Passenger aircraft with a downwardly foldable wing tip device

Patent metadata

Field	Value
Publication number	US-10189557-B2
Application number	US-201515301858-A
Country	US
Kind code	B2
Filing date	Apr 2, 2015
Priority date	Apr 4, 2014
Publication date	Jan 29, 2019
Grant date	Jan 29, 2019

Abstract

A passenger aircraft including a wing (1) and a wing tip device (3). The wing tip device (3) is moveable between a flight configuration for use during flight and a ground configuration for use during ground-based operations. In the ground configuration the wing tip device is folded downwardly from the flight configuration such that the span of the aircraft is reduced. The wing tip device (3) is connected to the wing along a hinge (9) defining a hinge line (11). The hinge (9) may be arranged to prevent the wing tip device (3) rotating upwardly beyond the flight configuration. The hinge line (11) may be orientated at an angle to the flight direction such that the wing tip device (3) presents a larger frontal area when it is in the ground configuration than when it is in the flight configuration, such that aerodynamic forces urge it to rotate about the hinge line (11) away from the ground configuration and towards the flight configuration.

First claim

The invention claimed is:

1. A passenger aircraft comprising a wing, the wing having a wing tip device at the tip thereof, wherein the wing tip device is moveable between:
i. a flight configuration for use during flight, and
ii. a ground configuration for use during ground-based operations, in which ground configuration the wing tip device is folded downwardly from the flight configuration such that the span of the aircraft is reduced, and
wherein the wing tip device is connected to the wing along a hinge defining a hinge line, the hinge being arranged to allow the wing tip device to rotate about the hinge line between the flight configuration and the ground configuration, but to prevent the wing tip device rotating upwardly beyond the flight configuration;
wherein the hinge line is orientated at an angle to a flight direction such that the wing tip device presents a larger frontal area when in the ground configuration than when in the flight configuration, and such that during forward motion of the aircraft, aerodynamic forces act on the wing tip device to allow the wing tip device to rotate away from the ground configuration and towards the flight configuration under the action of the aerodynamic forces, and
wherein the aircraft further comprises an actuator for moving the wing tip device from the ground configuration to the flight configuration, the actuator having a capacity of less than that required for moving the wing tip device in the absence of the aerodynamic forces.

2. The passenger aircraft according to claim 1 , wherein during flight, with the wing tip device in the flight configuration, the aerodynamic forces acting on the wing tip device are such that the wing tip device is urged away from rotating back to the ground configuration.

3. The passenger aircraft according to claim 1 , wherein the wing and the wing tip device comprise respective abutment surfaces, and the hinge is configured such that in the flight configuration, the abutment surfaces of the wing tip device and the wing abut one another thereby blocking further rotation of the wing tip device upwardly beyond the flight configuration.

4. The passenger aircraft according to claim 3 , wherein during flight, with the wing tip device in the flight configuration, a bending moment generated about the hinge line is reacted against the abutment surface of the wing.

5. The passenger aircraft according to claim 1 , wherein the aircraft comprises a lock configured to lock the wing tip device when the wing tip device is in the flight configuration, the lock being arranged to prevent rotation of the wing tip device from the flight configuration to the ground configuration.

6. The passenger aircraft according to claim 5 wherein the lock is rated to prevent the rotation of the wing tip device during negative-g flight over a negative-g flight envelope.

7. The passenger aircraft according to claim 5 , wherein the lock is arranged to be substantially free from loads during positive-g flight.

8. The passenger aircraft according to claim 1 wherein the wing comprises a multiplicity of wing ribs orientated at an angle to the direction of flight, and the hinge line is orientated parallel to the wing ribs.

9. A method of operating an aircraft, the aircraft comprising a wing, the wing having a wing tip device at the tip thereof, wherein the wing tip device is moveable between:
i. a flight configuration for use during flight, and
ii. a ground configuration for use during ground-based operations, in which ground configuration the wing tip device is folded downwardly from the flight configuration such that the span of the aircraft is reduced, and
wherein the wing tip device is connected to the wing along a hinge defining a hinge line, the hinge being arranged to allow the wing tip device to rotate about the hinge line between the flight configuration and the ground configuration, but to prevent the wing tip device rotating upwardly beyond the flight configuration,
such that during forwards motion of the aircraft, and wherein with the wing tip device in the ground configuration, aerodynamic forces acting on the wing tip device during forwards motion of the aircraft are such that the wing tip device is allowed to rotate about the hinge line away from the ground configuration and towards the flight configuration under the action of said forces; and
wherein the aircraft further comprises an actuator for moving the wing tip device from the ground configuration to the flight configuration, the actuator having a capacity of less than that required for moving the wing tip device in the absence of the aerodynamic forces, and
wherein the method comprises the steps of:
i. having the wing tip device in the ground configuration when the aircraft is about to start a take-off run,
ii. starting the take-off run, and
iii. allowing the wing tip device to rotate from the ground configuration towards the flight configuration, at least some of that movement being effected as a result of the aerodynamic forces on the wing tip device during take-off.

10. The method according to claim 9 wherein the hinge line is orientated at an angle to the flight direction such that the wing tip device presents a larger frontal area when it is in the ground configuration than when it is in the flight configuration.

11. The method according to claim 9 , further comprising the step of locking the wing tip device in the flight configuration when the wing tip device reaches that flight configuration.

12. A method of operating an aircraft, the aircraft comprising a wing, the wing having a wing tip device at the tip thereof, wherein the wing tip device is moveable between:
i. a flight configuration for use during flight, and
ii. a ground configuration for use during ground-based operations, in which ground configuration the wing tip device is folded downwardly from the flight configuration such that the span of the aircraft is reduced, and
wherein the wing tip device is connected to the wing along a hinge defining a hinge line, the hinge being arranged to allow the wing tip device to rotate about the hinge line between the flight configuration and the ground configuration, but to prevent the wing tip device rotating upwardly beyond the flight configuration,
such that during forwards motion of and wherein with the wing tip device in the ground configuration, aerodynamic forces acting on the wing tip device during forwards motion of the aircraft are such that the wing tip device is allowed to rotate about the hinge line away from the ground configuration and towards the flight configuration under the action of said forces; and
wherein the aircraft further comprises an actuator for moving the wing tip device from the ground configuration to the flight configuration, the actuator having a capacity of less than that required for moving the wing tip device in the absence of the aerodynamic forces,
wherein the method comprises the steps of:
i. having the wing tip device in the flight configuration,
ii. starting the landing procedure,
iii. allowing the wing tip device to rotate from the flight configuration towards the ground configuration, at least some of that movement being effected as a result of the decreasing aerodynamic forces on the wing tip device during the landing procedure.

13. The method according to claim 12 wherein the hinge line is orientated at an angle to the flight direction such that the wing tip device presents a larger frontal area when it is in the ground configuration than when it is in the flight configuration.

14. The method according to claim 12 , wherein the step of allowing the wing tip device

Assignees

• Airbus Operations Limted
• Airbus Operations Ltd

Inventors

• Boye Sylvain

Classifications

• Y02T50/14

  Cross-Sectional Technologies · mapped topic

• B64C23/072

  the wing tip airfoil devices being moveable in their entirety · CPC title

• B64C3/56 Primary

  Folding or collapsing to reduce overall dimensions of aircraft · CPC title

• B64U30/12 Primary

  Variable or detachable wings, e.g. wings with adjustable sweep · CPC title

• B64C3/546 Primary

  by foldable elements · CPC title