The Eurocopter AS350 Ecureuil ("Squirrel") and AS355 Ecureuil 2 are a family of light helicopters originally manufactured by Aérospatiale (now part of Eurocopter Group). The AS350 (marketed as the AStar in North America) is the single-engined version, while the AS355 (TwinStar) uses two engines. The EC130B is a recent adaptation of the AS350 airframe.

Design and development

Development began in the early 1970's to replace the Alouette II, and the first flight took place on 27 June 1974. A twin-engined version, known as the Ecureuil 2, Twin Squirrel, or in North America as the TwinStar, first flew on 3 October 1979. Despite the introduction of the EC130, production of the Eurocopter AS350 and AS355, and the AS550 and AS555 Fennec military versions remains strong.

Both single and twin-engined versions have been built under licence by Helibras in Brazil.

Operational history

On May 14, 2005 a standard-configured Ecureuil AS350 B3 piloted by Eurocopter test pilot Didier Delsalle touched down on the top of Mt. Everest, at 8,850 meters (29,035 feet) . This record has been confirmed by the Fédération Aéronautique Internationale.

Variants

Single engine

AS350 - Prototype.

AS350 Firefighter - Fire fighting version.

AS350B - Powered by one Turbomeca Arriel 1B engine.

AS350 B1 - Powered by one Turbomeca Arriel 1D engine.

AS350 B2 - Higher gross weight version powered by one Turbomeca Arriel 1D1 engine.

AS350 B3 - High-performance version, is powered by a Turbomeca Arriel 2B engine equipped with a Full Authority Digital Engine Control (FADEC) system. This helicopter is the first ever to land on Mount Everest. Recently introduced AS350 B3/2B1 variant introduces enhanced engine with dual digital FADEC, dual hydraulics and a 2,370 kg (5,225 lb) M.T.O.W.

AS350 BA - Powered by a Turbomeca Arriel 1B engine and fitted with wider chord main rotor blades.

AS350 BB - AS350 B2 variant selected to meet rotary-wing training needs of UK MoD, through its Defence Helicopter Flying School in 1996. Powered by a derated Turbomeca Arriel 1D1 engine to improve the helicopters' life cycle.

-- Eurocopter Squirrel HT.1 - Designation of AS 350BB in operation with British RAF as a training helicopter.

--Eurocopter Squirrel HT.2 - Designation of AS 350BB in operation with British Army Air Corps as a training helicopter.

AS350 C - Initial variant of Lycoming LTS-101-600A2 powered version developed for the North American market as the AStar. Quickly superseded by AS350D.

AS350 D - Powered by one Lycoming LTS-101 engine for the North American market as the AStar. At one stage marketed as AStar 'Mark III.'

AS350 L1 - Military derivative of AS350 B1, powered by a 510-kW (684-shp) Turbomeca Arriel 1D turboshaft engine. Superseded by AS350 L2.

AS350 L2 - Military derivative of AS350 B2, powered by a 546-kW (732-shp) Turbomeca Arriel 1D1 turboshaft engine. Designation superseded by AS550 C2.

HB350 B Esquilo - Unarmed military version for the Brazilian Air Force. Brazilian designations CH-50 and TH-50. Built under licence by Helibras in Brazil.

HB350 B1 Esquilo - Unarmed military version for the Brazilian Navy. Brazilian designation UH-12. Built under licence by Helibras in Brazil.

HB350 L1 - Armed military version for the Brazilian Army. Brazilian designation HA-1. Built under licence by Helibras in Brazil.

Twin engine

AS355 - Prototype of the twin-engined Ecureuil 2 or Twin Squirrel.

AS355 E - Initial production version, powered by two Allison 250 turboshaft engines. Known as the Twin Star in the United States and Canada.

AS355 F - Improved version, fitted with improved rotor blades and systems.

AS355 F1 - Powered by the Allison C20F engine. 2,400 kg (5,291 lb) M.T.O.W.

AS355 F2 - Powered by the Allison C20F engine with uprated engine and transmission for higher M.T.O.W. (2,540 kg or 5,600 lb), and hydraulic accumulator for better tail rotor control.

AS355 M - Initial armed version of AS355 F1.

AS355 M2 - Armed version of AS355 F2. Superseded by AS555 Fennec.

