Embodiments of a cover plate and material blank for forming the cover plate may include features and characteristics to accommodate tolerance issues in a turbine vane assembly. In one embodiment, the cover plate is formed from a material blank configured to provide the cover plate with a flexible flange area that can be secured to the turbine vane assembly. The flange area may have a range of motion that may be responsive to an installation force, which effectively modifies the configuration of the cover plate to such degree as to seal the cover plate to the turbine vane assembly.