Aircraft having dual rotor-to-wing conversion capabilities

Patent metadata

Field	Value
Publication number	US-10407169-B2
Application number	US-201615251110-A
Country	US
Kind code	B2
Filing date	Aug 30, 2016
Priority date	Aug 30, 2016
Publication date	Sep 10, 2019
Grant date	Sep 10, 2019

Abstract

A tail sitter aircraft includes a fuselage having a forward portion and an aft portion. The forward portion of the fuselage includes first and second rotor stations. A first rotor assembly is positioned proximate the first rotor station. A second rotor assembly is positioned proximate the second rotor station. A tailboom assembly extends from the aft portion of the fuselage and includes a plurality of landing members. A pusher propeller extends from the tailboom assembly. In a vertical takeoff and landing mode, the first and second rotor assemblies rotate about the fuselage to provide vertical thrust. In a forward flight mode, rotation of the pusher propeller provides forward thrust and the first and second rotor assemblies are non-rotatable about the fuselage forming a dual wing configuration to provide lift.

First claim

What is claimed is:

1. A tail sitter aircraft comprising:
a fuselage having a forward portion and an aft portion, the forward portion including first and second rotor stations;
a first rotor assembly positioned proximate the first rotor station;
a second rotor assembly positioned proximate the second rotor station;
a tailboom assembly extending from the aft portion of the fuselage, the tailboom assembly including a plurality of control surfaces and a plurality of landing members; and
a pusher propeller extending from the tailboom assembly;
wherein, the plurality of control surfaces are forward of the pusher propeller;
wherein, the plurality of landing members are coupled to the plurality of control surfaces and extend aftward to terminate aft of the pusher propeller;
wherein, in a vertical takeoff and landing mode, the first and second rotor assemblies rotate about the fuselage to provide vertical thrust;
wherein, in a forward flight mode, rotation of the pusher propeller provides forward thrust and the first and second rotor assemblies are non-rotatable about the fuselage forming a dual wing configuration to provide lift; and
wherein, the first and second rotor assemblies include rotor blades and, in a storage mode, the rotor blades of the first and second rotor assemblies are folded aftward toward the pusher propeller such that the rotor blades are generally parallel with a longitudinal fuselage axis to reduce aircraft geometry.

2. The tail sitter aircraft as recited in claim 1 wherein the first and second rotor assemblies each further comprise two rotor blades.

3. The tail sitter aircraft as recited in claim 1 wherein the first and second rotor assemblies each have cyclic control and collective control.

4. The tail sitter aircraft as recited in claim 1 wherein the first and second rotor assemblies are generally torque matched in vertical takeoff and landing mode.

5. The tail sitter aircraft as recited in claim 1 wherein the first and second rotor assemblies rotate in opposite directions in vertical takeoff and landing mode.

6. The tail sitter aircraft as recited in claim 1 wherein the pusher propeller further comprises a fixed pitch pusher propeller.

7. The tail sitter aircraft as recited in claim 1 wherein the pusher propeller is not powered in vertical takeoff and landing mode.

8. The tail sitter aircraft as recited in claim 1 wherein the dual wing configuration further comprises an x-wing configuration.

9. The tail sitter aircraft as recited in claim 1 wherein the dual wing configuration provides roll control in forward flight mode.

10. The tail sitter aircraft as recited in claim 1 further comprising an engine operable to provide torque and rotational energy to the first and second rotor assemblies and the pusher propeller.

11. The tail sitter aircraft as recited in claim 1 wherein the engine further comprises an electrical motor.

12. The tail sitter aircraft as recited in claim 1 further comprising a first engine operable to provide torque and rotational energy to the first and second rotor assemblies and a second engine operable to provide torque and rotational energy to the pusher propeller.

13. The tail sitter aircraft as recited in claim 1 wherein, in a storage mode, the aftward folded rotor blades of the first rotor assembly are clocked about ninety degrees relative to the aftward folded rotor blades of the second rotor assembly.

14. A method of operating a tail sitter aircraft comprising:
supporting a fuselage in a generally vertical attitude on a surface with a plurality of landing members of a tailboom assembly, the tailboom assembly including a plurality of control surfaces;
folding rotor blades of first and second rotor assemblies aftward toward a pusher propeller such that the rotor blades are generally parallel with a longitudinal fuselage axis to reduce aircraft geometry in a storage mode;
rotating first and second rotor assemblies about the fuselage to provide vertical thrust in a vertical takeoff and landing mode;
rotating the pusher propeller to provide forward thrust in a forward flight mode; and
forming a dual wing configuration with the first and second rotor assemblies by preventing rotation of the first and second rotor assemblies about the fuselage to provide lift in the forward flight mode;
wherein, the plurality of control surfaces are forward of the pusher propeller; and
wherein, the plurality of landing members are coupled to the plurality of control surfaces and extend aftward to terminate aft of the pusher propeller.

15. The method as recited in claim 14 wherein rotating the first and second rotor assemblies about the fuselage to provide vertical thrust further comprises operating the first and second rotor assemblies responsive to cyclic control and collective control.

16. The method as recited in claim 14 wherein rotating the first and second rotor assemblies about the fuselage to provide vertical thrust further comprises generally torque matching the first and second rotor assemblies.

17. The method as recited in claim 14 wherein rotating the first and second rotor assemblies about the fuselage to provide vertical thrust further comprises rotating the first and second rotor assemblies in opposite directions.

18. The method as recited in claim 14 wherein forming the dual wing configuration with the first and second rotor assemblies further comprises forming an x-wing configuration with the first and second rotor assemblies.

19. The method as recited in claim 14 further comprising performing a dual rotor-to-wing conversion of the first and second rotor assemblies by stopping the rotation of the first and second rotor assemblies about the fuselage and adjusting an angle of attack of each rotor blade of the first and second rotor assemblies.

20. The method as recited in claim 14 further comprising performing a dual wing-to-rotor conversion of the first and second rotor assemblies by reengaging rotation of the first and second rotor assemblies about the fuselage.

Assignees

• Bell Helicopter Textron Inc
• Bell Textron Inc

Inventors

• Groninga Kirk Landon
• Robertson Daniel Bryan
• Stamps Frank Bradley

Classifications

• B64C11/00

  Propellers, e.g. of ducted type; Features common to propellers and rotors for rotorcraft · CPC title

• B64C27/24

  with rotor blades fixed in flight to act as lifting surfaces · CPC title

• B64C27/50

  Blades foldable to facilitate stowage of aircraft · CPC title

• B64C25/52

  Skis or runners · CPC title

• B64C29/02 Primary

  having its flight directional axis vertical when grounded · CPC title