Three-axis Low Airspeed, Low-Cost Air Data Sensor for Rotorcraft

Current air data systems include standard pitot systems as well as flush port pressure sensors, which suffer from many shortfalls. Installation and calibration must be tailored to each airframe, and airframe modifications may require recalibration of the air data system. This can be costly and time consuming. At high angles of attack the air data is significantly degraded. Rotorcrafts are particularly susceptible to the degradation in capability below 40 knots due to sensitivity issues and the effect of rotor downwash. All of these faults become highly evident during low speed maneuvers, automatic flight control support and weapons delivery. Michigan Aerospace Corporation proposes to determine and demonstrate the performance of a Rotorcraft Optical Air Data System (ROADS) capable of three-axis airspeed measurements at speeds below and above 40 knots. The system will be capable of measurements in longitudinal, vertical and lateral flight with no degradation. The measurement region will be outside of the rotor down wash, minimizing the effect of the downwash on the wind speed measurement. In addition, the proposed system can be produced at a much lower cost than even five years ago due to significant advances at Michigan Aerospace and its laser and detector vendors.