AS355 N Ecureuil 2 - Version fitted with two Turbomeca Arrius 1A engines and a Full Authority Digital Engine Control (FADEC) system for better M.T.O.W (2,600 kg or 5,732 lb) and better single engine performance. Known as the TwinStar in the United States.

AS355 NP Ecureuil 2 - Introduced in 2007, this version is fitted with two Turbomeca Arrius 1A1 turboshaft engines and a new AS350 B3-based main gearbox, increasing maximum take-off weight to 2,800 kg (6,173 lb).

HB.355F Ecureuil 2 - Licence built in Brazil by Helibras.

HB.355N Ecureuil 2 - Licence built in Brazil by Helibras.

Aftermarket conversions

Soloy Super D - AS350 BA powered by an LTS101-600A-3A engine.

Soloy Super D2 - AS350 B2 powered by an LTS101-700D-2 engine.

Heli-Lynx 350FX1 - AS350 BA powered by an LTS101-600A-3A engine.

Heli-Lynx 350FX2 - AS350 BA or AS350 B2 powered by an LTS101-700D-2 engine.

Otech AS350BA+ - AS350 BA powered by an LTS101-600A-3A engine.

Heli-Lynx 355FX1 - Powered by the Allison C20F engine. FAA, TC, and EASA approved.

Heli-Lynx 355FX2 - Powered by the Allison C20F engine. FAA,TC and EASA approved.

Heli-Lynx 355FX2R - Powered by the Allison C20R engine. FAA and TC approved.

Starflex AS355F1R - AS355 F1 powered by the Allison C20R engine. FAA, TC and EASA approved.

Starflex AS355F2R - AS355 F2 Powered by the Allison C20R engine with optimised tail rotor blades. FAA, TC and EASA approved.

Operators

Military operators

Albania
Algeria
Australia - Australian Army, Royal Australian Air Force, Royal Australian Navy, Fleet Air Arm (RAN), No. 723 Squadron RAN
Benin
Botswana
Brazil
Burkina Faso
Burundi
Cambodia
Canada
Central African Republic
Chile - Chilean Army AS350 & HB355
China
Comoros
Denmark
Djibouti
Ecuador
France
Gabon
Guinea
Jamaica
Malawi
Malaysia
Mali
Mauritius
Mexico
Morocco
Nepal
Paraguay
Peru
Rwanda
Singapore
Trinidad and Tobago
Tunisia
United Arab Emirates
United Kingdom - 38 AS350 BB helicopters in service with FB Heliservices for the Ministry of Defence's Defence Helicopter Flying School at RAF Shawbury for training all British Armed Forces helicopter pilots.
Uruguay
Venezuela

Law Enforcement operators

Austria - Flugpolizei (Ministry of Interior) operates five AS350 B1, two AS355 F2, and two AS355 N.
Australia - New South Wales Police Force
Bosnia and Herzegovina - Federal Police
Brazil - Brazilian Federal Police, Brazilian Military Police, Goiás Military Police
Canada - Royal Canadian Mounted Police, Ontario Provincial Police
Chile - Policía de Investigaciones de Chile
Ireland - Garda Síochána
Morocco - Royal Moroccan Gendarmerie
Netherlands - Netherlands Coast Guard for use at Curacao (Netherlands Antilles)
New Zealand - New Zealand Police Air Support "Eagle Unit"
Norway - Norwegian Police Service
Philippines - Philippine National Police
South Africa - South African Police Service Air Wing operates 11 AS350B3s.
Trinidad and Tobago - Special Anti-Crime Unit of Trinidad and Tobago
United States - Anaheim Police Department operates an AS350 B2 helicopter, Baltimore County Police Department recently purchased three Eurocopter AS350B3 helicopters, Bernalillo County Sheriff Department operates an AS350 B3 helicopter, Broward County Sheriff's Office operates an AS350 B2 helicopter, California Highway Patrol operate 10 AS350 B3 helicopters and a single AS350 B2, Citrus County Sheriff's Office operates a single AS350 B3 helicopter, Dekalb County Police operate 2 AS350 B2 helicopters, East Bay Regional Park Police operates an AS350 B2 helicopter, Hillsborough County Sheriff's Office operates 3 AS350 B2 helicopters, Lee County Sheriff's Office operates two AS350B/B2 helicopters, Los Angeles Police Department operates 14 AS350 B2 helicopters, Los Angeles County Sheriff's Department operates 12 AS350 B2 helicopters, Massachusetts State Police operates 4 AS355 N TwinStar helicopters and an AS350 BA, Memphis Police Department operates an AS350 B3 helicopter, Oakland County Sheriff's Department operates 2 AS350 B2 helicopters, Ohio State Highway Patrol operates an AS350 B2 helicopter, Ontario, CA Police Department operates 2 AS350 B2 helicopters, Orange County, CA Sheriff's Department operates 2 AS350 B2 helicopters, Phoenix Police Department operates 3 AS350 B3 helicopters, Pinellas County Sheriff's Office operates 2 AS350 B2 helicopters, Riverside County Sheriff's Department operate 4 AS350 B3 helicopters, Salt Lake County Sheriff operates an AS355 N helicopter, San Antonio Police Department operates an AS350 B3 helicopter, San Bernardino County Sheriff's Department operates 6 AS350 B3 helicopters, San Diego Police Department operates 4 AS350 B3 helicopters, Suffolk County Police Department operates 1 Eurocopter EC145 and 2 Eurocopter AS350 B2 helicopters, Texas Department of Public Safety operates three AS350 B and nine AS350 B2 helicopters, U.S. Customs and Border Protection operates 48 AS350 helicopters, and in July 2008 signed a multi-year contract for up to 50 additional AS350 B3s to meet its Light Enforcement Helicopter requirement, U.S. Immigration and Customs Enforcement operate several AS350 B2 and AS350 B3 helicopters, U.S. Drug Enforcement Agency operates two AS350 B2 helicopters, Utah State Highway Patrol operates 2 AS350 B2 helicopters, Washington DC Metro Police Department operates 2 AS350 B3 helicopters.

