A total air temperature probe includes a probe head having an airflow inlet, a main airflow outlet, a main probe head wall extending from the airflow inlet to the main airflow outlet, and a flow separation bend wall positioned between the airflow inlet and the main airflow outlet. The flow separation bend wall is opposite the main probe head wall across a primary flow passage defined through the probe head from the airflow inlet to the main airflow outlet. A flow separation trip feature is defined on an interior surface of the main probe head wall for tripping a boundary layer flow separation in flow in the primary flow passage, e.g., for reduction of deicing heater error.