GB2445744A

GB2445744A - Air-cushion landing system for a hybrid air vehicle which is mounted on the underside of the payload module or passenger cabin

Info

Publication number: GB2445744A
Application number: GB0700793A
Authority: GB
Inventors: Hugh Michael Bonnin Stewart
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-01-16
Filing date: 2007-01-16
Publication date: 2008-07-23
Anticipated expiration: 2027-01-16
Also published as: GB0700793D0; GB2445744B

Abstract

Air-cushion landing gear 3 is mounted on the underside of the payload module 2 so as to create a positive or negative air-pressure chamber 5. Additional smaller air-cushion units 4 may be located within the main chamber 5 so as to assist in take-off and landing and provide redundancy. Lift forces may be generated by both lighter-than-air gases within the hull 1 and the aerodynamic form of said hull. More than one payload or passenger module may be present (figure 2), each being provided with an air-cushion landing system. The air-cushion landing system/s may be retractable.

Description

I

Hybrid Air Vehicle having air-cushion landing gear mounted under the payload module / cabin

Description

This invention relates to the integration of an air-cushion landing system with the payload module(s) or passenger cabin(s) of a hybrid air vehicle.

The concept of a hybrid air vehicle, an aircraft design with both aerodynamic and aerostatic lift, is now well established. Hybrid air vehicles may employ a rigid internal structure, typically a framework of metal or composite materials, or they may have no rigid internal structure but retain their shape by maintaining an internal pressure that is always greater than the ambient air pressure at any given altitude -so-called "pressure-stabilised" airships. In either case, only part of the lift is provided by lighter-than-air gases (specifically, helium) and the remaining part of the lift is derived from the aerodynamic form of the hull in the manner of an aeroplane or flying wing -so-called "hybrid air vehicles". This hybrid design offers significant advantages in terms of payload capability and ground handling over conventional airships, which operate lighter-than-air and entail complex and costly procedures to manage on the ground.

One example of a pressure-stabilised hybrid air vehicle is described in WO-A-Ol/94l72 and combines the characteristics of an aeroplane, an airship and a hovercraft. In this design, the hybrid air vehicle has a contoured gas-filled flattened hull including a pair of longitudinally extending lobes defining, on the under-side of the hull, a longitudinally extending central recess in which is received a payload module, with air-cushion landing gear means attached to the underside of the outer lobes of the hull.

In the above-mentioned design, two sets of air-cushion landing systems are mounted on the underside of the hull side lobes; these may be relatively widely spaced apart so as to improve the stability of the air vehicle when on the ground and when landing and taking off. The air-cushion landing gear units are specifically attached to the outer lobes of the hull as required by the airship design and the specific configuration of the payload module it envisages.

Air-cushion landing gear offers certain significant advantages. For instance, there is no need to have perfectly flat runways for the vehicle to land and take off: the vehicle can land on any reasonably flat surface, including water. Moreover, after the vehicle lands and the air supply is turned off, or reversed, it will be gently lowered down, enabling easy loading and unloading of cargo from a ramp of the payload module.

Finally, the air-cushion motors can be reversed to provide suck-down forces, effectively anchoring the vehicle to the ground for general mooring purposes or for compensating when payload or passengers are being off loaded. In flight, the air-cushion systems are preferably retracted to decrease drag.

The above-mentioned and similar designs have certain inherent limitations when applied to the transportation of passengers or other cargo with a relatively high ratio of volume to weight. To overcome these limitations, an invention is described in patent application no. GB 0619730.5 in which is proposed a design of payload module or modules or passenger cabin or cabins that is or are mounted beneath the hull and contiguous with the whole or part of the lower surfaces of the hull envelope including, where relevant, the outer lobes of the hull envelope in a manner designed to maximise the volume and space available in relation to the payload weight.

The present invention defines an elaboration on the general landing systems proposed in the design described in GB 0619730.5 but is not limited to this design. In this invention, the air-cushion landing gear means are attached to the under surface of the payload module or passenger cabin, or payload modules or passenger cabins, rather than to the hull or lobes of the hull itself, thereby offering to this design of vehicle all the advantages in ground handling, manoeuvrabiiitY and mooring offered by air-cushion landing systems in general as described above.

