TY - JOUR AB - THE Cierva autogyro is a windmill of low pitch whose plane is inclined at a small angle to the relative wind; this windmill takes the place of the wing system of an ordinary aeroplane. The windmill rotates on a ball bearing, and each blade is hinged on a ball bearing, whose axis lies in the plane of rotation so that the blades are free to flap in a direction normal to this plane. In flight the windmill rotates freely under the influence of the relative wind caused by the forward or downward motion of the machine, while the blades are prevented from departing far from the plane of rotation by centrifugal force, but execute a slight flapping oscillation relative to the plane of rotation under the influence of the unsymmetrical aerodynamic forces. VL - 1 IS - 1 SN - 0002-2667 DO - 10.1108/eb029095 UR - https://doi.org/10.1108/eb029095 PY - 1929 Y1 - 1929/01/01 TI - Efficiency of the Autogyro: Summary of Results of Exhaustive Tests Carried Out at the National Physical Laboratory T2 - Aircraft Engineering and Aerospace Technology PB - MCB UP Ltd SP - 23 EP - 24 Y2 - 2024/04/24 ER -