Method for forming a composite part of a gas turbine engine

A method for curing a composite part in a gas turbine engine, comprising:

• placing a pre-assembly of the composite part in the gas turbine engine, the pre-assembly having at least a cured first composite material and a second composite material disposed to overlay a portion of the first composite material to define an outer surface of the composite part, the second composite material defining the outer surface of the composite part selected to be curable at a cure temperature generated by heat from operation of the engine in a vicinity of the engine in which the pre-assembly is installed, the first composite material selected to have an operating temperature limit less than the cure temperature of the second composite material;
• and
• operating the engine to cure only the second composite material, the second composite material thermally shielding the first composite material from the heat generated from operation of the engine.

An outer bypass duct wall of a gas turbine engine, comprising:

• a recess in the bypass duct wall along an inner surface thereof having an oil cooler disposed therein, the recess being defined by at least a first layer made of a first composite material, and a second layer made of a second composite material, the second layer disposed to overlay at least part of the first layer between the first layer and the oil cooler to thermally shield the first layer from heat generated by the oil cooler during operation of the gas turbine engine, the second composite material of the second layer having an operating temperature limit being greater than an operating temperature limit of the first composite material of the first layer.