Air-cushion landing gear typically comprise flexible curtain means surrounding an air-cushion cavity and air means for supplying compressed air to the cavity to provide a cushion of air for supporting the vehicle during landing and take-off. Preferably the air-cushion unit or units will include means for rapidly exhausting air from the air-cushion cavity to provide a suck-down force for holding the vehicle in position on the ground for mooring or payload transfer. In the present invention, there may be one or multiple air-cushion units mounted beneath the payload module or modules.

The design allows for certain optional or additional features, such as: (a) the air-cushion landing gear can be attached to some or all of the payload modules or passenger cabins where there may be more than one of these; (b) the number and positioning of the air-cushion landing units can be configured so as to provide optimum efficiency for landing, take-off and mooring; (C) the air-cushion landing units may be used, if appropriate, in conjunction with conventional landing gear, such as retractable or non-retractable high-pressure or low-pressure tyres, or less conventional landing gear such as caterpillar tracks; Cd) the air-cushion landing units may be used, if appropriate, in conjunction with landing gear systems such as described above but to provide a suck-down or anchoring capability only; Ce) the air-cushion landing units may be retractable into cavities or housings within the underside of the payload module or cabin so as to lie flush or relatively flush with the lower surface of this structure; (f) the curtains as above mentioned may be mounted around the perimeter of all or a substantial part of the underside of the payload module or cabin so as to create a large single chamber or cavity if required; (g) the air-cushion units may be differentially sized or powered to assist, for instance, in take-off and landing where the rear.of the payload module or cabin may be the first portion to touch down and the last to lift off the ground.

Two embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings in which: * 4 Figures la, lb and ic show the preferred embodiment applied to a single payload module, from one end, from one side and from underneath.

Figures 2a, 2b and 2c show another embodiment applied to two separate payload modules, from one end, from one side and from underneath.

Referring to Figures la, lb and ic, these drawings describe a hybrid air vehicle with a single payload module having two decks 2 and the main propulsion units 6 mounted at the rear of the hull 1. The payload module 2 is mounted beneath the hull 1 and the air-cushion landing system is mounted beneath the payload module 2 50 that the air-cushion curtains 3, shown by dotted lines, run the length of the perimeter of the payload module and create an internal chamber 5. Figure ic shows a configuration in which additional air-cushion units each with its own curtain or curtains, shown by dotted lines, are located within the main chamber 5. These additional units may help establish cushion pressure when the air vehicle is pitched nose-up during take-off and landing.

Further, such additional units would provide redundancy in case of skirt tearing, fan failure, uneven ground or other similar contingencies.

Referring to Figures 2a, 2b and 2c, these drawings describe a hybrid air vehicle with two payload modules 2 mounted beneath the outer lobes of the hull 1, along with the main propulsion units 6 at the rear. The air-cushion landing system 3 is mounted beneath the payload modules 2 so that the air-cushion curtains 3, shown by dotted lines, run the length of the perimeter of the payload modules 2 and create an internal chamber 5. Such a configuration here, as in Figure 1, could allow for more than one separate air-cushion unit, each creating its own chamber, either located within one or more larger chambers 4 or located separately 7. The advantages of a twin payload module design include the ability to provide multiple separate loading ramps, lower envelope stress due to more evenly distributed loading and the possibility of widening the overall hull to provide increased aerodynamic efficiency.

Claims

Claims 1. An air-cushion landing system mounted on the underside of the

payload module or passenger cabin of a hybrid air vehicle;
2. An air-cushion landing system according to Claim 1 in which the payload module or passenger cabin is provided with a deck adapted to extend around all or part of the outer side of the hull envelope or outer lobes of the hull envelope;
3. An air-cushion landing-system according to Claims 1 and 2 in which the payload module or passenger cabin is adapted to cover all or part of the underside of the hull so as to create a large flat area for the transportation of goods or people;
4. An air-cushion landing-system according to Claim 1 where there may be more than one payload module or passenger cabin;
5. An air-cushion landing-system according to Claims 1, 2, 3 and 4 which may comprise a single or multiple units;
6. An air-cushion landing-system according to any of the preceding Claims that may be employed in conjunction with any conventional or non-conventional landing gear system;
7. An air-cushion landing-system according to any of the preceding Claims that may be used either for landing and take-off or for mooring and anchoring, or for both;
8. An air-cushion landing-system according to any of the preceding Claims that may be retractable or non-retractable or partially retractable;
9. An air-cushion landing-system according to any of the preceding Claims where the air cushion units may be differentially sized or powered;
10. An air-cushion landing-system substantially as hereinbefore described with reference to the accompanying drawings.