|Aerospatiale AS.350 Ecureuil|
Once it became possible to relay live pictures from helicopters, many broadcasters rushed to buy their own machines. Within 18 months there were more than 100 in use across the United States alone. But operating in this way was veiy expensive, and it became more common to charter an aircraft when it was needed to cover a specific story or event.
The AS 350's main advantages for news-gathering operations are reliability and performance. Good reserves of power, simple flight controls and rapid response mean that the pilot can concentrate on the subject and does not need to be concerned about the machine's limitations.
This is particularly important when the pilot is also the reporter. Keeping clear of other helicopters, respecting minimum height regulations and handling the controls, while selecting the right shot to illustrate the story and describing the scene to viewers, is a full-time job.
In spite of the expense, if a helicopter can get to the scene of a major event as it is happening, or to the aftermath of a natural disaster, there is no substitute for the sense of immediacy it can provide.
R.Jackson "Helicopters. Military, Civilian, and Rescue Rotorcraft", 2005
First flown in June 1974 the Ecureuil was designed for the civilian market and introduced many features including the Aerospatiale 'Starflex' rotor system. Built from composites/fibre-glass, the rotor head was designed without the need for conventional mechanical hinging. It used the inherent flexibility of laminated composites for movement. This replaced the old style bearings and introduced laminated self-lubricating bearings. Fibre-glass was also used in the tail-rotor, formed by two blades attached to a composite beam which is both torsional and flexible and allowed the hinge system to be replaced. Aerospatiale also employed a large amount of composites within the fuselage, allowing for weight reduction, anti-corrosion and reduced operating costs. Powered by a single Turbomeca Arriel turbine-engine the AS.350 is produced in a civil and military variant and these have sold well overseas in both versions.
P.Allen "The Helicopter", 1996
If the Alouette II represented the first family of French helicopters, the Puma the second generation and the Dauphin the third, the Ecureuil (Squirrel) is essentially a fourth generation, not just in terms of technology and performance, but above all, in the efforts made to simplify the production process, bringing assembly line techniques for helicopters increasingly close to those for ordinary motorcars.
The AS.350 in fact uses many automobile parts such as a cooling fan from a normal Citroen car and an oil radiator by another automobile manufacturer, while the Starflex rotor has very few parts, thereby eliminating the need for lubrication. Metal blades have also been abandoned in favour of fiberglass reinforced plastic ones which have a virtually unlimited life. The use of composite materials and pressed parts has contributed a great deal to simplifying the production process. The spacious cabin, for instance, is made of thermoformed polycarbonate semi-monocoque sections with ultrasonic welding. The bearings usually found in rotor hubs have been replaced by elastomeric ball joints which need no lubrication.
The first prototype of the AS.350 with a Lycoming LTS engine flew in January 1974 and the second (with a French Turbomeca Arriel engine) in February 1975. Deliveries began in July 1978 after eight pre-production models had been built. By the end of December of that year, the company had 459 orders for machines of this type, only six of which were for the military version. Essentially a civil helicopter, therefore, it has been a big success in the United States, where it was called Astar and customers could opt for an American or French engine.
G.Apostolo "The Illustrated Encyclopedia of Helicopters", 1984
TYPE: Light utility helicopter.
PROGRAMME: First flight (F-WVKH) powered by Lycoming LTS101 turboshaft 27 June 1974; first flight second prototype (F-WVKI) powered by Turbomeca Arriel 1A February 1975; first production version was AS 350B powered by 478kW Arriel IB and certified 27 October 1977; LTS101 powered AStar sold only in USA. AS 350BA Ecureuil was powered by 478kW Turbomeca Arriel 1B and fitted with large main rotor blades of AS 350B2; maximum T-O weight increased by 150kg; AS 350B upgraded to AS 350BA in field; replaced AS 350B during 1992; French VFR certification 1991; UK and US certifications 1992, Japanese 1993. Production of AS 350BA ended in 1998.
