The Manzolini Libellula was a 1950s Italian co-axial twin-rotor helicopter designed by Ettore Manzolini. "Libellula" is the Italian word for "Dragonfly".

Design and development

Ettore Manzolini established a company in Rome, Italy to develop a helicopter he had designed. The design was the Manzolini Libellula an unusual co-axial helicopter. The co-axial arrangement eliminating the need for an anti-torque rotor allowed the helicopter to have a twin fin arrangement. The Libellula (Registered I-MANZ) first flew on 7 January 1952. An improved version was the single-seat Libellula II which went on to gain Italian certification on 15 October 1962. A three-seater version (the Libellula III) was built and a four-seat Libellula IV was planned but Manzolini stopped development in the late 1960s.

Variants

Libellula

Prototype, one built.

Libellula II

Prototype single-seat version powered by a 75kW (101hp) Walter Minor 4-III engine, one built.

Libellula III

Prototype two-seat version powered by a 104kW (140hp) Walter M 332 engine, one built but not flown.

Libellula IV

Proposed four-seat version powered by a 236kW (317shp) Allison 250-CT18 turboshaft, not built.

Specifications (Libellula II)

Data from Jane's All The World's Aircraft 1965–66^[1]

General characteristics

• Crew: 1
• Length: 4.85 m (15 ft 11 in)
• Height: 3.06 m (10 ft 0 in)
• Empty weight: 498 kg (1,098 lb)
• Max takeoff weight: 650 kg (1,433 lb)
• Powerplant: 1 × Walter Minor 4-III air-cooled 4-cylinder inline engine, 75 kW (101 hp)
• Main rotor diameter: 2 × 9.00 m (29 ft 6 in)
• Main rotor area: 127.2 m² (1,369 sq ft)

Performance

• Maximum speed: 110 km/h (68 mph, 59 kn)
• Cruise speed: 90 km/h (56 mph, 49 kn) (econ cruise)
• Range: 200 km (120 mi, 110 nmi) max fuel, 10 min reserve
• Service ceiling: 2,900 m (9,500 ft)
• Rate of climb: 4.0 m/s (780 ft/min)