Aerotecnica Sa AC-12 / XZ-1
From the Matra-Cantinieau MC-101 / AC-11 Aerotecnica developed the AC-12 and AC-13, the former powered by a 150hp Lycoming O-320 engine and the latter by a Turbomeca Artouste I gas turbine.
A twin seat single-rotor helicopter, the AC-12 has a full all-metal monocoque fuselage with a large overhead 'spine' encompassing the boom and engine mounted above the cabin. Three-blade rotor with double-articulated blades. Each blade has a solid machined duralumin spar which forms the leading-edge, duralumin ribs and trailing-edge. Space between ribs is filled with a plastic foamed resin compound named Klogecell, with a final overall covering of Fiberglas. Floating hub, with cyclic and collective-pitch changes made through a "spider." Rotor blade area each 0.71sq.m. Rotor disc area 57sq.m. Three-blade anti-torque rotor of similar construction to main rotor. Anti-torque rotor blade area 0.0927sq.m. Anti-torque rotor disc area 2.26sq.m.
The main rotor is driven direct from the engine gear-box (7.28 : 1 ratio) and clutch through a universal joint. The anti-torque rotor is driven through a gear-box (1.4 : 1 ratio) and cardan shaft.
Enclosed cabin seating two side-by-side with dual controls. Entrance door on each side of cabin. Landing gear is skid type. Track of skids 2.0m
Two prototypes were built with Spanish Government funding in Madrid by AISA, with a transmission and reduction gear designed on motor-car principles and built by the ENHASA airscrew company. One 168hp Lycoming O-360-B2A fan-cooled engine mounted above the cabin with direct drive through the gear-box to the main rotor. Fuel tank under seats with capacity of 60 litres. Oil capacity 9 litres. The first of these flew on July 20, 1956.
A production order for 12 was received from the Spanish Government with a military designation of XZ-1 where they served for a relatively short period before being retired.