EP1370460A1

EP1370460A1 - Circular vertical take-off and landing aircraft

Info

Publication number: EP1370460A1
Application number: EP02703709A
Authority: EP
Inventors: Eric Ronald Walmsley
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-03-07
Filing date: 2002-02-26
Publication date: 2003-12-17
Also published as: WO2002070342A1

Abstract

A circular VTOL aircraft with a central vertically mounted turboprop engine (14), driving contra-rotating co-axial propellers (24), above a central jet engine, or engines (12), horizontally mounted on a turntable (11) and steerable through 360 degrees. The turboprop provides vertical thrust from propellers compressing air from an upper circular intake (5) downward through a circular funnel-shaped rotor-chamber (6), to a circular vent (10) at the base of the aircraft. The resulting column of compressed air gives lift for VTOL operations and a cushion of air in flight. The horizontally mounted turbine provides acceleration, retro-thrust and directional control for horizontal flight and vectored thrust for VTOL. An alternative engine configuration (Figure 9), replaces the turboprop and propellers with a vertical turbojet or rocket-engine system providing direct vertical thrust via four control vents (12/14), with an optional horizontal vectored thrust vent (15/37). he aircraft. Fuel-tanks are installed around the central engines. The flight-deck is at the top-centre of the craft above the engines, which are detachable for maintenance.

Description

CIRCULAR VERTICAL TAKE-OFF & LANDING AIRCRAFT

TECHNICAL FIELD

The invention disclosed relates to the field of VTOL Aircraft with adaptations of the design that can be applied to Airship Technology as well as future Space Operating Vehicle design.

BACKGROUND ART

The background to the invention relates broadly to both helicopter design and VTOL aircraft design (for example the Hawker Harrier) as well as Unmanned Aerial Vehicle (UAV) designs. The invention disclosed shows a new way of thinking about the shape and propulsion of a type of aircraft that is outside the design parameters of conventional aircraft which depend on wings, tail-plane and fuselage, (or in the helicopter an open rotary wing) in order to maintain stable flight. Although the design disclosed uses components of known technology such as contra-rotating propellers, turbo-prop and turbo-jet engines, the way in which they are used to provide both lift, stability and directional control is completely different to conventional systems and shows that the design is novel in concept.

DISCLOSURE OF INVENTION

The invention comprises a circular VTOL aircraft which is capable of vertical and horizontal flight by combining propulsive power from horizontal contra-rotating propellers powered by a central vertically mounted turbo-prop engine giving vertical thrust, with a jet turbine engine, or engines, giving horizontal thrust. The jet engine/s which provide horizontal thrust are mounted on a steerable turntable pod at the centre-base of the aircraft in order to achieve rapid changes in direction through 360 degrees during flight manoeuvres: for example, from forward to reverse flight, from forward to sideways flight through 90 degrees, or from side to side flight through 180 degrees change in direction. The horizontal jet/s may be fitted with vectored thrust nozzles to provide additional thrust on take-off. This design is referred to as VTOL Aircraft 1 in the specification.

The invention allows for the configuration of the design for VTOL Aircraft 1 to be adapted for use in Airship Technology, whereby the large circular passenger compartment may be substituted for gas buoyancy tanks and the horizontal thrust jet is mounted on a gimbal-frame fixed to the turntable so that, as well as turning through 360 degrees, the engine can be angled upwards to provide additional takeoff thrust, or downwards to increase the rate of descent. (This design is shown in Fig 5 of the accompanying drawings).

