The helicopters designed by Jean Cantinieau were distinguished by having an engine positioned in front and immediately below the main rotor drive shaft, above the cockpit.

This was also an open steel tube design, more complex particularly in the tail boom, though the undercarriage was reduced to simple skids 1.8 m (71 in) apart.

[2] It had a 78 kW (105 hp) Hirth HM-504 engine,[3] enclosed in a long, smooth nosed but partially open sided cowling, driving the oscillating rotor hub via a 41:6 reduction gearbox, clutch and Paulstra universal joint.

[3] In 1953[4] Cantinieau was appointed as director of the Spanish company Aerotécnica's new helicopter division, which also acquired the rights to the MC-101 from Matra.

[5] The Hirth engine was replaced with a more powerful 112 kW (150 hp) air-cooled flat four Lycoming O-320, in order to cope better with Madrid's hot and high atmosphere, and the helicopter was renamed the Aerotécnica AC-11.