support 14. Upon correct alignment, the aircraft may be winched or pushed rearwardly, so that each of its wheels engage the front edge of the floor 26 of each corresponding compartment, whereby a downward force will be applied to the front floor portion 30. Thus each compartment will tilt for- wardly defining a ramp to provide access for the wheels thereto. As a wheel rides up the ramp past the position of the hinge 28, the torque about the hinge will reverse and hence the compartment will return to its original position with the floor 26 thereof disposed in a horizon¬ tal plane. Each wheel can proceed along the rear position

29 of the compartment floor 26 until abutment is made with the rear wall 27a. In this position the locking bar 33 may be brought into locking engagement with the side wall of the compartment, thus blocking the front entry to the compartment and securing the wheel therein.

Without the aircraft located on the support means, the tail may be tied to the hook 20 of the rear longitudinal beam, and the wings tied to the hooks 32 of the tie bars 31.

In this arrangement, the aircraft by the action of its aerodynamic shape, will cause the platform to rotate about the shaft support until the nose of the aircraft points windward. Any sudden change of wind direction can be easily accommodated as any lateral force applied to the aircraft will cause the platform to change its attitude so that a minimum torque is applied thereto. As the minimum torque is achieved when the nose of the aircraft is point¬ ing windward, the platform will naturally compensate for any change in wind direction.

The second embodiment is directed towards a supporting platform for light, fixed-wing aircraft having an under¬ carriage comprising a pair of side wheels and a tail wheel.

This embodiment is shown in Fig. 4, and is essentially the same as the previous embodiment, except that the front longitudinal beam is no longer required. In addition, to facilitate placement of the aircraft upon the platform 35, the side wheel receiving members 36 are reversed such that the compartment is hinged to the trailing longitudinal edge of the rear transverse beam 37, with the rear portion of the floor 38 projecting in cantilevered fashion there¬ from to form the entry means. The front edge of the floor

38 is provided with a front wall 39 and tie bars 40 extend outwardly from opposite ends of the front transverse beam 41. Furthermore, the rear longitudinal beam 42 is provi¬ ded with a tail wheel receiving member 43 at the distant end thereof. The tail wheel receiving member 43 is con¬ figured similarly to the side wheel receiving members 36, whereby access is provided to the compartment thereof from the rear.

In operation, the aircraft intended to be supported, is positioned to the rear of the platform facing a similar direction to that of the platform. Consequently, the aircraft is winched or pushed onto the rear portions of the compartment floors 38, and onto the ramps defined thereby. Upon the wheels of the aircraft engaging the front walls 39 of the compartments, locking bars (not shown) may be locked into position blocking the rear entry to the compartment. The aircraft may then be tied down as described previously.

The third embodiment again is essentially the same as the first embodiment being in preference directed towards heavier winged aircraft having an undercarriage comprising two side wheels and a nose wheel.

In this embodiment, shown in Figs. 5 and 6, the supporting platform includes a circular track 44 upon which a series of roller wheels 45 may run. The roller wheels are fixed beneath each of the longitudinal beams 46, 47 and the side wheel receiving members 48, each roller being positioned an equal distance from the shaft 49 to provide additional support to the platform whilst preserving the rotational effect thereof.

It should be appreciated that the scope of the present invention is not limited to the scope of the specific

description of the embodiments described herein. Moreover the particular configuration of the platform may be varied to accommodate varying types of aircraft undercarriage whereby the receiving means are variably adjustable rela¬ tive to the support means to precisely coincide ^' with the relative disposition of the undercarriage. Furthermore, improved bearing means may be incorporated to facilitate rotation of said platform. Alternatively, a different platform base may be adopted which eliminates the use of a shaft by using a rail and carriage mechanism.