Rotary wing aircraft with an interface frame joining the fuselage tail boom and the tail cone

Patent metadata

Field	Value
Publication number	US-10807697-B2
Application number	US-201715416067-A
Country	US
Kind code	B2
Filing date	Jan 26, 2017
Priority date	Jan 29, 2016
Publication date	Oct 20, 2020
Grant date	Oct 20, 2020

Abstract

A rotary wing aircraft comprising a fuselage tail boom, a tail cone and an interface frame, the interface frame in turn having a connecting structure directly attached to the tail cone by means of a tail cone mechanical connection and a connecting sleeve fitting axially the fuselage tail boom, the connecting sleeve and the fuselage tail boom being directly attached by means of a one boom mechanical connection; the interface frame thereby joining the fuselage tail boom and the tail cone.

First claim

What is claimed is:

1. A rotary wing aircraft comprising:
a fuselage tail boom extending longitudinally along a longitudinal axis, the fuselage tail boom having a tail boom inner surface, which delimits the interior of the fuselage tail boom, and a tail boom outer surface opposite the tail boom inner surface,
a tail cone extending longitudinally along the longitudinal axis,
an interface frame in turn having:
a connecting sleeve extending longitudinally along the longitudinal axis; the connecting sleeve comprising a connecting sleeve inner surface, which delimits the interior of the connecting sleeve, and a connecting sleeve outer surface opposite the connecting sleeve inner surface; the connecting sleeve outer surface overlapping the tail boom inner surface so that the connecting sleeve and the fuselage tail boom fit axially; the connecting sleeve and the fuselage tail boom being directly attached by means of at least one boom mechanical connection, and
a connecting structure directly attached to the tail cone by means of at least one tail cone mechanical connection,

the interface frame, the fuselage tail boom and the tail cone are all made of the same composite material, the interface frame joining the fuselage tail boom and the tail cone; the at least one boom mechanical connection being shear loaded and comprising a boom bushing lining a boom through-hole drilled in the fuselage tail boom and a frame bushing lining a frame through-hole drilled in the interface frame; the frame bushing being provided with a frame flange extending over the connecting sleeve outer surface, and the boom bushing being provided with a boom flange extending over the tail boom inner surface such that the frame flange and the boom flange form a stop for one another resulting in separating the connecting sleeve outer surface from the tail boom inner surface by a circumferential gap.

2. The rotary wing aircraft of claim 1 , wherein the composite material is carbon fiber reinforced plastic.

3. The rotary wing aircraft of claim 1 , wherein the connecting structure comprises a tubular region extending longitudinally along the longitudinal axis, the tubular region having a tubular region inner surface, which delimits the interior of the tubular region, and a tubular region outer surface opposite the tubular region inner surface; wherein the tail cone comprises a tail cone inner surface, which delimits the interior of the tail cone, and a tail cone outer surface opposite the tail cone inner surface; and wherein the tubular region outer surface overlaps the tail cone inner surface, the tubular region being directly attached to the tail cone by means of the at least one tail cone mechanical connection.

4. The rotary wing aircraft of claim 3 , wherein the at least one tail cone mechanical connection is a rivet.

5. The rotary wing aircraft of claim 1 , wherein the at least one boom mechanical connection comprises:
an anchor nut attached to the connecting sleeve inner surface, and
a bolt piercing the connecting sleeve and the fuselage tail boom and locked by the anchor nut, thereby attaching the fuselage tail boom and the connecting sleeve.

6. The rotary wing aircraft of claim 5 , wherein the anchor nut is attached to the connecting sleeve inner surface by means of an anchor nut ring.

7. The rotary wing aircraft of claim 5 ,
the frame bushing lining a frame through-hole is drilled in the connecting sleeve,
the frame bushing having a same inner bushing diameter and a same bushing axis as the boom bushing, thereby forming a bolt passageway thorough which the bolt pierces the connecting sleeve and the fuselage tail boom.