The invention also allows for an alternative engine system to be employed in the same disc-shaped hull design, whereby the turbo-prop engine driving contra-rotating propellers is replaced by vertically mounted turbo-jet or rocket engines delivering direct thrust downward and outward to four vertical thrust vents situated at cardinal points on plan, below the engine/s, together with power from jet or rocket engines horizontally mounted on a turntable-pod which is steerable through 360 degrees and is situated centrally below the vertical thrust engine or engines. With the jet engines described supplanted by rocket or future plasma engine systems and the main annular body of the craft allocated to fuel storage, the design could be adapted for use as a Space Operating Vehicle. This design is referred to as VTOL Aircraft 2 in the specification. With reference to the design of VTOL Aircraft 1 , the stability of the aircraft is achieved by the gyroscopic effect of the high-speed horizontal rotation of two co-axial propellers, which are geared to contra-rotate at the same speed, thus cancelling the torque and spin effect produced by a single rotor or propeller. The airflow from the propellers is compressed downwards and outwards through a funnel- shaped rotor-chamber to the annular exit vent providing high-pressure thrust that supports the aircraft in the VTOL and hover stages of flight. The horizontal speed of the aircraft described is not limited by aerodynamic problems caused for example by the advancing and retreating blade speeds of the helicopter rotor, because in horizontal flight, with the rotor intake cover closed, the aerodynamic section of the disc-shaped aircraft produces an area of low pressure airflow over the trailing top half of the disc, generating lift in the same way as a conventional aircraft wing in forward flight. With the rotor intake cover closed, the contra-rotating propellers are free to rotate at reduced rpm which is sufficient to provide the gyroscopic stability required for horizontal flight, and at the same time the rotor-chamber becomes partially vacated as air is expelled from the exit vent, allowing the propellers to rotate with reduced air friction, thereby conserving fuel for the turboprop's main purpose of vertical take-off and landing. In the event of engine failure the contra-rotating propellers may be geared to auto-rotate in order to control the rate of descent of the aircraft for an emergency landing.

The horizontal jet thrust may be vectored downwards by vectored thrust nozzles, or by extending a flap from the underside of the craft in order to deflect thrust to cushion the landing: or when the jet engine is gimbal-mounted, thrust can be angled downwards to control the rate of descent. In the event of the horizontal jet turbine engine failing, an emergency landing can be made with the controlled thrust of the turboprop engine and propellers.

The aircraft is designed to fly with the main disc-shaped body maintaining a level horizontal position through all stages of flight, thereby alleviating passenger discomfort experienced during high angle pitch and bank changes experienced in conventional aircraft. However, the aircraft is fitted with control vanes that are used to change or trim the pitch and roll movement of the disc in flight. A combination of thrust from both vertical and horizontal power units will achieve a 45 degree angle of ascent to cruising altitude with the aircraft maintaining a horizontal attitude. Vertical ascent from a helicopter pad or small clearing area can be made using the vertical thrust power alone.

The flight-deck is situated at the top centre of the aircraft and is supported by structural formers above the main central engine(s). As a security feature the passenger compartment is completely separate from the flight-deck and is designed within the main body of the craft, together with cargo, and fuel tanks which are positioned either around the outer or inner circumference of the annular fuselage. The circular plan-shape of the aircraft allows for a very large fuel capacity which will enable this design to out-range the conventional helicopter/VTOL aircraft, as well as to have a relatively higher passenger and cargo carrying ability.

A notable feature of the design is that the passenger compartment, cargo and fuel-tank loadings are all integrated into the main body of the craft that combines the function of both wing and fuselage in one inherently strong disc-shape which generates lift in forward flight, thus avoiding existing problems such as wing-flutter and spar-failure associated with high loading on conventional designs. The circular passenger compartment can be designed either to maximise seating capacity or to include a small service area. (For example, the prototype aircraft is 12 metres in diameter and is designed to carry 24 passengers and 2 flight crew, with fuel capacity of 33 cubic metres). The area designated for the passenger compartment may also be used for cargo carrying purposes.

With reference to the design of VTOL Aircraft 2, the stability of the aircraft in the horizontal plane is achieved by variable thrust control from the four cardinal vertical thrust vents giving pitch and bank control as well as full vertical take-off and landing thrust control. Thrust from the horizontal engine(s) provides acceleration and retro-thrust for horizontal flight as well as directional control through 360 degrees. Whilst rapid changes in direction can be made by steering the turntable of the horizontal jet, the pilot will also be able to make minor course changes by using pitch and bank trim controls as required by varying the thrust from the four vertical vents. Alternatively, the horizontal engine can be replaced by a central vent (or vents) from the vertical engine which provides thrust downwards and is then vectored to a horizontal thrust nozzle (or nozzles) attached to the turntable and steerable through 360 degrees (via steering control in the cockpit).

