CMC vane with detuned platform

A gas turbine engine comprising:

• a compressor section;
• a combustor in fluid communication with the compressor section;
• and
• a turbine section in fluid communication with the combustor, the turbine section having ceramic matrix composite (CMC) vane arc segments each having a platform and an airfoil section extending off of the platform, the platform defining an axially trailing face, an axially leading face that is circumferentially offset from the axially trailing face, and first and second circumferential faces extending from the axially trailing face to the axially leading face, the first and second circumferential faces including chevrons such that a modal excitation response of the platform under cruise conditions is detuned with respect to a natural frequency of the platform differing by a predetermined margin from an external engine operation excitation frequency of turbine blades that rotate past the CMC vane arc segment, wherein the chevrons are aft of a trailing edge of the airfoil section, and first and second circumferential lengths of the platform from the trailing edge of the airfoil section at the axially trailing face to, respectively, the first circumferential face and the second circumferential face are substantially equal.