GB2151575A - Airdrop platform - Google Patents

Abstract

To allow the airdropping of bulky stores from aircraft, a platform 20 is used to carry the store 21 within the aircraft and to carry the store as it leaves the aircraft. A mechanical system on the platform senses when the platform and store have cleared the aircraft to initiate separation of the store 21 from the platform 20 so that each may descend under its own parachute 25, 24 respectively. Where the store 21 is a boat, for instance a semi-inflatable, the aerodynamically induced motion of the boat is used to assist separation of the boat from the platform. <IMAGE>

Description

SPECIFICATION Airdrop platform The present invention relates to the dropping of stores from aircraft, particularly where a rigid hulled boat is to be dropped, primariiy for a quick reaction sea rescue purposes.

Techniques for the dropping of stores by parachute from aircraft are well known and practised throughout the world. They fall into two categories, dependant on whether the store is to be dropped onto land or water. For land drops, the store, for instance a vehicle, is tied securely to a platform and the platform and vehicle are dropped, usually from the rear loading door of an aircraft. A parachute system is opened under the action of a static line after the platform and store has cleared the aircraft to control the rate of descent of the store. When the platform and store, still attached to one another, have landed the store may be separated from the platform for use.

The store may need to be strengthened to withstand the shock of landing.

When dropping a boat over water, the known practise is to drop the boat from an aircraft bomb bay or loading ramp without a platform attached, parachutes on the boat being deployed by the action of static lines.

This technique imposes limitations on the boat which may be dropped. Firstly, the size of the boat is limited to the dimensions of the bomb bay or to the maximum size which may be secured in flight and then manhandled for dropping. Secondly, the boat is to be dropped into a region of turbulent air adjacent to the fuselage of the aircraft and as a result the boat may turn and strike the aircraft from which it has been dropped.

To drop a larger boat from the loading ramp at the rear of an aircraft will therefore require the boat to be supported in the aircraft on a platform which can be rolled out of the aircraft with the platform assisting the stability of the boat as it leaves the aircraft.

According to the present inventjion there is provided a platform for the support of a droppable store within an aircraft, the store and platform being adapted to be ejected in a substantially rearward direction from the aircraft, having means for initiating the detachment of the store from the platform as the platform leaves the aircraft, the store and platform descending at independently controlled rates.

The means for initiating the separation of store and platform may comprise an arm movable relative to the platform supported by the aircraft floor, said arm moving when support from the aircraft floor is removed to release clamps holding the store to the platform.

The platform may be pulled from the aircraft by the deployment of a partly furled parachute attached to the platform. The initial tension of the line attaching the parachute to the platform releases the clamps locating the platform in the aircraft.

The separation of the store and platform may initiate the opening of the parachutes on the store and the full opening of the parachute on the platform.

The parachutes on the store may alternatively be opened after the separation of the store and the platform by static lines.

When the platform is to carry a boat with a rigid hull a cradle with a flat base is provided on the platform beneath the deepest part of the keel of the boat. On separation of the boat from the platform, rotation of the boat due to aerodynamic effects causes the keel of the boat to strike the flat base, assisting separation of the boat and platform.

The invention will now be described with reference to the accompanying drawings, in which Figure 1 shows schematically in an oblique view an air drop platform suitable for the dropping of a boat from an aircraft.

Figure 2 shows schematically in a side view an air drop platform with attached boat at the moment of ejection from an aircraft.

Figure 3 shows schematically the separation of the boat from the platform and their subsequent descent.

In Fig. 1 the air drop platform 1 indicated by the broad arrow comprises a ladder type base 2 to which are fixed cradles 3 to support the rigid hull of the boat (not shown). Fixed between the centres of the cradles is a flat base 4 to take the impulsive load from the boat (see Fig. 3B). Releasable clamps 5 are used to fix the boat to the platform via cables (not shown). The release of the clamps is actuated by a series of pushrods 8 and quadrants 6.7. The quadrant 7 is held in such a position by the action of the raised drop arm 9, that the action of the linked pushrods and quadrants holds the clamps closed. The drop arm 9 is held in the raised position by the floor of the aircraft (not shown) on which the drop arm slider 10 rests.The platform is arranged to be ejected from the aircraft in which it is travelling in the direction of arrow A, resulting in the drop arm falling from the locking position as shown in the figure to release the clamps only when the end of the platform leaves the aircraft.

In Fig. 2 the platform 20 and boat 21 are shown at the moment of ejection from the loading ramp 22 of aircraft 23. The drop arm 9 has fallen from the locking position shown in Fig. 1 to release the cables 24 from the clamps 5. The ejection parachute 24 remains partly reefed during the ejection from the aircraft. The boat parachute 25 is operated by a static line 26 when the boat is clear of the tail 27 of the aircraft.

In Fig. 3A the boat parachute 25 is partially opened as the boat and platform continue to move with a horizontal component of velocity in the direction of arrow B. The horizontal separation of the boat 21 and the platform 20 is increased by the drag of parachute 24 acting on the platform.

In Fig. 3B separation of the boat 21 and platform 20 has progressed and under the influence of the boat parachute 25 the boat and platform have started to separate vertically. As they do, a rotation of the boat relative to the platform in the direction of arrow C, generated by the motion of the boat through the air in the direction of arrow B causes the forward keel 31 of the boat to strike the flat base 4 of the platform, giving the platform additional downward speed and increasing the rate of vertical separation of boat and platform.

In Fig. 3C the boat 21 is descending under parachute 25 horizontally and vertically separated from the platform 20 descending under parachute 24.

Claims (7)

1. A platform for the support of a store droppable from an aircraft, the store and platform being releasably locked together and adapted to be ejected together in a substantially rearward direction from the aircraft, the platform having means for releasing the store from the platform as the platform leaves the aircraft, the store and platform descending at independently controlled rates.

2. A platform according to claim 1 having releasable locking means for releasing the store from the platform at a predetermined distance after its ejection from the aircraft.

3. A platform according to claim 1 wherein the platform and store assembly are ejected from the aircraft with the assistance of an ejector parachute.

4. A platform according to claim 1 having a store release mechanism mounted on the platform and held in locking engagement by the aircraft floor and arranged such that when the support of the aircraft floor is removed clamping means securing the store to the platform are released so enabling separation of the store and platform.

5. A platform according to any of the preceding claims wherein a cradle is attached to the platform has a cradle adapted to carry a boat with a rigid hull.

6. A platform according to claim 5 wherein the cradle has a flat base at its deepest part, the assembly being arranged such that on separation of the boat from the platform rotation of the boat with respect to the platform causes the keel of the boat to strike the flat base to assist in separation of the boat and platform.

7. A platform for the support of a store droppable from an aircraft substantially as described in the specification and drawings.