With the combined use of these power configurations the aircraft can achieve rapid flight manoeuvres in all directions, including for example, rapid ascent or descent using full VTOL thrust control: rapid changes in direction in the horizontal plane from forward to reverse, from side to side, or change of direction through 90 degrees, or through 360 degrees, together with pitch and bank control, as well as spin control. The VTOL performance ability will enable the aircraft to take off vertically, or ascend at an angle of 45 degrees from the ground by using both vertical and horizontal thrust together, and then make a controlled descent at a 45 degree angle of approach to the airfield runway for landing, rather than the very shallow approach path used by conventional aircraft: this would result in a reduction of aircraft noise levels over residential areas close to airfields. In fog, it would be possible to position the aircraft directly overhead the airfield and complete a safe vertical descent onto the apron. This aircraft could also operate from much smaller airfields as it would not require the 1500 metre runway used by conventional aircraft and could also use existing helicopter landing pads on land, oil-rigs and ships. The Harrier VTOL fighter aircraft has a critical high-risk transition operation from vertical to horizontal flight when vertical thrust is vectored to horizontal thrust; this critical operation is avoided in the design disclosed because vertical thrust is constant and transition from hover to horizontal flight is immediate on application of throttle to the horizontal engine. Designed to fly with a minimum of two engines (one for vertical, one for horizontal thrust), the aircraft has a built-in safety factor because in the event of an engine failure the second engine can be used to effect an immediate emergency landing. The aircraft conforms to the aerodynamics of the disc-shape which allows minimum air-resistance or drag in horizontal flight, together with lift generated by airflow over the upper surface, and maximum air resistance in descent. Therefore, with suitable power units the aircraft will be capable of fast horizontal flight combined with the high drag or parachute effect of the disc-diameter presented against the airflow for descent and landing operations. A specific embodiment of the invention will now be described with reference to the accompanying drawings in which Figs 1 to 8 relate to VTOL Aircraft 1; and Figs 9 to 16 relate to VTOL Aircraft 2:

BRIEF DESCRIPTION OF DRAWINGS

Figure 1 shows a cross-sectional elevation of the aircraft and illustrates the vertical and horizontal propulsion systems.

Figure 2 shows a plan view of the top of the aircraft.

Figure 3 shows a plan that illustrates the contra-rotating propellers, the passenger compartment, fuel- tanks and undercarriage.

Figure 4 shows a plan of the underside of the aircraft and illustrates the jet-turbine, the circular rotor- chamber vent, control vanes, thrust deflecting flaps and undercarriage.

Figure 5 shows a cross-sectional elevation of the aircraft with an alternative design adapted for airship methods of construction.

Figure 6 shows a cross-sectional view of the fuel supply to the single turbine engine. Figure 7 shows a cross-sectional view of the fuel supply to the twin engine version. Figure 8 shows a vectored thrust valve system for the jet-turbine engine.

Figure 9 shows a typical cross-sectional elevation of VTOL Aircraft 2 and illustrates the vertical and horizontal propulsion systems. FigurelO shows a plan view of the top of the aircraft.

Figure 11 shows a plan that illustrates the central vertical thrust engine, the cooling air by-pass chamber, the fuel-tank layout, passenger compartment plan, and undercarriage bays. Figure 12 shows a plan view of the thrust vents from the vertical engine and the four secondary puffer nozzles (trim/spin controls) at the circumference.

Figure 13 shows a plan view of the underside of the aircraft and illustrates the horizontal engine attached to the turntable, the four vertical thrust vents, undercarriage bays and access ladder/hatch to the passenger compartment.

Figure 14 shows a sectional elevation of an alternative engine vent design with four vertical thrust vents and a single vent vectored to a horizontal thrust nozzle attached to a turntable for directional control. Figure 15 shows a plan view of the horizontal thrust nozzle. Figure16 shows a plan view of the vent described above.

