Enhanced taxi control for rigid rotors

Patent metadata

Field	Value
Publication number	US-10831193-B2
Application number	US-201715812707-A
Country	US
Kind code	B2
Filing date	Nov 14, 2017
Priority date	Nov 14, 2017
Publication date	Nov 10, 2020
Grant date	Nov 10, 2020

Abstract

An aircraft includes an airframe having an aircraft longitudinal axis and a main rotor system supported by the airframe. The main rotor system is rotatable about an axis of rotation. The airframe is tiltable relative to a ground surface to form a non-zero tilt angle between the aircraft longitudinal axis and the ground surface.

First claim

What is claimed is:

1. An aircraft comprising:
an airframe having an aircraft longitudinal axis;
at least one landing gear assembly coupled to the airframe; and
a main rotor system supported by the airframe, the main rotor system being rotatable about an axis of rotation;
wherein the airframe is tiltable relative to a ground surface in response to adjusting a vertical length of the at least one landing gear assembly to form a non-zero tilt angle between the aircraft longitudinal axis and the ground surface, and
wherein, when the airframe is tilted, a nose end of the airframe is oriented lower than a tail end of the airframe, the nose end of the airframe being positioned forwardly of the tail end of the airframe in a direction of travel.

2. The aircraft of claim 1 , wherein when the airframe has a non-zero tilt angle, operation of the main rotor system generates a forward thrust.

3. The aircraft of claim 1 , wherein the main rotor system is a rigid rotor system.

4. The aircraft of claim 1 , wherein the main rotor system further comprises:
an upper rotor system rotatable about the axis of rotation in a first direction; and
a lower rotor system rotatable about the axis of rotation in a second direction.

5. The aircraft of claim 1 , wherein the at least one landing gear assembly includes a mechanism for transforming the at least one landing gear.

6. The aircraft of claim 1 , wherein the at least one landing gear assembly further comprises:
a nose landing gear assembly disposed near the nose end of the airframe; and
at least one rear landing gear assembly disposed near the tail end of the airframe.

7. The aircraft of claim 6 , wherein the configuration of the nose landing gear assembly and the at least one rear landing gear assembly are varied independently.

8. The aircraft of claim 6 , wherein the non-zero tilt angle is generated in response to varying the configuration of the nose landing gear assembly.

9. The aircraft of claim 6 , wherein the non-zero tilt angle is generated in response to adjusting the vertical height of the at least one rear landing gear assembly.

10. The aircraft of claim 6 , wherein the non-zero tilt angle is generated in response to adjusting the vertical height of both the nose landing gear assembly and the at least one rear landing gear assembly.

11. The aircraft of claim 10 , wherein the non-zero tilt angle is generated by reducing a vertical length of the nose landing gear assembly and by increasing a length of the at least one rear landing gear assembly.

12. A method of taxiing an aircraft comprising:
determining a desired tilt angle of the aircraft; and
tilting an airframe of the aircraft to achieve the desired tilt angle, wherein titling the airframe includes varying configuration of at least one landing gear assembly of the aircraft by adjusting a vertical length of the at least one landing gear assembly; and
operating a main rotor system of the aircraft while the airframe of the aircraft is at the desired tilt angle to generate a forward thrust,
wherein tilting the airframe includes tilting the airframe to orient a nose end of the airframe lower than a tail end of the airframe, the nose end of the airframe being positioned forwardly of the tail end of the airframe in a direction of travel.

13. The method of claim 12 , wherein the desired tilt angle is up to 45 degrees.

14. The method of claim 13 , wherein the desired tilt angle is between 4 degrees and 6 degrees.

15. The method of claim 12 , wherein varying a configuration of the at least one landing gear assembly includes increasing a vertical length of the landing gear assembly.

16. The method of claim 12 , wherein varying a configuration of the at least one landing gear assembly includes decreasing a vertical length of the landing gear assembly.

17. The method of claim 12 , wherein varying a configuration of the at least one landing gear assembly includes increasing a vertical length of a first landing gear assembly and decreasing a vertical length of a second landing gear assembly.

18. The method of claim 12 , wherein the at least one landing gear assembly further comprises a mechanism operable to vary the configuration of the at least one landing gear assembly in response to a signal.

Assignees

• Sikorsky Aircraft Corp

Inventors

• Lappos Nicholas D
• Thornberg Christopher A

Classifications

• B64C27/10 Primary

  arranged coaxially · CPC title

• G05D1/0083 Primary

  to help an aircraft pilot in the rolling phase · CPC title

• B64C25/08

  non-fixed, e.g. jettisonable · CPC title

• B64C25/00

  Alighting gear (air-cushion alighting gear B60V3/08) · CPC title

• B64C2025/325

  specially adapted for helicopters · CPC title