A turbine engine includes a turbine, a compressor for compressing air and a combustor for receiving the compressed air through an inlet passage and operable to burn fuel therewith to deliver hot exhaust gas to the turbine. Also included is a wheel space defined proximate to the combustor. Further included is a cooling air passage extending between the compressor and the wheel space. Yet further included is a valve assembly having a valve member disposed in the cooling air passage and operable to admit a cooling air to the wheel space in response to a condition therein.