N.B. Turntable, bearings, valves, engine fan-blades and compartments shown in the drawings are representational. Single engine positions shown may be supplanted by twin engines, or any multiple number of engines in order to provide the required power-to-weight ratio for adaptive design versions of the aircraft described herein. Similarly, jet engines may be supplanted by rocket or plasma engines suitable for future performance requirements. Single vents shown in the representations may also be adapted to twin-vents or multiple vent systems relative to the twin or multiple engine types employed to provide the required thrust relating to the invention described herein.

In Fig 1 a turbo-prop engine 14 is mounted vertically in the centre of the aircraft and is geared to turn two multi-bladed co-axial contra-rotating propellers 24 within the rotor-chamber 6, which is formed by the circular space between the passenger compartment 21 and the main engine frame 15. The propellers draw air into the circular air intake 5 at the top of the aircraft and then compress the air downward and outward through the funnel-shaped rotor-chamber to the circular exit vent 10. Air is guided into and through the rotor-chamber by flow vanes 25 and 22 which span the top and bottom of the rotor-chamber respectively and these vanes also serve as structural support frames linking the engine frame with the main body of the craft. Aerofoil vanes 23, which are mounted upon flow vanes 22, are angled into the airflow below the propellers to generate an additional lift force. Vanes 23 may also be hinged as control surfaces to effect pitch and bank control of the aircraft. Similarly, aerofoil vanes 17 are hinge-mounted beneath vanes 22 to effect directional rudder trim control of the aircraft. The said turbo-prop engine is mounted on structural engine frame 15, which is connected to the main body of the craft by structural frames 22. For servicing and repairs the central engine unit can be unbolted and completely removed from below the main body of the craft. Ancillary engine systems such as cooling plant, fuel pumps and electrical services are housed within the conical engine frame compartment 16.

Structural support frames 20 separate the internal compartments of the main body of the aircraft. The circular flight-deck 2 is supported above the central engine unit by structural frames 25 and is enclosed by hemispherical cockpit canopy 1. The top fan-shaft bearing 3 connects the top of the turboprop engine to the upper structural framework 25 and the engine intake 4 draws air from the main circular air intake 5, with the engine exhaust 26 discharging into the rotor-chamber. A lubrication point (not shown) may be installed in the top centre of fan-shaft bearing 3.

The horizontal jet turbine engine 12, is mounted to a rotatable turntable 11 which enables the pilot to turn the engine (via steering control) through 360 degrees then lock the turntable to the required course. The jet turbine is secured by a protective base-plate 13, secured to the turntable above the engine.

As shown in FigJ, provision may be made for the single jet turbine to be supplanted by twin or multiple engines connected to the central turntable 11 in order to provide additional horizontal thrust. In Fig.8, vectored thrust valve 33 (hinged to operate electrically or hydraulically) may be installed in the turbine vent to provide vectored thrust to horizontal thrust nozzle 31, or vertical thrust nozzle 32, in order to provide additional vertical thrust on take-off.

In Fig. 5 an alternative engine mounting is shown whereby the jet-turbine engine 12 is secured to a gimbal frame 29, connected to rotatable turntable 11. This allows the jet engine to be angled upward, thus directing thrust downward for vertical take-off.

Fig.2 shows the central flight-deck 2 in relation to the surrounding circular rotor air-intake 5. The rotor intake covers 27 (only one typical section shown) are housed inside the top section of the main body 8, and are hydraulically controlled from open to closed or locked into the position required by the pilot to control the amount of airflow to the rotor-chamber. The retractable undercarriage units 9 are shown in plan position in Fig.3, and have castoring main- wheels to allow free directional movement of the craft when taxiing. The space above the undercarriage bays is used to accommodate additional fuel tanks 7. The main fuel tanks 19 are situated in the area shown at the circumference of the craft. Fuel is pumped to the engines via structural frames 22. In Figs. 6 & 7, fuel and oil inflow pipes 29, which may be fitted with flow-valves as required, deliver pressurised fuel and oil to the turbine engine 12, and are installed to pass vertically through the centre of rotatable turntable 11 in order to allow the free rotation of the turntable and engine through 360 degrees of steerage in the horizontal plane.

