The Aérospatiale SA 321 Super Frelo was designed as a large, heavy-lift single-rotor helicopter, furnished with a relatively atypical three-engine configuration

Produced by French aerospace manufacturer Sud Aviation, the Aérospatiale SA 321 Super Frelon was a more powerful development of the original SE.3200 Frelon, which had failed to enter production. It was considered the most powerful helicopter to be built in Europe at one point, as well as being the world’s fastest helicopter.

The SA 321 Super Frelon with triple-engine, medium-lift design, became the largest helicopter designed, and built in Europe in greatest numbers when it entered service with the French Navy in 1966. The Super Frelon was most heavily used by naval air arms, such as the French Navy and the People’s Liberation Army Naval Air Force. Other operators were Argentina, Greece, Iraq, Israel, Libya, South Africa and Zaire.

The Aérospatiale SA 321 Super Frelo was designed as a large, heavy-lift single-rotor helicopter, furnished with a relatively atypical three-engine configuration. It is powered by Turboméca Turmo IIIC turboshaft engines, set on top of the fuselage, a pair of turbines positioned side by side at the front and one located aft of the main rotor.

The naval anti-submarine and anti-ship variants are usually equipped with navigation and search radar, and a 50-metre rescue cable. They are most often fitted with a 20 mm cannon, countermeasures, night vision, a laser designator and a Personal Locator System. The Super Frelon can also be fitted for inflight refueling.
The helicopter featured a large, slab-sided fuselage with the heavily-glazed cockpit at the nose, and the passenger cabin lined with rectangular windows. A wheeled tricycle undercarriage was used for ground-running. Over the top of the fuselage was seated the triple-engine configuration, and these drove the multi-bladed main rotor atop the vehicle, as well as a five-bladed tail rotor aft.

At the rear of the cabin is a tapered section of simple semi-monocoque construction, which is closed by a robust hinged rear loading ramp, which serves as the main entrance for bulky loads or equipment. The loading ramp is jettisonable in emergency situations. Additionally, there is a sliding door located on the forward starboard side, while a small hinged emergency door is set on the aft port side.

SA 321 Super Frelon has a length of 23 m, a length of 19.40 m, a height of 6.66 m, an empty weight of 6.86 tons, and a maximum take-off weight of 13 tons. The maximum speed is 249 km/h, the range is 1,020 km, the service ceiling is 3,150 m, and the rate of climb is 6.66 m/s.

Source: https://military-wiki.com/sa-321-super-frelon-the-most-powerful-helicopter-ever-built-in-europe/