We claim:
1. An aft engine (200) defining a central axis (220) and configured to
be mounted to an aircraft (10) at an aft end (16) of the aircraft (10), the aft engine
(200) comprising:
a fan (222) rotatable about the central axis (220) and including a plurality of fan blades (228); and
a nacelle (224) surrounding the plurality of fan blades (228) of the fan (222) and defining a bottom portion (248) having a forward end (14), the nacelle (224) defining a curved surface at the forward end (14) of the bottom portion (248) including a reference point where the curved surface defines the smallest radius of curvature (266), the nacelle (224) further defining a normal reference line (268) extending normal from the reference point, the normal reference line (268) defining an angle with the central axis (220) of the aft engine (200) greater than zero.
2. The aft engine (200) as claimed in claim 1, wherein the bottom portion (248) of the nacelle (224) includes an inside surface (254) and an outside surface (256), and wherein the reference point is positioned closer to the outside surface (256) than the inside surface.
3. The aft engine (200) as claimed in claim 1, wherein the forward end (14) of the bottom portion (248) of the nacelle (224) defines a stagnation point (264), and wherein the stagnation point (264) aligns with the reference point on the forward end (14) having the smallest radius of curvature (266) when the aft engine (200) is operated at maximum capacity.

4. The aft engine (200) as claimed in claim 1, wherein the normal reference line (268) defines an angle (270) with the central axis (220) of the aft engine (200) greater than about ten degrees.
5. The aft engine (200) as claimed in claim 1, wherein the normal reference line (268) defines an angle (270) with the central axis (220) of the aft engine (200) greater than about twenty degrees.
6. The aft engine (200) as claimed in claim 1, wherein the nacelle (224) defines an inlet (244), wherein the inlet (244) defined by the nacelle (224) extends substantially 360 degrees around a fuselage (20) of the aircraft (10) when mounted to the fuselage (20) of the aircraft (10).
7. The aft engine (200) as claimed in claim 1, wherein the nacelle (224) surrounds the central axis (220) of the aft engine (200).
8. An aircraft (10) extending between a forward end (14) and an aft end (16) and defining a longitudinal centerline, the aircraft (10) comprising:
a fuselage (20) extending from the forward end (14) of the aircraft (10) towards the aft end (16) of the aircraft (10); and
an aft engine (200) mounted to the fuselage (20) proximate the aft end (16) of the aircraft (10), the aft engine (200) defining a central axis (220) extending parallel to the longitudinal centerline of the aircraft (10), the aft engine (200) comprising
a fan (222) rotatable about the central axis (220) and including a plurality of fan blades (228); and

a nacelle (224) surrounding the plurality of fan blades (228) of the fan (222) and defining a bottom portion (248) having a forward end (14), the nacelle (224) defining a curved surface at the forward end (14) of the bottom portion (248) including a reference point where the curved surface defines the smallest radius of curvature (266), the nacelle (224) further defining a normal reference line (268) extending normal from the reference point, the normal reference line (268) defining an angle with the central axis (220) of the aft engine (200) greater than zero.
9. The aircraft (10) as claimed in claim 8, wherein the aircraft (10) defines a mean line (18) extending from the forward end (14) to the aft end (16), and wherein the nacelle (224) extends substantially 360 degrees around the mean line (18) of the aircraft (10).
10. The aircraft (10) as claimed in claim 8, wherein the bottom portion (248) of the nacelle (224) further defines a chord line (250), and wherein the normal reference line (268) defines an angle (272) with the chord line (250) greater than zero.