In Fig.3, the contra-rotating propellers 24 are fitted with a variable pitch control so that fine-pitch plus high engine rpm can be selected for take-off and landing when maximum lift is required, and coarse pitch can be selected for cruising flight a lower rpm setting. The direction of the aircraft may also be controlled by varying the rpm of the propellers, allowing the resulting torque to spin the craft. Passenger compartments 21 are situated in the main annular fuselage of the aircraft and may be linked by a circular access corridor (not shown) and may have access hatches and retractable steps which allow passengers to enter and exit from the underside 18, of the craft.

A plan view of the aircraft is shown in Fig.4 illustrating the position of the jet-turbine engine 12, which is mounted between turntable 11 and base-plate 13. This plan also shows the juxtaposition of trim vanes 17 and aerofoil vanes 23 which are effective in the airflow forced by the propellers through the rotor- chamber exit vent 10. Thrust deflecting flaps 30 may be lowered into the horizontal jet-stream to provide additional lift on take-off and landing and may also be deployed as air-brakes if required.

A further application of the invention described above is illustrated in Fig. 5 with an alternative design adapted for use as an airship, employing an inert gas such as helium as a buoyancy agent, where the main body of the craft is filled with gas buoyancy chambers 28. For example a 15 metre diameter craft can accommodate 1200 cubic metres of helium gas which gives buoyancy equivalent to 1200 kg weight. (1 cubic metre of helium supports 1 kilogram weight). The craft can therefore be designed to be weightless at ground level, rather than lighter than air as a conventional airship, so that minimal thrust is required from the contra-rotating propellers to achieve vertical take-off. With the contra-rotating propellers in reverse providing a controlled downward force, existing problems of airship control and tethering on landing would be eliminated.

With reference to the design of VTOL Aircraft 2: in Fig.9 a jet engine 9/7 is mounted vertically in the centre of the aircraft by engine mounts 9/33, which are secured to the main bulkhead frames. Air is drawn into the engine intake 9/4 from the annular intake 9/5 positioned in the top central area of the aircraft. Intake covers (not shown) may be fitted within the upper surface 9/8 to slide over air intake 9/5. An impeller fan 9/34 drives air into the by-pass chamber 9/6 to provide cooling air around the engine and thrust vents via annular duct 10; the air is then expelled through open vent 9/24 at the base of the craft. Thrust from the vertical engine is equally distributed to the four vertical thrust vents 9/14, which are situated at cardinal points on plan below the engine. Valves 9/21 , positioned at the neck of each thrust vent, (where the vent joins the engine) control the amount of thrust delivered from the engine to each vent. The valves are operated by a control column, whereby thrust delivered to the fore-and-aft vents will control the pitch of the aircraft, and thrust delivered to the lateral vents will control bank. It follows from this configuration that the fore-and-aft vents need to be aligned with the flight-path of the aircraft and rapid changes in direction will therefore be limited to 90,180, and 270 degrees in either direction from the given flight-path so that these pitch and bank controls remain effective. However, more gradual course changes can be made by banking the craft to left or right, then maintaining the horizontal attitude when the course change is complete. Four secondary trim controls in the form of puffer jet-nozzles 9/12, which can be rotated to control the spin of the aircraft in each direction about its vertical axis, are situated at the circumference at cardinal points plus 45 degrees, (in order to offset the main thrust vents by 45 degrees on plan), and with jet thrust supplied from engine 9/7 to provide secondary pitch and bank trim control. The main vertical thrust vents 9/14, can be fitted with vectored thrust nozzles 9/23, to allow thrust to be directed through 180 degrees (i.e. to swivel 90 degrees each side of the vertical position): this would allow the pilot to rotate the lateral vents from vertical to horizontal thrust while using the fore-and-aft vents for vertical thrust and rudder control.

The vectored thrust nozzles 9/23 can also be rotated to spin the aircraft rapidly about its vertical axis. The top fan-shaft bearing 9/3 connects the top of the vertical engine to the upper structural framework 9/32. Alternatively, it may be preferable to have a clearance between the engine and the said upper structural frame which supports the flight-deck 9/2, enclosed by hemispherical cockpit canopy 9/1 , positioned at the top centre of the aircraft. (In this case bearing 9/3 would be omitted).

