Inlet nose cowl with a locally thickened fastening portion to enable an uninterrupted airflow surface

1. An aircraft nacelle comprising:

an inlet nose cowl comprising a single piece of sheet metal material between and defining at least a portion of an exterior surface and an interior surface, wherein the exterior surface is exposed to external airflow during flight, and wherein the single piece of sheet metal material forms a locally thickened fastening portion defining at least a portion of the exterior and interior surfaces,

wherein a thickness of the inlet nose cowl between the exterior surface and the interior surface is greater at the fastening portion than at an area surrounding the fastening portion and an area of the interior surface on the locally thickened fastening portion is substantially parallel to an area of the exterior surface on the locally thickened fastening portion, and

wherein a bulkhead is fastened to the substantially parallel area of the interior surface on the locally thickened fastening portion with mechanical fasteners, wherein the mechanical fasteners do not penetrate the exterior surface.

2. The aircraft nacelle of claim 1 , wherein the fastening portion comprises a plurality of holes drilled into the interior surface of the fastening portion, and wherein the holes are configured to receive the mechanical fasteners and do not penetrate the exterior surface.

3. The aircraft nacelle of claim 2 , wherein the fastening portion further comprises a plurality of inserts within the holes, and wherein the inserts are configured to receive the mechanical fasteners.

4. The aircraft nacelle of claim 3 , wherein the inserts are threaded inserts including internal and external threading, the internal threading being configured to receive the mechanical fasteners.

5. The aircraft nacelle of claim 2 , wherein the holes are threaded to receive the mechanical fasteners.

6. The aircraft nacelle of claim 1 , wherein the fastening portion includes scalloped side walls that step or slope down to the area surrounding the fastening portion, the scalloped side walls resulting in the fastening portion having less surface area on the interior surface between each hole than on the interior surface surrounding each hole.

7. The aircraft nacelle of claim 1 , wherein the bulkhead is bonded or welded to the fastening portion in addition to being secured with fasteners.

8. A method of attaching a bulkhead to an inlet nose cowl of an aircraft engine housing component, the inlet nose cowl comprising a single piece of sheet metal material between and defining at least a portion of an exterior surface and an interior surface, wherein the exterior surface is exposed to external airflow during flight, and wherein the single piece of sheet metal material forms a locally thickened fastening portion defining at least a portion of the exterior and interior surfaces, wherein an area of the interior surface on the locally thickened fastening portion is substantially parallel to an area of the exterior surface on the locally thickened fastening portion, the method comprising:

fastening the bulkhead to the substantially parallel area of the interior surface on the locally thickened fastening portion of the interior surface of the inlet nose cowl with mechanical fasteners, wherein a thickness of the inlet nose cowl between the exterior surface and the interior surface is greater at the fastening portion than at an area surrounding the locally thickened fastening portion, and wherein the mechanical fasteners do not penetrate the exterior surface.

9. The method of claim 8 , further comprising:

drilling a plurality of holes into the fastening portion of the interior surface, wherein the holes are configured to receive the mechanical fasteners and do not penetrate the exterior surface.

10. The method of claim 9 , further comprising:

placing a plurality of threaded inserts within the holes, wherein the threaded inserts are configured to receive the mechanical fasteners.