Device for feeding combustion air to an engine of an aircraft

1. A device for feeding combustion air to an engine disposed in an interior of an aircraft comprising:

a primary air inlet duct extending between an exterior surface of the aircraft and the engine, wherein the air inlet duct extends from air inlets disposed in a first region of the exterior surface and provides combustion air to the engine;

at least two further inlet ducts extending between a second and third region of the exterior surface and the engine, so as to provide a three-way combustion air supply, with each of the at least two further inlet ducts having an end inlet-cover filter element;

wherein the second and third regions are on opposite longitudinal sides of the exterior surface, the longitudinal sides extending between fore and aft of the aircraft; and

a control device configured to switch the combustion air supply to the engine from either or both of the at least two further inlet ducts when a blockage occurs in the primary air inlet duct.

2. The device as recited in claim 1 , further comprising at least one inflow flap corresponding to the at least one air inlet duct, and wherein the control device is configured to open the at least one inflow flap.

3. The device as recited in claim 2 , wherein the at least one inflow flap is movable along a rail guide using a hydraulic cylinder or an electric linear drive between an open position and a closed position.

4. The device as recited in claim 2 , wherein the at least one inflow flap is disposed so as to be rotatable on a hinge.

5. The device as recited in claim 1 , further comprising a pressure sensor connected to the control device configured to detect the blockage of the air inlets, and wherein the control device contains a defined pressure threshold value.

6. The device as recited in claim 1 , wherein the aircraft includes a second engine, and wherein one of the at least two further air inlet ducts supplies combustion air to the first engine and another of the at least two further inlet ducts supplies combustion air to the second engine and wherein the second region is at the top of the exterior surface of the aircraft.

7. The device as recited in claim 6 , further comprising a firewall affixed to the engine and wherein the at least one air inlet duct for each engine is detachably attached to the firewall.

8. The device as recited in claim 6 , wherein the at least one air inlet duct is comprised of a high-temperature-resistant BMI (bismaleimide) material.

9. The device as recited in claim 6 , wherein the inlet-cover filter element includes a closed attachment frame enclosing a flat filter body, the flat filter body including a protective grill at least externally.

10. The device as recited in claim 1 , wherein the at least one further air inlet duct includes at least one further inlet-cover filter element.

11. The device as recited in claim 1 , wherein each air inlet includes an additional inlet-cover filter element.

12. A helicopter comprising:

a rotor-driving engine; and

a device for feeding combustion air to the engine, the device including a primary combustion air inlet duct extending between an exterior surface of the aircraft and the engine, wherein the air inlet duct extends from air inlets disposed in a first region of the exterior surface;

at least two further air inlet ducts extending between a second and third region of the exterior surface and the engine, so as to provide a three-way airstream supply; and

a control device configured to switch the combustion air supply to the engine from the primary air inlet duct to either or both of the at least two further air inlet ducts when a blockage occurs in the primary air inlet duct.