The horizontal thrust engine 9/20, is positioned centrally below vertical engine 9/7 and is mounted to a rotatable turntable 9/16 which enables the pilot to swivel the engine through 360 degrees, then lock the turntable to the required course. Cardinal points marked on the steering control will enable the pilot to make rapid course changes through 90 degree sequences in order to align the horizontal engine with the four pitch and bank control vents described above. Horizontal thrust is expelled at engine vent 9/15. The said engine is secured by a protective base-plate 9/19, connected to the turntable above the engine. The turntable is bolted to engine mountings 9/22, which are secured to the main bulkhead frames. The central engine units may be completely disconnected from the main-frame of the aircraft for maintenance. Provision can be made for the said horizontal engine(s) to have a vectored thrust vent fitted to give additional thrust on take-off.

The main fuel tanks 9/31 , with filler pipes 9/30, are situated in the main body of the craft and positioned around the central engine chamber. Fuel is pumped to the engines via structural frames 9/22 and 9/33, and the tanks are shaped to ensure gravity feed to the lower outlet pipes: fuel tanks are linked together to ensure an even distribution of fuel weight around the centre of gravity of the craft as fuel is consumed. Fuel and lubricant pipes 9/18 (fitted with flow valves as required) which supply horizontal engine(s) 9/20, are installed to pass vertically through the centre of turntable 9/16 in order to allow the free movement of turntable and engine. Ancillary engine systems such as cooling plant, fuel pumps and electrical services together with turntable motor and hydraulics may be housed within the circular engine frame compartment 9/17. Reserve fuel tanks, cargo or supplies may be accommodated in compartments 9/9, above the undercarriage bays. Retractable undercarriage units 9/11 are fitted with castored main-wheels to allow free movement when taxiing, and bay doors 9/13, (which may be supplanted by sliding doors). Passenger compartment 9/29 is situated in the main body of the craft and may have windows/port-holes (not shown) with retractable access hatch/ladders 9/25 fitted into the lower body 9/26 of the craft. In the fire rescue version personnel enter the passenger compartment directly through the upper surface 9/8 of the craft, via foot-plate 9/27, and hatch 9/28, (which may be supplanted by sliding doors).

In FigurelO a plan view of the top of the aircraft shows the annular air intake 10/5, structural frames 10/32 which support the central flight-deck 10/2. Fuel tank filler pipes 10/30 are installed in the upper surface 10/8 of the aircraft. Personnel rescue/access hatches 10/27 and 10/28, (hinged or sliding open) are positioned between the internal bulkhead formers (not shown) of the aircraft.

In Figure 11 a plan view illustrates the central vertical thrust engine 11/7, with intake 11/4, impeller-fan 11/34, engine mounts 11/33, and cooling chamber 11/6. Fuel tanks 11/31 are installed around the central engine(s). Undercarriage bays 11/11 are situated at cardinal points on plan: however provision may be made for the minimum practical number of three bays positioned on plan at 120 degree intervals. The passenger compartments 11/29 are circular, extending inwards from the circumference of the aircraft and may be linked by an access corridor. Compartment 11/9 above the undercarriage bay may be used for storage.

In Figure 12, a plan view shows the four vertical thrust vents 12/14, which extend outward and downward from the base of the central vertical engine 12/7. Vectored thrust units 12/23 which swivel through 180 degrees from horizontal are fitted to provide additional vertical thrust as well as rudder control. Cooling chamber 12/6 surrounds the engine and has a lower exit vent 12/24 at the base of the craft. Four puffer jets 12/12, supplied with thrust either from the central engine or from separate compressors, are situated on the diagonals equally between the main thrust vents and provide additional pitch, bank, and spin trim control from rotatable nozzles.

In Figure 13 a plan view of the underside 13/26 of the aircraft shows horizontal thrust engine 13/20 with base-plate 13/19, attached to turntable 13/16 situated centrally below engine compartment 13/17 in relation to the vertical thrust vents 13/14. Typical positions for the personnel access ladder/hatch 13/25 are given close to the undercarriage bays 13/11.

