The Alouette III has its origins with an earlier helicopter design by French aircraft manufacturer Sud-Est, the SE 3120 Alouette, which, while breaking several helicopter speed and distance records in July 1953, was deemed to have been too complex to be realistic commercial product. Having received financial backing from the French government, which had taken an official interest in the venture, the earlier design was used as a starting point for a new rotorcraft that would harness the newly developed turboshaft engine; only a few years prior, Joseph Szydlowski, the founder of Turbomeca, had successfully managed to develop the Artouste, a 260 hp (190 kW) single shaft turbine engine derived from his Orédon turbine engine. This engine was combined with the revised design to quickly produce a new helicopter, initially known as the SE 3130 Alouette II.
SE 3130 Alouette II
During April 1956, the first production Alouette II was completed, becoming the first production turbine-powered helicopter in the world. The innovative light helicopter, soon broke several world records and became a commercial success. As a result of the huge demand for the Alouette II, manufacturer Aérospatiale took a great interest in the development of derivatives, as well as the more general ambition of embarking on further advancement in the field of rotorcraft.
In accordance with these goals, the company decided to commit itself to a new development programme with the aim of developing a more powerful helicopter that would be capable of accommodating up to 7 seats or a pair of stretchers.
The design team was managed by French aerospace engineer René Mouille. The design produced, which was initially designated as the SE 3160, featured several improvements over the Alouette II; efforts were made to provide for a higher level of external visibility for the pilot as well as for greater aerodynamic efficiency via the adoption of a highly streamlined exterior.
On 28 February 1959, the first prototype SE 3160 performed its maiden flight, piloted by French aviator Jean Boulet. Shortly thereafter, the SE 3160 would become more commonly known as the Alouette III. During its flight test programme, the prototype demonstrated its high altitude capabilities on several occasions; in June 1959, it landed at an altitude of over 4,000 meters in the Mont Blanc mountain range and, during October 1960, it was able to achieve the same feat at an altitude in excess of 6,000 meters in the Himalayas. During these attempts, it was flown by Jean Boulet, who was accompanied by a pair of passengers and 250 kg of equipment.
During 1961, the initial model of the type, designated as the SA 316A (SE 3160), entered serial production. On 15 December 1961, the Alouette III received its airworthiness certificate, clearing it to enter operational service. Despite an order placed by the French Army for an initial batch of 50 Alouette IIIs during June 1961, the first two customers of the rotorcraft were in fact export sales, having been sold outside of France.
The Alouette III was specifically designed to fly at high altitudes, as such, it quickly earned a reputation for its favourable characteristics during rescue operations. According to its manufacturer, it was the first helicopter to present an effective multi-mission capability and performance to match with its diverse mission range in both civil and military circles.
The SA 316A model continued to be produced until 1968, when it was replaced by the refined SA 316B model. A key feature of the rotorcraft is its gas turbine engine; while the original variant had been powered by the same Artouste engine of the Alouette II, it was substantially more powerful, being originally rated to produce 880 horsepower, but intentionally de-rated to generate 550 horsepower in service. The more powerful Turbomeca Astazou engine would be adopted on the later models; on 10 July 1967, the first Alouette III to be powered by the Astazou engine performed its first flight.
During 1979, the last and 1,437th Alouette III departed from the company's assembly line in Marignane, France, after which the main production line was closed down as a consequence of diminishing demand for the type. During 1985, the final Alouette III was delivered. This was not the end of all production activity however.
Over 500 Alouette IIIs are recorded as having been manufactured under licence abroad in several countries, such as Romania, India, and Switzerland. Hindustan Aeronautics Limited (HAL) obtained a license to construct the Alouette III, which was known locally as the HAL Chetak, at their own production facilities in India. In excess of 300 units were built by HAL; the company has continued to independently update and indigence the helicopter over the decades. A modernised variant of the Chetak has remained production, though at a diminished volume, into the 21st century. Various versions of the Alouette III were also either license-built or otherwise assembled by IAR in Romania (as the IAR 316), F+W Emmen (de) in Switzerland, and by Fokker and Lichtwerk in the Netherlands.
The Alouette III served for over 44 years in the South African Air Force (SAAF). During its service life, the fleet was recorded as having accumulated in excess of 346,000 flight hours; the type saw considerable action during the South African Border War, supporting counterstrike operations inside neighbouring Angola.
During June 2006, the last Alouette III was officially withdrawn from SAAF service at AFB Swartkop near Pretoria. During February 2013, an interim court order was issued, blocking the proposed sale of South Africa's retired Alouette fleet to the Zimbabwean Air Force.
Capacity: 5 passengers
Length: 10.03 m (32 ft 10¾ in)
Main rotor diameter: 11.02 m (36 ft 1¾ in)
Height: 3.00 m (9 ft 10 in)
Main rotor area: 95.38 m2 (1026 ft2)
Empty weight: 1,143 kg (2,520 lb)
Gross weight: 2,200 kg (4,850 lb)
Powerplant: 1 × Turbomeca Artouste IIIB turboshaft, 649 kW (870 shp) derated to 425 kW (570 hp)
Maximum speed: 210 km/h (130 mph)
Cruising speed: 185 km/h (115 mph)
Range: 540 km (335 miles)
Service ceiling: 3,200 m (10,500 ft)
Rate of climb: 4.3 m/s (850 ft/min)