Inlet flow structure for turboprop engine

1. A turboprop engine system for an aircraft comprising:

an engine;

a propeller;

a geartrain coupled to and configured to provide power from the engine to the propeller at a predetermined gear reduction;

a gearbox that houses at least pall of the geartrain, the gearbox including, a gearbox flow structure;

an inlet flow structure that is removably attached to the gearbox, the inlet flow structure and the gearbox flow structure cooperating to delimit an inlet flow passage to the engine, the inlet flow passage having an upstream end with an upstream opening and a downstream end with a downstream opening; and

the upstream opening being cooperatively delimited by both the inlet flow structure and the gearbox flow structure, the downstream opening being cooperatively delimited by the inlet flow structure and the gearbox flow structure, the upstream opening configured to receive an airstream that is directed along the inlet flow passage to the downstream opening and toward the engine.

2. The turboprop engine system of claim 1 , wherein the inlet flow structure includes an edge that extends in a longitudinal direction from the upstream opening to the downstream opening; and

wherein the inlet flow structure is removably attached to the gearbox at the edge.

3. The turboprop engine system of claim 1 , wherein the inlet flow passage extends along a longitudinal axis of the engine system; wherein the upstream opening is arcuate and partially surrounds the axis; and wherein the downstream opening is annular and continuous about the axis.

4. The turboprop engine system of claim 1 , wherein the gearbox includes a support arm that extends at least partially about the inlet flow structure; and

wherein the inlet flow structure is attached to the support arm.

5. The turboprop engine system of claim 4 , wherein the gearbox flow structure and the support arm cooperate to continuously surround the inlet flow structure.

6. The turboprop engine system of claim 4 , further comprising an outer support structure that attaches the engine to the gearbox; and

wherein the outer support structure is attached to the support arm.

7. The turboprop engine system of claim 4 , wherein the support arm and the inlet flow structure are fixedly attached together at a fixed joint; and

further comprising at least one moveable joint that supports the inlet flow structure on the turboprop engine system.

8. The turboprop engine system of claim 7 , wherein the inlet flow passage extends along a flow axis; wherein the fixed joint is disposed between the upstream opening and the downstream opening with respect to the flow axis.

9. The turboprop engine system of claim 8 , wherein the engine includes a rotating group that is supported for rotation about an axis;

wherein the fixed joint is disposed substantially within a first plane;

wherein the upstream end is disposed substantially within a second plane;

wherein the downstream end is disposed substantially within a third plane;

wherein the first plane is disposed at an angle relative to the axis of rotation; and

wherein the second plane and the third plane are substantially normal to the axis of rotation.

10. The turboprop engine system of claim 7 , wherein the inlet flow structure includes an edge that extends in a longitudinal direction from the upstream opening to the downstream opening;

wherein the inlet flow structure is removably attached to the gearbox at the edge; and

wherein the at least one moveable joint includes a first moveable joint at the edge.

11. The turboprop engine system of claim 7 , further comprising a first outer support structure that supports the gearbox and the inlet flow structure at the upstream end;

wherein the at least one moveable joint includes a second moveable joint between the first outer support structure and the inlet flow structure.

12. The turboprop engine system of claim 7 , further comprising an impeller and a compressor shroud that are disposed proximate the downstream end; and

wherein the at least one moveable joint includes a third moveable joint between the downstream end and the compressor shroud.

13. The turboprop engine system of claim 1 , wherein the inlet flow structure includes a first wall, a second wall, and an internal flow passage that is defined between the first wall and the second wall, the internal flow passage configured to receive a de-icing fluid flow.

14. The turboprop engine system of claim 13 , further comprising a partition that extends between the first wall and the second wall; and

wherein the partition separates the internal flow passage into a first flowpath and a second flowpath.

15. The turboprop engine system of claim 13 , wherein the internal flow passage includes an inlet and an outlet;

wherein the internal flow passage extends through the inlet flow structure, from the inlet in an aftward direction and turns forward toward the outlet.

16. The turboprop engine system of claim 1 , wherein the engine includes a rotating group that is supported for rotation about a first axis;

wherein the propeller is supported for rotation about a second axis;

wherein the first axis and the second axis are substantially parallel and spaced apart at a distance.

17. A method of manufacturing a turboprop engine system comprising:

removably attaching an inlet flow structure to a gearbox, the gearbox configured to house at least part of a geartrain that provides power from an engine to a propeller at a predetermined gear reduction, the gearbox including a gearbox flow structure;

the inlet flow structure and the gearbox flow structure, when removably attached, cooperating together to delimit an inlet flow passage to the engine, the inlet flow passage having an upstream end with an upstream opening and a downstream end with a downstream opening, the upstream opening being cooperatively delimited by both the inlet flow structure and the gearbox flow structure, the downstream opening being cooperatively defined by the inlet flow structure and the gearbox flow structure, the upstream opening configured to receive an airstream that is directed along the inlet flow passage to the downstream opening and toward the engine.

18. The method of claim 17 , wherein removably attaching the inlet flow structure to the gearbox includes:

attaching the inlet flow structure to the gearbox at a first joint that is substantially fixed; and

attaching the inlet flow structure to the gearbox at a second joint that is moveable.

19. The method of claim 17 , further comprising attaching the inlet flow structure and the gearbox to another structure at a third joint; and

wherein the third joint is moveable.