The Aérospatiale Alouette II, a French light helicopter, was known for its numerous innovations during its time.
It featured a single Turbomeca Artouste II turboshaft engine that had the capability to generate a maximum output of 400 hp.
Unlike traditional helicopters, the Alouette II utilised an automated fuel supply governor to control the speed of its main rotor.
This eliminated the need for a twist-grip throttle and a conventional link between the throttle and the collective-pitch.
Instead, the Alouette II employed a simple control lever arrangement that directly regulated the collective-pitch and activated the governor.
This arrangement ensured that the correct level of power was immediately and automatically applied to match the flight conditions.
With the ability to fly at altitudes reaching 2,286 metres above sea level, the aircraft boasted an average climb rate of 250 metres per minute and a maximum range of 563 miles.
It offered flexibility in landing gear options, allowing for the use of skids, wheels, or pontoons.
The Alouette II had the capacity to seat up to five individuals, including the pilot, and access to the cabin was granted through a pair of side-hinged doors.
The compact cockpit featured a dome-shaped windscreen, ensuring exceptional external visibility.
The Alouette II was a pioneer in the use of armaments, being the first helicopter globally to carry anti-tank munitions such as the SS.11 MCLOS wire-guided anti-tank missile.
The French Army opted for machine guns on their Alouette IIs, while the French Navy equipped theirs with aerial torpedoes for anti-submarine warfare (ASW) missions.
In operational settings, the Alouette II is known to require significant maintenance, with regular lubrication being crucial.
The rotorcraft had 20 grease nipples on the main rotor head alone, necessitating re-lubrication every five flight hours, and the tail rotor drive shaft also demanded attention.
Dust ingestion was a common issue, leading some operators to remove and clean the Alouette’s sand filters after each landing.
Specifications
Crew
1
Capacity
4 passengers
Length
9.66 m (31 ft 8 in) (overall, blades folded)
Height
2.75 m (9 ft 0 in)
Empty weight
895 kg (1,973 lb)
Max take-off weight
1,600 kg (3,527 lb)
Fuel capacity
580 L (150 US gal; 130 imp gal)
Powerplant
1 × Turbomeca Artouste IIC6 turboshaft,
400 kW (530 shp)
Main rotor diameter
10.20 m (33 ft 6 in)
Main rotor area
81.7 m2 (879 sq ft)
Performance
Maximum speed
185 km/h (115 mph, 100 kn) at sea level
Cruise speed
170 km/h (110 mph, 92 kn)
Range
565 km (351 mi, 305 nmi) (with maximum fuel)
Endurance
4.1 hr
Service ceiling
2,300 m (7,500 ft)
Rate of climb
4.2 m/s (820 ft/min).
Sources
Helicopters: An Illustrated History of their Impact-S S McGowen.
How the Helicopter Changed Modern Warfare-W Boyne.
National Air and Space Museum of France.
