Rotary wing aircraft with two engines and lateral engine fixations
A rotary wing aircraft comprising an upper primary skin that separates an aircraft interior region from an aircraft upper deck. The aircraft upper deck comprises engine compartments, a tail rotor drive shaft arranged therebetween, a firewall arrangement, and a central bracket that is rigidly attached to the upper primary skin below the tail rotor drive shaft 12 c . The central bracket provides central bracket lugs in the engine compartments above the firewall. The engine compartments comprise inboard fixations with inner main mounting brackets adapted for being rigidly attached to engines and to inboard lateral mounts that attach the inner main mounting bracket with the central bracket lugs.
1 . A rotary wing aircraft, with a fuselage that forms an aircraft interior region, the fuselage comprising an upper primary skin that separates the aircraft interior region from an aircraft upper deck arranged above the fuselage, the upper primary skin being mounted on top of a predetermined number of supporting beams; wherein the aircraft upper deck comprises a first engine compartment arranged at a starboard side of the rotary wing aircraft, a second engine compartment arranged at a port side of the rotary wing aircraft, a tail rotor drive shaft that is arranged between the first and second engine compartments, a first firewall that separates the tail rotor drive shaft from the first and second engine compartments, a second firewall that separates the first and second engine compartments from each other, a third firewall that separates the first and second engine compartments from the upper primary skin, and a central bracket rigidly attached to the upper primary skin below the tail rotor drive shaft and providing a first central bracket lug in the first engine compartment above the third firewall and a second central bracket lug in the second engine compartment above the third firewall, the first, second, and third firewalls defining fire proof separations between the first and second engine compartments and the tail rotor drive shaft, between the first and second engine compartments, and between the first and second engine compartments and the upper primary skin, respectively, wherein the first engine compartment comprises a first rear mount, a first outboard fixation, and a first inboard fixation that are adapted for receiving a first aircraft engine, and wherein the second engine compartment comprises a second rear mount, a second outboard fixation, and a second inboard fixation that are adapted for receiving a second aircraft engine, wherein the first inboard fixation comprises a first inner main mounting bracket adapted for being rigidly attached to the first aircraft engine, a first inboard main mount that attaches the first inner main mounting bracket with a first beam web of at least one first beam of the predetermined number of supporting beams, and a first inboard lateral mount that attaches the first inner main mounting bracket with the first central bracket lug, and wherein the second inboard fixation comprises a second inner main mounting bracket adapted for being rigidly attached to the second aircraft engine, a second inboard main mount that attaches the second inner main mounting bracket with a second beam web of at least one second beam of the predetermined number of supporting beams, and a second inboard lateral mount that attaches the second inner main mounting bracket with the second central bracket lug.
2 . The rotary wing aircraft of claim 1 , wherein the central bracket comprises a base that is rigidly attached to the upper primary skin.
3 . The rotary wing aircraft of claim 1 , wherein the central bracket further comprises first and second firewall attachments that are rigidly attached to the first firewall.
4 . The rotary wing aircraft of claim 1 , wherein the central bracket further comprises a central bracket web that extends below the upper primary skin and that is rigidly attached to a third beam web of at least one third beam of the predetermined number of supporting beams.
5 . The rotary wing aircraft of claim 1 , wherein the first inboard lateral mount comprises a first strut that is rotatably mounted to the first central bracket lug via a first spherical bearing, and wherein the second inboard lateral mount comprises a second strut that is rotatably mounted to the second central bracket lug via a second spherical bearing.
6 . The rotary wing aircraft of claim 5 , wherein the first strut is further rotatably mounted to the first inner main mounting bracket via a third spherical bearing, and wherein the second strut is further rotatably mounted to the second inner main mounting bracket via a fourth spherical bearing.
7 . The rotary wing aircraft of claim 6 , wherein a first axis through the first and third spherical bearings and a second axis through the second and fourth spherical bearings intersect at the upper primary skin below the tail rotor drive shaft.
8 . The rotary wing aircraft of claim 7 , wherein the first axis forms a first angle with the upper primary skin, wherein the second axis forms a second angle with the upper primary skin, and wherein the first angle and the second angle have a same value.
9 . The rotary wing aircraft of claim 8 , wherein the first angle is between 25° and 55°.
10 . The rotary wing aircraft of claim 1 , further comprising first and second support ribs that are located between the upper primary skin and the third firewall, respectively, and rigidly attached to the upper primary skin.
11 . The rotary wing aircraft of claim 10 , wherein the central bracket further comprises a first rib attachment that is rigidly attached to the first support rib, and a second rib attachment that is rigidly attached to the second support rib.
12 . The rotary wing aircraft of claim 10 , wherein the first inboard main mount comprises a first inner main mount bracket with a first main mount web that is rigidly attached to the first support rib and the second inboard main mount comprises a second inner main mount bracket with a second main mount web that is rigidly attached to the second support rib.
13 . The rotary wing aircraft of claim 12 , wherein the first inboard main mount comprises a first inner main mount that is rotatably mounted to the first inner main mounting bracket, and wherein the second inboard main mount comprises a second inner main mount that is rotatably mounted to the second inner main mounting bracket.
14 . The rotary wing aircraft of claim 13 , wherein the first inner main mount bracket extends through the third firewall and comprises first and second main mount lugs, and wherein the second inner main mount bracket extends through the third firewall and comprises third and fourth main mount lugs.
15 . The rotary wing aircraft of claim 14 , wherein the first inner main mount is attached to the first and second main mount lugs, and wherein the second inner main mount is attached to the third and fourth main mount lugs.