Delivery of the 2,000th AS 350/550 (F-WWPZ, later ZJ270 of UK Defence Helicopter Flying School) effected in July 1997. In February 2001, delivery effected of 3,000th of Ecureuil family (including AS 355/555), which also was first EC 130 upgraded version. Total 10,986,000 Ecureuil flying hours by January 2001.
Built at Marignane, France, and under licence by Helibras in Brazil. See also CHAIG Z-11.
AS 350B2 Ecureuil: Uprated engine and transmission; wide-chord new section main and tail rotor blades originally developed for AS 355 twin; certified 26 April 1989; known as SuperStar in North America; supplied to UK Ministry of Defence as AS 350BB, designated Squirrel HT. Mk 1 with normal instrumentation and Squirrel HT. Mk 2 with provision for pilot's NVGs.
AS 350B1, 350BA and 350B versions can be upgraded to 350B2.
AS 350B3 Ecureuil: Current variant; 632kW Arriel 2B and wide-chord tail rotor; optimised for high-altitude operation; uprated transmission and digital engine control. First flight (F-WWPB) 4 March 1997; French VFR certification December 1997 after 150 hour test programme; first delivery, to Osterman Helicopter, January 1998; Australian and New Zealand certification achieved late 1998. By 1 June 2001, 180 AS 350B3s were in service with 120 customers, in 25 countries; 100th AS 350B3 delivered 14 December 1999 to Japanese customer.
AS 350D AStar: Version of 350B for North American market; improved LTS101 engine, with 6% more power, offered early 1999.
AS 350 Firefighter: Conair system able to pick up water load in 30 seconds while hovering over water; demonstrated 1986; Isolair system certified September 1995.
AS 550СЗ Fennec: Light anti-tank version armed with four TOW missiles; has same power plant as AS 550A3 and 2 hour 45 minute endurance.
AS 550A3 Fennec: Light attack version of AS 350B2 with 3-hour endurance; powered by 632kW, Arriel 2B; standard features include taller landing gear, sliding doors; NVG-compatible cockpit; reinforced airframe; provision for armoured seats and engine cowlings; can be armed with single 20mm cannon or two rocket launchers.
AS 550U3 Fennec: Military utility version with Arriel 2B power plant; capable of performing observation, commando and transport duties.
EC 130: Described separately.
Military customers include Singapore armed forces (10 AS 550B2 and 10 AS 550C2); Australia (RAAF 18 for training; RAN six utility); Danish Army (12 AS 550C2 with ESCO HeliTOW system ordered 1987, delivered 1990); French Army ALAT (originally expressed need for up to 100 to replace Alouette III); French CEV (flight test centre), and FBS Ltd, which ordered 38 AS 350BBs, with deliveries beginning November 1996 and service entry in April 1997. Of these, 26 are Squirrel HT. Mk Is with Defence Helicopter Flying School at Shawbury and 12 are NVG-compatible HT. Mk 2s with 670 Squadron, Army Air Corps, at Middle Wallop; by June 2001 the fleet had amassed 100,000 hours. Other orders include 11 for Brazilian Navy fox liaison and patrol work; 30 for Brazilian Air Force for training; 36 for Brazilian Army (16 for liaison and 20 for training and firefighting); six AS 350B3 for Chilean Army; eight for China (see also CHAIC Z-11) and 40 AS 350B2 options for US Customs Service (augmenting five B2s delivered from 21 October 1998 to supplement 19 earlier AStars); six AS 550C3; 13 AS 350B3 ordered by United Arab Emirates in 2000; and four AS 350B3 for the South African Police Air Wing, of which last two delivered in January 2002. Orders in 1997-2002 were 102, 73, 95, 137, 103 and 132. Deliveries in 2002 were 163.
COSTS: AS 350B3 US$1.4 million (2002).
