|Nord N.1700 "Norelic"|
The head of the twin-bladed rotor was designed to move parallel to the aircraft's longitudinal plane of symmetry, and also perpendicular to this plane. This arrangement consequently eliminates changes of angle and, of course, the secondary napping brought about by the latter.
Collective pitch and also cyclic pitch were respectively controlled by the radial and the flapping movements of small auxiliary blades set at 90° to the main blades. In this helicopter, the anti-torque device consisted of a fixed-pitch airscrew placed at the end of the tail and blowing backwards on to an assembly of suitably adjusted vanes.
P.Lambermont "Helicopters and Autogyros of the World", 1958
The Societe Nationale de Constructions Aeronautiques du Nord (Nord-Aviation) built its first helicopter prototype in 1947, in which the head of the two-blade rotor moved both parallel to the aircraft's longitudinal plane of symmetry and perpendicular to it.
G.Apostolo "The Illustrated Encyclopedia of Helicopters", 1984
The N.1700 was a two-place aircraft; the rotor had two blades with a stabilizer bar. The engineer Andre Bruel wanted to get rid of the cyclic control, considered too complex. The rotor head was installed on an articulated parallelogram, allowing lateral motions. The lateral control was obtained by relative displacement of the rotor head in relation to the center of gravity.
The 160hp Mathis GR7 engine directly powered a rear axial helix which blew on two flap shutter systems, some horizontal, some vertical, to control pitch and yaw. The aircraft was damaged at first, due to violent vibrations of transmission, induced by brutal clutching. Alter repairing it, they resumed power checks but, in the hands of an inexperienced pilot, it hit an obstacle.
Management decided then to abandon the N.1700 and to turn to a smaller aircraft, the single seat N.1710.
Technical data for N.1700
Engine: 1 x Mathis rated 170hp, rotor diameter: 10m, length: 7m, height: 3m, gross weight: 800kg, empty weight: 510kg, inclined climb: 177m/min, cruising speed: 130km/h, absolute ceiling: 3000m, range: 350km