CMC trailing edge 3D weaved cross brace

A method of forming a ceramic matrix composite airfoil, the method comprising:

• forming a fibrous ceramic preform by:
• laying up a plurality of plies to form a hollow core cavity;
• overwrapping the plurality of plies of the core cavity with a first overwrap layer;
• weaving together a tows of first free portion and tows of a second free portion of the first overwrap layer to form a cross brace, the cross brace having an “X” shaped cross-sectional geometry;
• overwrapping the plurality of plies of the core cavity and the first overwrap layer with a second overwrap layer;
• and consolidating the first free portion and the second free portion of the first overwrap layer and a third free portion and a fourth free portion of the second overwrap layer to form a trailing edge, wherein the cross brace is disposed in a trailing edge void of the fibrous preform, partially defining a plurality of sub-cavities of the trailing edge void;
• and wherein the hollow core cavity and a first of the plurality of sub-cavities are separated from each other by a common wall comprised of a subset of the plurality of plies.