Abstract: An airfoil for a gas turbine engine, the airfoil includes a plurality of cooling air passages to supply cooling air to an external surface of the airfoil, the cooled surface of the airfoil having a critical temperature in which any cooled surface of the airfoil should not exceed, the cooling air passages having a coating applied within the passages, the coating being made of a material that has an oxidizing property such that the material oxidizes away and opens the passage to more flow when exposed to a temperature above the critical temperature. When the airfoil surface is not properly cooled by a flow passing through the passage, the material oxidizes away until the size of the passage increases to allow for the proper amount of cooling air to flow to cool the airfoil. Each passage is located in a different part of the airfoil that requires more or less cooling flow, and each passage will oxidize until the size of the passage is large enough to allow for the proper amount of cooling flow.