Fairing for folding wing tip

Patent metadata

Field	Value
Publication number	US-11738854-B2
Application number	US-201917296205-A
Country	US
Kind code	B2
Filing date	Dec 2, 2019
Priority date	Jan 30, 2019
Publication date	Aug 29, 2023
Grant date	Aug 29, 2023

Abstract

An aircraft with wing tip devices, for example, folding wing tips, is disclosed. The folding wing tip may have a flight configuration for use during flight, and a ground configuration for use in ground-based operations. The ground configuration creates a shorter wing span than when the aircraft is in the flight configuration. A hinge arrangement protrudes beyond an outer surface of the fixed wing and wing tip device. In order to reduce the aerodynamic effect of the protruding hinge a fairing may be provided. In the flight configuration the fairing comprises a rear portion with a concave surface, such that the fairing acts as a lift-generating surface when the aircraft is in flight.

First claim

The invention claimed is:

1. An aircraft comprising an aircraft wing, the aircraft wing comprising a fixed wing and a wing tip device at the tip thereof, wherein the wing tip device is configurable 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 moved away from the flight configuration such that the span of the aircraft wing is reduced,
the aircraft wing further comprising
a hinge arrangement connecting the fixed wing and the wing tip device,
wherein the hinge arrangement protrudes beyond an outer surface of the fixed wing and wing tip device, and
a fairing covering the protruding portion of the hinge,

wherein the fairing comprises a rear portion with a concave surface, the concave surface creating a lift-generating portion of the fairing during flight, and
wherein the fairing is located only on a lower surface of the aircraft wing.

2. An aircraft as claimed in claim 1 , wherein the rear portion extends beyond the trailing edge of the fixed wing and wing tip device.

3. An aircraft as claimed in claim 1 , wherein the rear portion of the fairing comprises a trailing edge which is parallel in direction to the trailing edge of the fixed wing and/or wing tip device.

4. An aircraft as claimed in claim 1 , wherein the rear portion tapers in span-wise width as it extends away from the trailing edge of the fixed wing and wing tip device.

5. An aircraft as claimed in claim 1 , wherein the rear portion comprises a point of inflection in the line of flight direction, at which point the cross-sectional profile of the rear portion changes from a convex profile to a concave profile, as the rear portion extends in a rearward direction.

6. An aircraft as claimed in claim 5 , wherein the point of inflection is located in a region between 100% to 60% of the chord length of the wing, taken in a line of flight direction and moving from the leading edge (0%) to trailing edge (100%) of the wing.

7. An aircraft as claimed in claim 1 , wherein as the fairing extends in a span-wise direction, the rear portion of the fairing comprises a surface which extends tangentially from the wing skin of the fixed wing in a concave direction, undergoes a point of inflection to extend in a convex direction, and undergoes a further point of inflection such that it extends in a concave direction to a point where it is tangential to the wing skin of the wing tip device.

8. An aircraft as claimed in claim 1 , wherein the fairing comprises a front portion blended into and extending rearwardly from the leading edge of the fixed wing and the wing tip device when the wing tip device is in the flight configuration.

9. An aircraft as claimed in claim 8 , wherein the front portion of the fairing meets the leading edge of the fixed wing and wing tip device in a tangential direction.

10. An aircraft as claimed in claim 8 , wherein the front portion of the fairing meets the leading edge of the fixed wing and wing tip device, such that when viewed in a line of flight cross-section, there is no discontinuity between the fairing and the leading edge of the fixed wing and wing tip device.

11. An aircraft as claimed in claim 8 , wherein as the fairing extends in a span-wise direction across the wing, the fairing comprises a concave surface extending from the wing skin of the fixed wing, the concave surface starting in a direction tangential to the wing skin, a point of inflection in a span-wise direction, at which point the surface becomes a convex surface, such that the convex surface extends over maximum protrusion of the hinge arrangement, an additional point of inflection, at which point the surface becomes a concave surface, such that the concave surface meets the wing tip device wing skin in a tangential direction.

12. An aircraft as claimed in claim 1 , wherein the fairing is symmetrical about a line of flight axis, the axis located at the point of greatest depth of the fairing.

13. An aircraft as claimed in claim 1 , wherein the edges of the fairing, where the fairing blends into the fixed wing or wing tip device, the edges extend in a line of flight direction.

14. An aircraft as claimed in claim 1 , wherein the fairing comprises a consistent span-wise width across at least 70% of the fairing.

15. An aircraft as claimed in claim 1 , wherein the hinge arrangement extends in a line of flight direction.

16. An aircraft as claimed in claim 15 , wherein the hinge arrangement extends in a line of flight direction such that it extends over at least 60% of the aircraft wing in a line flight direction.

17. An aircraft wing comprising a fixed wing and a wing tip device at the tip thereof, wherein the wing tip device is configurable 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 moved away from the flight configuration such that the span of the aircraft wing is reduced,
the aircraft wing further comprising
a hinge arrangement connecting the fixed wing and the wing tip device,
wherein the hinge arrangement protrudes beyond an outer surface of the fixed wing and wing tip device, and a fairing covering the protruding portion of the hinge,
wherein in the flight configuration the fairing comprises a rear portion with a concave surface, the surface creating a lift-generating portion of the fairing during flight, and
wherein the fairing is located only on a lower surface of the aircraft wing.

18. An aircraft comprising an aerodynamic structure, a protruding structure and a fairing covering the protruding structure, wherein the fairing is blended into the aerodynamic structure in a line of flight direction and in a span-wise direction, wherein the fairing is located only on a lower surface of the aircraft wing, such that there are no discontinuities at the transition between the surface of the aerodynamic structure and the fairing.

19. An aircraft comprising an aerodynamic structure according to claim 18 , wherein the fairing meets the surface of the aerodynamic structure along an interface, and wherein the fairing is shaped such that the surface of the fairing is tangential to the surface of the aerodynamic structure along the interface.

20. A fairing for an aircraft, the fairing comprising an interface surface for interfacing with the aircraft in a tangential direction, and an aerodynamic surface, the fairing further comprising a seamless transition from the interface surface to the aerodynamic surface, and wherein the fairing is located only on a lower surface of the aircraft wing.

21. A fairing as claimed in claim 20 , the fairing comprising a longitudinal axis corresponding to the line of flight direction when mounted on an aircraft, wherein the cross-sectional profile of the fairing taken perpendicular to the longitudinal axis comprises a bell-shaped curve.

22. A fairing as claimed in claim 21 , wherein the aerodynamic surface comprises a concave surface.

Assignees

• Airbus Operations Ltd

Inventors

• Lowry Richard
• Lyons Neil John

Classifications

• B64C3/56 Primary

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

• B64C7/00 Primary

  Structures or fairings not otherwise provided for · CPC title

• B64C3/546

  by foldable elements · CPC title

• B64C21/08

  adjustable · CPC title

• B64C23/072 Primary

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