Figure 14 illustrates a sectional elevation of an alternative engine vent design where four main cardinal vertical thrust vents 14/14 extend from the base of vertical engine 14/7, with the addition of a central vent 14/36, delivering vectored thrust to horizontal nozzle 14/37. This nozzle is incorporated within vectored thrust unit 14/35, which is connected to turntable 14/16. This enables thrust from nozzle 14/37 to be swivelled through 360 degrees in order to steer the craft. Flow valves 14/21 are fitted to each vent to control thrust. Figure 15 shows a plan of vectored thrust unit 15/35 with nozzle 15/37.

Figure 16 illustrates a plan of the alternative engine vent design described above with the additional vent 16/36, vectored thrust unit 16/35 and nozzle 16/37. A circular vent cowling 16/38 may be fitted to stream the airflow beneath the vent system.

Whereas the essential features disclosed in the above invention relate to the juxtaposition of vertical and horizontal engines and related control vents fitted to a disc-shaped body that exhibits uniform aerodynamics in any given direction of horizontal flight, the invention also allows for the same engine configuration to be adapted for use with different types and shapes of flying wing, for example: a square, oblong or triangular shape which may have either sharp or rounded corners, and which may be aerodynamically efficient at supersonic speeds. The invention allows for the jet engine systems shown to be supplanted by rocket engines where the design disclosed may be adapted for use as a Space Operating Vehicle (with passenger compartment re-designated to fuel-tank space).

A NEW FLIGHT TRAJECTORY FOR SPACE OPERATING VEHICLES is now possible with this versatile design as, after take-off, the disc-shaped craft can accelerate through the lower atmosphere with full horizontal-thrust to maximum speed, then both vertical and horizontal thrust can be applied equally (giving a thrust force acting at 90 degrees) to give the disc-shape a flight-path approximately 45 degrees from horizontal. At this stage, the four vertical thrust vents can be vectored horizontal to combine with the horizontal power units in order to achieve escape velocity. On re-entry, full vertical thrust combined with the wide area of the disc-shape presented perpendicular to the descent flight-path, will give a very high-drag profile, or resistance against the airflow, until the craft slows down to normal atmospheric flight-speed, when the horizontal flight attitude is resumed as the craft skims through the upper levels of the atmosphere, conserving a small amount of remaining fuel for retro-thrust from the horizontal engines prior to the final hover and landing.

BEST MODE FOR CARRYING OUT THE INVENTION:

The aircraft is designed for construction using composite GRP and carbon-fibre/ Kevlar reinforced materials that are both strong and light in weight, with the intention of making the hull as a monocoque casting bonded onto main bulkhead formers. This construction will enable the craft to exhibit a low radar profile. Alternatively, shaped or spun aluminium-alloy panels can be riveted onto light-weight aluminium-alloy formers to complete the surfaces of the annular fuselage using the conventional method of aircraft construction.

Depending upon the size of the aircraft under construction, a variable number of bulkhead formers are fixed to radiate equally from around circular ring-frames which define the top and bottom of the central cylindrical rotor-chamber. The bulkhead formers are then secured to another circular ring-frame that defines the circumference of the annular fuselage. Circular stringers are slotted into the bulkhead formers to form the framework of the outer body of the aircraft, to which pre-formed sheets of aluminium-alloy or GRP are then applied as an outer skin. The engines are bolted to engine bearing mountings that are connected to the main fuselage formers. A conical engine cowling is fitted around the central vertical engine and the inside of the rotor-chamber is clad with a similar material, after the fuel tanks and ancillary services have been fitted to the main annular fuselage.

A turntable is fixed to engine bearing mountings below the central vertical engine and the horizontal thrust engine is then secured to the turntable. The flight-deck is supported at the top-centre of the aircraft by upper structural formers that are linked to the main bulkhead formers. Flight control systems are linked to the engines via the structural formers and the engine mounting struts.

Although the aircraft is disc-shaped and aerodynamically uniform in all directions of flight, requirements of the flight control systems dictate the need to have one main direction for forward flight. Therefore the cockpit layout and passenger seating plan will relate to the fore-and-aft centre-line of the aircraft control systems, so that the majority of passengers/personnel will be aligned with the direction of flight.

