At Lockheed Georgia flight test, on the C141, (and as well as I recall on the C5A as well) we used a boom mounted far ahead of the nose in undisturbed air. There were vanes on the end of the boom with pivots that kept the probes aligned with the relative wind so that they would read true static and dynamic pressures. Early in the program, we flew with a chase plane that had a calibrated airspeed system to further substantiate the readings in normal flight.