# US 2021/0276690 A1 · Pivoting sail fairing

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- Number: US 2021/0276690 A1
- Document ID: US20210276690A1
- Status: Published application
- Kind: A1
- Application number: 16/809,936
- Filed: 2020-03-05
- Published: 2021-09-09
- Earliest claimed: 2020-03-05
- Assignees: Lockheed Martin Corporation
- Applicants: Lockheed Martin Corporation
- Inventors: Jonathan Witt
- Web page: https://patentgrep.com/patent/US20210276690A1

## CPC

- B64C 7/00: Structures or fairings not otherwise provided for
- B64C 27/10: arranged coaxially
- B64C: AEROPLANES; HELICOPTERS

## Abstract

According to an aspect, a pivoting sail fairing system includes a rotatable fairing, for rotation about a first axis of rotation of an aircraft, that includes a housing that defines a compartment arranged inward from the housing, the housing including a first orifice on a first surface and a second orifice on a second surface of the housing, and a first actuator mounted on a surface of the compartment inward from the housing

## Claims

### Claim 1

A fairing system, the system comprising:
a rotatable fairing, for rotation about a first axis of rotation of an aircraft, comprising a housing that defines a compartment arranged inward from the housing, the housing comprising a first orifice on a first surface and a second orifice on a second surface of the housing; and
a first actuator mounted on a surface of the compartment inward from the housing.

### Claim 2 (depends on 1)

The system of claim 1, wherein the first actuator is a spring-based actuator.

### Claim 3 (depends on 1)

The system of claim 1, wherein the first actuator is an electronically controlled actuator.

### Claim 4 (depends on 3)

The system of claim 3, further comprising a sensor arranged on an airframe of the aircraft,
wherein an angle of rotation of the fairing is based in part on data collected by the sensor.

### Claim 5 (depends on 1)

The system of claim 1, wherein the rotatable fairing has an airfoil contour.

### Claim 6 (depends on 1)

The system of claim 1, further comprising a second actuator.

### Claim 7 (depends on 6)

The system of claim 6, wherein the first actuator and the second actuator are a same type of actuator.

### Claim 8 (depends on 6)

The system of claim 6, wherein the first actuator is a different type of actuator than the second actuator.

### Claim 9 (depends on 9)

The system of claim 9, wherein the first actuator is a spring-based actuator and the second actuator is a piston-based actuator.

### Claim 10

A rotary wing aircraft comprising:
a rotor shaft;
a rotatable fairing connected to the rotor shaft for rotation about a first axis of rotation;
a first actuator mounted to the rotor shaft and in operable communication with the fairing,
wherein the first actuator is operable to adjust an angle of rotation of the fairing about the first axis of rotation.

### Claim 11 (depends on 10)

The rotary wing aircraft of claim 10, wherein a leading edge of the rotatable fairing is arranged relative to the rotor shaft.

### Claim 12 (depends on 10)

The rotary wing aircraft of claim 10, wherein the rotatable fairing is connected to a standpipe between a first rotor system and a second rotor system.

### Claim 13 (depends on 10)

The rotary wing aircraft of claim 10, wherein the first rotor system comprises a first hub fairing, and the second rotor system comprises a second hub fairing.

### Claim 14 (depends on 10)

The rotary wing aircraft of claim 10, wherein the first actuator is operable to resist a rotation, caused by an external force, of the fairing up to a threshold amount of the external force.

### Claim 15 (depends on 10)

The rotary wing aircraft of claim 10, wherein the first actuator is operable to return to a resting position in response to an external force being below a threshold amount.

### Claim 16 (depends on 10)

The rotary wing aircraft of claim 10, wherein the rotary wing aircraft has a dual, counter-rotating, coaxial rotor system.

### Claim 17 (depends on 10)

The rotary wing aircraft of claim 10, wherein the fairing is connected to the rotor shaft via a standpipe.

### Claim 18 (depends on 17)

The rotary wing aircraft of claim 17, wherein the first actuator is attached to the standpipe.

### Claim 19 (depends on 17)

The rotary wing aircraft of claim 17, wherein the fairing is connected to the standpipe via a first bearing and a second bearing.

### Claim 20 (depends on 10)

The rotary wing aircraft of claim 10, further comprising
a second actuator,
wherein the first and second actuators are connected to the rotor shaft via a standpipe.