INDUSTRIAL APPLICABILITY

The invention disclosed offers the aviation industry a completely new design concept for VTOL aircraft which could be produced for the Air Transport Market, (including airliner and helicopter market) as well as the General Aviation Market (light aircraft, family touring, air-taxi market) and to fulfil new roles in safety and rescue operations.

The versatility of the design gives every opportunity for world-wide commercial application in the aviation industry.

Claims

1. An aerodynamic disc-shaped VTOL aircraft wherein a central turboprop engine turning contra- rotating co-axial propellers is mounted in the vertical axis position above a turbojet engine, or engines, mounted horizontally on a central turntable unit which can be steered through 360 degrees; the said turbojet engines having vectored thrust nozzles to provide additional vertical thrust for VTOL operations.

2. A VTOL aircraft as claimed in Claim 1, wherein contra-rotating propellers push air downwards into a circular funnel shaped rotor-chamber, compressing the air to provide vertical take-off thrust from a lower annular vent.

3. A VTOL aircraft as claimed in Claims 1 to 2, having rotor intake covers which, when closed, prevent the inflow of air through the rotor-chamber thereby allowing the propellers to rotate in a partial vacuum.

4. A VTOL aircraft as claimed in Claims 1 to 3, wherein aerodynamic control vanes are positioned in the airflow from the propellers, within or at the base of, a rotor-chamber to effect pitch, roll and yaw control, as well as to generate an additional lift force: and wherein thrust deflecting flaps may be lowered from the underside of the aircraft.

5. An aerodynamic disc-shaped aircraft wherein a central jet or rocket engine (or engines), delivers thrust downwards to four vertical thrust vents (which may have vectored thrust nozzles) situated at cardinal points below the said engine, together with a central horizontally mounted jet or rocket engine (or engines) delivering horizontal thrust and fixed to a turntable pod which is steerable through 360 degrees and is situated centrally below the vertical thrust engine (or engines).

6. A VTOL aircraft as claimed in Claim 5, wherein the central horizontal engine (or engines) is replaced by the addition of a central thrust vent (or vents), delivering vectored thrust from the vertical engine/s to a horizontal nozzle withjn a vectored thrust unit which is connected to a turntable and rotates through 360 degrees in order to steer the craft.

7. A VTOL aircraft as claimed in Claims 5 and 6, wherein the passenger compartment is re-designated mostly to fuel-tank space, the engine and vent systems upgraded for rocket or plasma power systems and the hull structure reinforced to achieve the performance parameters required for use as a space operating vehicle.

8. An aerodynamic disc-shaped VTOL aircraft as claimed in Claims 1 to 4, adapted for use as an airship, wherein a central turboprop engine turning contra-rotating co-axial propellers is mounted in the vertical axis position above a turbojet engine, or engines, mounted horizontally below a central turntable unit which can be steered through 360 degrees; the said turbojet engine/s being fitted with a gimbal frame so that the engine can be tilted about a horizontal axis which is perpendicular to its longitudinal axis.

VTOL aircraft as claimed in Claim 8, wherein the main body of the craft may contain gas buoyancy chambers.

A VTOL aircraft as claimed in Claims 1 to 6, wherein a circular passenger compartment, as well as payload, fuel-tanks and weapon-bays are incorporated in the main circular body of the craft.

A VTOL aircraft as claimed in Claims 1 to 9, wherein fuel tanks are incorporated around the inner or outer circumference of the main annular body of the craft.

A VTOL aircraft as claimed in Claims 1 to 11 , which has a central flight-deck supported by a structural frame and situated above central vertical and horizontal mounted engines, and is separate from the passenger compartment.

A VTOL aircraft as claimed in Claims 1 to 12, wherein the central engine frame is constructed as a cone-shape with a concave base, and wherein the said engine frame can be detached from the main outer body of the craft.

A VTOL aircraft, airship or space operating vehicle as claimed in Claims 1 to 13, wherein passenger access hatches and port-holes or windows are installed in either upper or lower surfaces of the main body of the craft.