Wheatley John B., Bioletti Carlton. Wind-tunnel tests of a to-foot-diameter Gyroplane rotor

Washington: Langley Memorial Aeronautical Laboratory, 1935. — 10 p.The Jational Advisory Committee for Aeronautic has for several years been studying diITerent types of rotating-wing sy terns because of their pronounced advantages in respect to afe Dight. The advantages are derived mainly from the fact that the air speed of the lifting surfaces of the rotating wing is almost independent of the forward speed of the machine so that large air forces are, under all conditions, available for lift and control. One of the systems studied was the gyroplane, which is of the autorotating type. Opposite blades of the rotor are rigidly connected and the thrusts on each side of the plane of symmetry are equalized by an oscillation, or festhering, of the blade pair about an axis approximately parallel to the span axis. The oscillation can be automatic if the blade center of thrust is behind the feathering axis; a con trolled feathering, effected by a cam arrangem nt in the hub, is usually employed which generates rolling or pitching moments as desired so that conventional elevators and aileron are unnecessary.