A cooling system for a component of a gas turbine engine includes a first airflow passage configured to direct a first airflow to a mixing chamber and a second airflow passage to configured direct a second airflow to the mixing chamber, the second airflow having a higher temperature than the first airflow, and a cooling airflow passage to direct a cooling airflow from the mixing chamber to the component, the cooling airflow comprising the first airflow and the second airflow. The airflow passages are configured and sized to allow an amount of cooling airflow for unrestricted engine operation. When the first airflow passage is disabled, the second airflow passage and cooling airflow passage are configured and sized to allow an amount of cooling airflow which is adequate to permit continued safe engine operation restricted to within only a portion of its normal parameters and operating envelope.