In-Air Trapped Static Method for Aircraft Pressure Altitude and Airspeed

Accurate aircraft airspeed measurement has always been crucial for analyzing, testing, and certifying aircraft performance, handling qualities, loads, flutter, and structural integrity. Indicated or calibrated airspeed, determined by impact pressure, relies on total pressure from the pitot tube and static pressure from the static port(s), both susceptible to distortion by local flow near the pressure sensors. Various methods used for measuring static pressure have either been expensive to operate or suffered from degraded accuracy and efficiency. This paper introduces the In-Air Trapped Static (IATS) method for computing accurate static pressure and airspeed from a pressure altitude profile anchored at identified trapped static points. The pressure altitude profile is constructed using kinematically corrected geometric altitude and a local temperature profile extracted from recorded flight data. The author hopes that this method, with its significantly enhanced airspeed accuracy, will promote consistency in aircraft development and certification for both manufacturers and regulatory agencies, thereby improving the safety of aircraft operation.