Aircraft firewall

1. An aircraft firewall ( 12 ) separating first and second compartments ( 1 and 2 ) of said aircraft, said first compartment ( 1 ) containing a plurality of elements, the firewall ( 12 ) being provided with a first wall ( 3 ) inserted in a structure ( 5 ) of the aircraft and having a first surface ( 3 ′) facing said first compartment ( 1 ), and is provided with regulator means ( 4 , 13 ) for maintaining a maximum temperature of said first surface ( 3 ′) of the first wall ( 3 ) at a predetermined temperature value lower than a self-combustion temperature of said elements,

wherein said aircraft is a rotorcraft, a power transmission gearbox being arranged in said first compartment ( 1 ), and a turboshaft engine ( 9 ) being disposed in said second compartment ( 2 ).

2. The firewall according to claim 1 , wherein said maximum temperature lies in the range 300° C. to 310° C., on a continuous basis.

3. The firewall according to claim 1 , wherein said regulator means include thermal protection for said first wall ( 3 ).

4. The firewall according to claim 1 , wherein said regulator means include a second wall ( 4 ) inserted in the structure ( 5 ) of the aircraft so that said first and second walls ( 3 and 4 ) are respectively beside the first and second compartments ( 1 and 2 ).

5. The firewall according to claim 4 , wherein said regulator means include thermal protection for said second wall ( 2 ).

6. An aircraft firewall ( 12 ) separating first and second compartments ( 1 and 2 ) of said aircraft, said first compartment ( 1 ) containing a plurality of elements, the firewall ( 12 ) being provided with a first wall ( 3 ) inserted in a structure ( 5 ) of the aircraft and having a first surface ( 3 ′) facing said first compartment ( 1 ), and is provided with a regulator ( 4 , 13 ) for maintaining a maximum temperature of said first surface ( 3 ′) of the first wall ( 3 ) at a predetermined temperature value lower than a self-combustion temperature of said elements,

wherein said regulator comprises a second wall ( 4 ) inserted in the structure ( 5 ) of the aircraft in such a manner that said first and second walls ( 3 and 4 ) are respectively beside the first and second compartments ( 1 and 2 ), said first and second walls ( 3 and 4 ) of the firewall defining an internal space ( 8 ) for passing a stream of cool air (F), said stream of cool air (F) penetrating into said internal space ( 8 ) via at least one inlet orifice ( 6 ) and exiting via at least one outlet orifice ( 7 ) so that said firewall ( 12 ) is ventilated.

7. The firewall according to claim 6 , wherein said stream (F) of cool air comes from the surrounding air situated outside said aircraft.

8. The firewall according to claim 6 , wherein said inlet orifice ( 6 ) is made in the structure ( 5 ) of the aircraft between said first and second walls ( 3 and 4 ) of the firewall ( 12 ).

9. The firewall according to claim 6 , wherein said outlet orifice ( 7 ) is made in one of the first and second walls ( 3 and 4 ) of said firewall.

10. The firewall according to claim 6 , wherein said second compartment ( 2 ) contains an engine ( 9 ) and said outlet orifice ( 7 ) is made through said second wall ( 4 ) situated beside the second compartment ( 2 ).

11. The firewall according to claim 6 , wherein said stream (F) of cool air flows in said internal space ( 8 ) of said firewall ( 12 ) by being sucked into suction means of the regulator means.

12. The firewall according to claim 11 , said suction means comprising a duct ( 13 ) connecting said outlet orifice ( 7 ) to a gas exhaust nozzle ( 10 ) of an engine ( 9 ) of the aircraft, the exhaust stream (F′) of said gas creating a depression suitable for sucking in said stream (F) of fresh air.

13. The firewall according to claim 12 , wherein said nozzle ( 10 ) has a bend, and said duct opens out into a bend ( 10 ′) of the nozzle ( 10 ).

14. The firewall according to claim 12 , wherein said duct ( 13 ) includes a check valve ( 14 ) preventing fluids from flowing from the exhaust nozzle towards the firewall.