Surface cooler and method of forming

A surface cooler assembly configured to be operably coupled to an aircraft fan casing, the surface cooler assembly comprising:

• a surface cooler including a body having a first surface configured to confront the aircraft fan casing and a second surface opposite the first surface, the surface cooler comprising:
• a set of fluid passages internal to the body;
• a set of fins extending from a first portion of the second surface of the body;
• a return manifold portion unitarily formed with the body and comprising a return interior passage fluidly coupling a first fluid passage of the set of fluid passages to a second fluid passage of the set of fluid passages and redirecting a fluid flow from the first fluid passage to the second fluid passage by way of the return interior passage;
• and
• an attachment boss unitarily formed with the body and configured to couple the body to the aircraft fan casing;
• wherein the return interior passage overlies a second portion of the second surface of the body which is devoid of fins.

A method of forming a surface cooler, the method comprising:

• forming a curved base body defining a first exterior surface and a second exterior surface opposite the first exterior surface, and the curved base body having a first fluid passage and a second fluid passage both internal to the curved base body, wherein the first exterior surface is configured to be operably coupled to a fan casing of an aircraft engine;
• forming fins extending from a portion of the second exterior surface of the curved base body;
• forming a manifold unitarily with the curved base body having an interior passage fluidly coupled to at least the first fluid passage, with the interior passage spaced from the fins, wherein the interior passage of the manifold comprises:
• a first section overlying a portion of the second exterior surface that is devoid of fins, and providing flow redirection from the first fluid passage to the second fluid passage;
• or
• a second section, different from the first section and extending in a radial direction with respect to the curved base body, providing an inlet to the at least the first fluid passage;
• and
• forming an attachment boss unitarily with the curved base body at the manifold, with the attachment boss configured to couple the curved base body to the fan casing.