Civilian operators

Australia - Australian Helicopters operates transfers from Gladstone, Queensland to Heron Island. The Australian Antarctic Division uses the Eurocopter AS350 for intra-continental air operations in Antarctica.
Bhutan
Brazil
Canada - CHC Helicopter Corporation
Chile - DAP Helicópteros (355), Ecocopter (350), Helicopters.cl (350B3), Kipreos (350BA), SumaAir (350B3)
Finland - Heliflite Oy in the arctic Finland
Germany
Greenland - Air Greenland
Hungary - 3 AS350 B in service with Hungarian Air Ambulance Service, all of them received general overhaul in 2005-2007.
Iran - Iranian helicopter service company (IHSC)
Iceland - 1 AS350 B2 is operated by Northflight, also do they have one more on its way.
Nepal
Puerto Rico - Puerto Rico Electric Power Authority
United Arab Emirates
United Kingdom

Accidents and incidents

On 14 January 1986, French singer and songwriter Daniel Balavoine and Thierry Sabine, founder of the Dakar Rally, crashed into a dune during a sandstorm in Mali.

On 22 October 1996, Chelsea Football Club Vice Chairman Matthew Harding together with five companions were killed when their AS355 F1 Squirrel, registration G-CFLT, crashed near Middlewich, Cheshire.

On 27 July 2007, two AS350s collided in mid-air while reporting a police pursuit.The two helicopters were part of KNXV-TV and KTVK television stations in Phoenix, Arizona. Four crew members were killed by this accident.

On 15 September 2007, former World Rally Championship driver Colin McRae and three passengers were killed when his AS350 B2 Squirrel, which he was piloting, crashed near Lanark, Scotland.

On 24 May 2008, an AS350 crashed on the west end of Catalina Island, killing the pilot, Emeric Maillet, and two passengers along with critically injuring three other passengers.

Specifications (AS350 B3)

General characteristics
- Crew: 1
- Capacity: 6
- Length: 12.94 m (42.45 ft)
- Rotor diameter: 10.69 m (35.07 ft)
- Height: 3.24 m (10.63 ft)
- Empty weight: 1,241 kg (2,736 lbs)
- Max takeoff weight: 2,250/2,570 kg (4,960/5,225 lbs)
- Powerplant: 1× Turbomeca Arriel 2B or 2B1 turboshaft, 632 kW (847 shp)

Performance
- Never exceed speed: 287 km/h (155 knots, 178 mph)
- Cruise speed: 259 km/h (140 knots, 161 mph - Fast cruise (127 knots normal cruise speed).)
- Range: 657 km (355 nm, 408 mi)
- Service ceiling 5,044 m (16,550 ft)
- Rate of climb: 10.0 m/s (1,959 ft/min)