Fixed Wing Gyroplanes: The Efficiency, Performance and Stability of a Combination of Fixed and Rotating Surfaces

THE advantages and disadvantages of the fixed wing for gyroplanes are examined. On the simplest assumptions an expression for the percentage load taken by the fixed wing of a gyroplane is derived. The values so arrived at are compared with those found by experiment and the discrepancy between the two is explained in terms of the increased downwash at the centre of the disc of the gyroplane. It is shown that as much as 50 per cent of the weight of the aircraft can be taken by the wing at top speed with moderate wing area and the most suitable setting. The advantages of an adjustable wing from the point of view of rotor speed control are pointed oat. The Lift/Drag of the combination is raised by 2 over the L/D of the rotor alone. The stability of gyroplanes is discussed.