8. A method for assembling a fuselage tail boom and a tail cone of a rotary wing aircraft according to claim 1 , the method comprising the steps of:
(i) providing an interface frame, the interface frame comprising a connecting structure and a connecting sleeve extending longitudinally along the longitudinal axis; the connecting sleeve comprising a connecting sleeve inner surface, which delimits the interior of the connecting sleeve, and a connecting sleeve outer surface opposite the connecting sleeve inner surface;
(ii) providing the connecting sleeve with at least one boom mechanical connection;
(iii) directly attaching the connecting structure to the tail cone by means of at least one tail cone mechanical connection;
(iv) overlapping the connecting sleeve outer surface with the tail boom inner surface, thus axially fitting the connecting sleeve and the fuselage tail boom; and
(v) securing the at least one boom mechanical connection so that the fuselage tail boom and the connecting sleeve are directly attached with the circumferential gap.

9. The method of claim 8 , wherein the at least one boom mechanical connection comprises:
an anchor nut attached to the connecting sleeve inner surface, and
a bolt piercing the connecting sleeve and the fuselage tail boom and locked by the anchor nut, thereby attaching the fuselage tail boom and the connecting sleeve.

10. The method of claim 9 , wherein the at least one boom mechanical connection further comprises:
a boom bushing lining a boom through-hole drilled in the fuselage tail boom,
a frame bushing lining a frame through-hole drilled in the interface frame, and
the frame bushing having a same inner bushing diameter and a same bushing axis as the boom bushing, thereby forming a bolt passageway thorough which the bolt pierces the connecting sleeve and the fuselage tail boom,
wherein the frame bushing is provided with a frame flange extending over the connecting sleeve outer surface and/or wherein the boom bushing is provided with a boom flange extending over the tail boom inner surface, in such a manner that the circumferential gap is defined in between the tail boom inner surface and the connecting sleeve outer surface,
the circumferential gap allowing for the axial fitting of step (iv).

11. The method of claim 8 , wherein the connecting sleeve comprises two mouse holes symmetric to one another with respect to a longitudinal symmetry plane of the connecting sleeve, each one of the two mouse holes giving rise to a joggle in the connecting sleeve perimeter such that, in step (iv), the connecting sleeve inner surface overlaps the tail boom outer surface along a first region of the connecting sleeve perimeter delimited by the two mouse holes, and the connecting sleeve outer surface overlaps the tail boom inner surface along a second region of the connecting sleeve perimeter delimited by the two mouse holes and complementary to the first region of the perimeter.

12. A rotary wing aircraft comprising:
a fuselage tail boom extending longitudinally along a longitudinal axis, the fuselage tail boom having a tail boom inner surface, which delimits the interior of the fuselage tail boom, and a tail boom outer surface opposite the tail boom inner surface,
a tail cone extending longitudinally along the longitudinal axis,
an interface frame having:
a connecting sleeve extending longitudinally along the longitudinal axis; the connecting sleeve comprising a connecting sleeve inner surface, which delimits the interior of the connecting sleeve, and a connecting sleeve outer surface opposite the connecting sleeve inner surface; the connecting sleeve outer surface overlapping the tail boom inner surface so that the connecting sleeve and the fuselage tail boom fit axially; the connecting sleeve and the fuselage tail boom being directly attached by at least one boom mechanical connection, and
a connecting structure directly attached to the tail cone by at least one tail cone mechanical connection,

the interface frame joining the fus

Assignees

• Airbus Helicopters Deutschland GmbH

Inventors

• Probst Stefan
• Walch Philipp
• Nothen Marc
• Buxel Christian
• Schweizer Romed
• Wuerfl Thomas

Classifications

• Y02T50/40

  Weight reduction · CPC title

• B64C2001/0072

  from composite materials · CPC title

• B64C27/04 Primary

  Helicopters · CPC title

• B64C1/26 Primary

  Attaching the wing or tail units or stabilising surfaces · CPC title

• B64F5/10

  Manufacturing or assembling aircraft, e.g. jigs therefor · CPC title