Rotary wing aircraft with a firewall arrangement

1. A rotary wing aircraft comprising:

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;

a firewall arrangement comprising a front firewall;

wherein the aircraft upper deck comprises an engine accommodating region with the firewall arrangement arranged therein, the engine accommodating region comprising an engine accommodating compartment bounded in part by the firewall arrangement, the engine accommodating region accommodating at least one aircraft engine within the engine accommodating compartment such that the firewall arrangement defines a fire proof separation and a flammable fluids tightness at least between the at least one aircraft engine and the aircraft interior region;

the firewall arrangement comprises within the engine accommodating compartment at least one gasket, the at least one gasket being removably attached within the engine accommodating compartment to the front firewall for tightening pass-through, through the front firewall, of a torque tube that connects the at least one aircraft engine to a main gear box of the rotary wing aircraft that is outside of the engine accommodating compartment; and

the at least one gasket comprises at least two fire proof shells that are removably attached to each other to form a tube-shaped structure for accommodating therein the torque tube, and a ring-shaped flexible fire proof bellows which forms a cuff-like structure for accommodating therein the torque tube and that is removably mounted to the at least two fire proof shells and configured to compensate movements of the torque tube relative to the firewall arrangement, the ring-shaped flexible fire proof bellows being attached within the engine accommodating compartment to an associated counterpart of the at least one aircraft engine by mushroom head pins.

2. The rotary wing aircraft of claim 1 wherein the at least one gasket forms a flammable fluids barrier and is configured to provide a fire proof segregation and thermal isolation of the torque tube from the at least one aircraft engine.

3. The rotary wing aircraft of claim 1 wherein at least one of the at least two fire proof shells comprises titanium.

4. The rotary wing aircraft of claim 3 wherein the at least one of the at least two fire proof shells is a semi-cylindrical titanium shell.

5. The rotary wing aircraft of claim 1 wherein the ring-shaped flexible fire proof bellows comprises a fiber reinforced fabric.

6. The rotary wing aircraft of claim 5 wherein the fiber reinforced fabric comprises at least one silicone coated glass fiber fabric layer.

7. The rotary wing aircraft of claim 5 wherein the fiber reinforced fabric comprises at least one silicate glass fiber fabric layer.

8. The rotary wing aircraft of claim 1 wherein the ring-shaped flexible fire proof bellows comprises at least two metal rings to form a ring-shaped bellows structure.

9. The rotary wing aircraft of claim 8 wherein at least one of the at least two metal rings is removably mounted to the at least two fire proof shells via associated fasteners.

10. The rotary wing aircraft of claim 8 wherein the at least two metal rings are stainless steel metal rings.

11. The rotary wing aircraft of claim 1 wherein the at least two fire proof shells are removably attached to each other by means of associated shell clamps.

12. The rotary wing aircraft of claim 1 wherein the at least one gasket is removably attached to the front firewall of the firewall arrangement by means of associated quick release fasteners.

13. The rotary wing aircraft of claim 12 wherein the firewall arrangement further comprises at least a rear firewall and a mid firewall, the front firewall and the rear firewall are interconnected via the mid firewall.

14. The rotary wing aircraft of claim 1 wherein the at least two fire proof shells overlap the ring-shaped flexible fire proof bellows at least partly.

15. The rotary wing aircraft of claim 1 wherein each of the at least two fire proof shells has a partial tubular circumference, and the partial tubular circumferences of the at least two fire proof shells removably attached to each other all together form a complete tubular circumference of the tube-shaped structure.

16. The rotary wing aircraft of claim 15 wherein the ring-shaped flexible fire proof bellows comprises at least two metal rings and a fiber reinforced fabric, the fiber reinforced fabric connecting together the at least two metal rings, and the at least two metal rings otherwise being disconnected from one another.

17. The rotary wing aircraft of claim 16 wherein a first one of the at least two metal rings is removably mounted to the at least two fire proof shells for the ring-shaped flexible fire proof bellows to be removably mounted to the at least two fire proof shells, and a second one of the at least two metal rings is attached to the associated counterpart of the at least one aircraft engine by the mushroom head pins for the ring-shaped flexible fire proof bellows to be attached within the engine accommodating compartment to the associated counterpart of the at least one aircraft engine.

18. The rotary wing aircraft of claim 17 wherein the at least two fire proof shells at least partly overlap the first one of the at least two metal rings removably mounted to the at least two fire proof shells.

19. The rotary wing aircraft of claim 16 wherein the fiber reinforced fabric comprises a silicone coated glass fiber fabric layer and/or a silicate glass fiber fabric layer.

20. The rotary wing aircraft of claim 1 wherein the ring-shaped flexible fire proof bellows comprises at least two metal rings and a fabric layer, the fabric layer connecting together the at least two metal rings, and the at least two metal rings otherwise being disconnected from one another.