DESIGN FEATURES; Conventional pod-and-boom design with power plant above cabin; fin, underfin and twin horizontal stabilising surfaces. Starflex bearingless glass fibre main rotor head; all versions now have lifting section composites main rotor blades. Main rotor turns at 394 rpm, tail rotor at 2,086 rpm.
FLYING CONTROLS: Single fully powered controls with accumulators to delay manual reversion following hydraulic failure until airspeed can be reduced; cyclic trim by adjustable stick friction; inverted aerofoil tailplane to adjust pitch attitude m climb, cruise and descent; saucer fairing on rotor head to smooth wake, swept fins above and below tail. Variety of autosiabiliseis and autopilots available.
STRUCTURE: Main rotor head and much of airframe of glass fibre and aramids; main rotor blades automatically manufactured in composites; self-sealing composites fuel tank in military versions.
LANDING GEAR: Steel tube skid type. Taller version standard on military aircraft. Emergency flotation gear optional.
POWER PLANT: AS 350B2 powered by one 546kW Turbomeca Arriel 1D1 with transmission rated at 440kW for T-O; AS 35OB3/AS 550C3 powered by one 632kW Turbomeca Arriel 2B turbine engine controlled by FADEC, with transmission rated at 500kW for T-O; AS 350D powered by AlliedSignal LTS101 sold only in USA. Plastics fuel tank (self-sealing on AS 550) with capacity of 540 litres. Optional 475 litre auxiliary tank in cabin.
Soloy offers conversion using Rolls-Royce 250-C30M turboshaft.
ACCOMMODATION: TWO individual bucket seats at front of cabin and four-place rear bench standard, optional two-place front bench seat; optional ambulance layout; large forward-hinged door on each side of versions for civil use. Optional sliding door at rear of cabin on port side; (sliding doors standard on military version); baggage compartment aft of cabin, with full-width upward-hinged door on starboard side; top of baggage compartment reinforced to provide work platform on each side.
SYSTEMS: Hydraulic system includes four single-body servo units, operating at 40 bar pressure, and accumulators to delay reversion to manual control; electrical system includes a 4.5kW engine-driven starter/ generator, a 24V 16Ah Ni/Cd battery and a ground power receptacle; cabin air conditioning system optional.
AVIONICS: Comms: VHF/AM radios, HF/SSB transponder and ICS.
EQUIPMENT: Options include 907kg capacity cargo sling (1,160 kg for AS 350B2/550, 1,400 kg on AS 350B3), 135kg capacity electric hoist (optional 204kg on AS 350B3), a TV camera for aerial filming, SX-16 searchlight, Wescam and FLIR observation systems, and a 735 litre Simplex agricultural spraytank and boom system.
ARMAMENT (AS 550C3): Provision for wide range of weapons, including 20mm Giat M621 gun, FN Herstal TMP twin 7.62mm and 12.7mm machine gun pods. Thomson Brandt 68.12 launchers for twelve 68mm rockets, Forges de Zeebrugge launchers for seven 70mm rockets, and ESCO HeliTOW anti-Tank missile system.
Jane's All the World's Aircraft, 2004-2005
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- A Textron Lycoming-engined version of the Ecureuil is marketed in North America as the Astar.
- By 1 March 1989 Ecureuils and Astars were flying in 43 countries.
- Most of the AS 350's outer skin is made from thermo-formed plastic.
- An uprated electrical system on the Ecureuil 2 makes it particularly suited to the TV reporting role.
- Apart from its twin engines, the AS 355 Ecureuil 2 is similar to the AS 350.
- The Ecureuil is still in production, and is now built by Eurocopter.
- The first flight of the AS 350 occurred on 24 June, 1974, followed by a second example on 14 February, 1975.
- A fully-armed version of the Ecureuil is capable of launching anti-tank missiles.
- The helicopter has been assembled under licence in Brazil.
- A gunship version of the Ecureuil has a 20mm cannon and twin gun pods.
- Emergency flotation gear can be fitted to the skids for operations over water.