Free Wing Multirotor Transitional S/VTOL Aircraft

Abstract

An improved aircraft design to harness advantages of vertical or short-takeoff and landings (V/STOL) and efficient horizontal flight. Configuration improves aircraft flight stability and efficiency in flight profiles: (1.) vertical flight; (2.) transition to and from horizontal flight and; (3.) horizontal flight on wings. The aircraft is capable of stable flight at any airspeed from hover to its maximum designed speed. It has the possibility of a controlled emergency landing using autorotation or, wings or, a combination of the two. Aircraft design includes: multiple thrust sources and, wings free to rotate on a spanwise axis. Wing rotation is independent—not coupled—with either the fuselage or, the thrust sources. Wing configurations include single, tandem or, multiple sets. Wings are coupled each other such that rotation induced in one wing affects rotation in all wings. Thrust sources are directed vertically during hover and some degree forward of vertical for horizontal flight. Thrust sources for vertical and horizontal flight can be the same rotors, such as in tilt-rotor configurations; or, divided between vertical flight rotors and horizontal flight rotors, such is in lift and cruise (a.k.a. lift and thrust) configurations.

Claims

1. An aircraft comprising wings, fuselage, vertical stabilizer, multiple thrust producing rotors, a method to change thrust direction from vertical to horizontal wing sets can be single, tandem or multiple sets series wings can be mounted on same structure as rotors or separate spars wings are free to rotate on a span wise axis, the wings are coupled with each other in such that a rotation induced in one wing affects all wings the wings are balanced with the centre of mass some distance behind the axis of rotation; thrust producing rotors are configured with 3 or more propellers, configured in a geometry to provide the stability of a multi-rotor type aircraft; thrust producing rotors are mounted on structures attached to the fuselage thrust from rotors are variable through change in individual propeller pitch or change in individual rotor rpm stability in vertical flight is achieved through variation of thrust from different rotors stability in transitional and slow flight is achieved through a combination of variation in thrust of different rotors and characteristics of freely rotating wings control of flight in horizontal is achieved either through aerodynamic control surfaces or vector thrust of the rotors thrust producing rotors are separated in the horizonal plane with a geometry to maximize vertical flight stability propellers are configured to 1. tilt or rotate through a range of motion or, 2. vertical flight rotors with separate horizontal propeller or 3. combination of above 2 configurations; a method to drive the rotors which may include but not limited to 1. electric drive or, 2. hydraulic drive or, 3. mechanical drive from an internal combustion engine or, 4. some combination of the aforementioned the fuselage maintains a generally horizontal attitude throughout all flight regimes a fuselage containing power systems, fuel, and payload;

2. The aircraft in claim 1 wherein the wings are mounted between parallel booms and the propellers and drives are mounted on spars outside the booms or, on the booms

3. The aircraft in claim 1 wherein the wing rotation is restricted by mechanical or electronic means within a maximum and minimum range

4. The aircraft in claim 1 wherein the wings are separated in the horizontal plane, such that the aft mounted wing is higher or lower from the centreline than the front wing

5. The aircraft of claim 1 wherein the propellers are variable pitch

6. The aircraft of claim 1 wherein the wings do not extend to the full span of the spar, such that the wings are not in the airflow of the propeller

7. The aircraft of claim 1 wherein the wings are coupled electronically

8. The aircraft of claim 1 wherein the relative angle of attack of fore and aft wings can be adjusted

9. The aircraft of claim 1 wherein the relative angle of attack of left and right wings can be adjusted

10. An aircraft comprising of 2 or more wings mounted between twin booms, propellers mounted in multirotor configuration are mounted so that propwash from the propellers do not spill over the wings 10

Description

BRIEF DESCRIPTION OF DRAWINGS

[0024] FIG. 1. Orthogonal view of aircraft with propellers positioned for vertical flying

[0025] FIG. 2. Orthogonal view of aircraft with propellers positioned for horizontal flying

[0026] FIG. 3. Orthogonal view of aircraft, detail showing wing coupling

[0027] FIG. 4. Side view of aircraft with propellers positioned for vertical ying

[0028] FIG. 5. Side view of aircraft with propellers positioned for horizontal flying

[0029] FIG. 6. Side view of forward wing in horizontal flying mode, detail showing coupling, center of mass approximate position behind axis of rotation. With horizontal airflow over its surface the wing has in a generally horizonal attitude. Motor is rotation is independent from wing which rotates freely.

[0030] FIG. 7. Side view of forward wing in vertical flying mode, detail showing coupling, center of mass approximate position behind axis of rotation. Without horizontal airflow over its surface the wing hangs in a generally vertical attitude. Motor is rotation is independent from wing which rotates freely.

[0031] FIG. 8. Side view of wings assembly, detail showing wing coupling

[0032] FIG. 9. Side view of wing assembly, detail showing wing coupling capable of adjusting relative angle of attack between fore and aft wings

DETAILED DESCRIPTION OF THE DRAWINGS

[0033] FIGS. 1-9 illustrate aircraft components in vertical flying and horizontal flying mode. Orthogonal views show propellers 101, 102, 103 104; electric motors driving propellers 105, 106, 107, 108; incident adjustable or free wings 109, 110, 111, 112; flight controls, aileron, aps or flaperons 113, 114, 115, 116; vertical/horizontal stabilizer 117, 118; elevator/rudder 119, 120; forward wing bridge couples wing rotation left and right wing sets 121; right and left side fore/aft wing connectors couples fore and aft wing. rotation 122, 124; aft wing bridge couples wing rotation left and right wing sets 123; prime power source, electronics bay, payload 125; Slot through which wing bridge transits fuselage, contains stop for wing positions top and bottom 126; Spar holding motors/spanwise axis of wing 127, 128; Approximate location of center of mass of free wing 130; Control system to adjust relative angle of attack between fore and aft wings 131; Linkage to aft wing 132; Linkage to fore wing 133; Fore wing 134; aft wing 135