A free-swiveling vane-type pickup for measuring air flow direction in both the angle-of-attack and angle-of-sideslip directions is described. The device, which is intended to telemeter flow direction from pilotless aircraft, has variable-inductance outputs suitable for use in the 100 to 200 kcps subcarrler frequency range of the NACA FM-AM telemetering system. Preliminary test results indicate that it can also be adapted for use with the audio subcarrier frequencies of the Research and Development Board standard FM-FM telemetering system.nTest results are presented which indicate that the pickup is aero-dynamically stable and has an accuracy, obtained from a bench calibration, of better than O.30 under conditions including acceleration up to 20g in any direction, Mach numbers from 0.5 to 2.8, and dynamic pressures up to at least 65 psi.nEquations and curves which can be used to obtain flow direction at the center of gravity of a maneuvering model are presented.
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