Eurocopter AS355

The Eurocopter AS355 Ecureuil 2 (Twin Squirrel) is a twin-engine light helicopter originally manufactured by Aérospatiale in France (now part of Eurocopter Group). The AS355 is marketed in North America as the TwinStar.

Design and development
Development began in the early 1970s 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 28 September 1979. Despite the introduction of the EC130, production of the Eurocopter AS350 and AS355, and the AS550 and AS555 Fennec military versions remains strong.

Twin engine

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


 * AS355 E
 * Initial production version, with single hydraulics, powered by two Allison 250-C20F turboshaft engines.


 * AS355 F
 * Improved version, with dual hydraulics and increased maximum weight of 2,300 kg (5,070 lb).


 * AS355 F1
 * Powered by two Allison 250-C20F engines, 2,400 kg (5,291 lb) Maximum weight.


 * AS355 F2
 * Powered by two Allison 250-C20F engines, 2,540 kg (5,600 lb) Maximum weight and a yaw compensation system.


 * 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 Superseded by AS555 Fennec.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, tail rotor strake added along starboard side of tail boom for better yaw authority.


 * 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 Esquilo Bi
 * Assembled in Brazil by Helibras (part of Eurocopter).


 * HB.355N Esquilo Bi
 * Assembled in Brazil by Helibras.

Aftermarket conversions

 * 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
The AS355 is used by both private individuals and companies, helicopter charter and training organizations as well as law enforcement and government use.

Military and government operators

 * Algerian Air Force
 * Border Guard
 * Brazilian Air Force
 * Brazilian Navy
 * Royal Cambodian Air Force
 * Ontario Provincial Police
 * Chilean Army
 * Djibouti Air Force
 * Jamaica Defence Force
 * 🇲🇼 Malawi
 * Malawi Army
 * Royal Malaysia Police
 * New Zealand Police
 * Ministry of Interior
 * 🇷🇼 Rwanda
 * Rwandan Defence Forces
 * National Navy of Uruguay
 * Massachusetts State Police
 * Malawi Army
 * Royal Malaysia Police
 * New Zealand Police
 * Ministry of Interior
 * 🇷🇼 Rwanda
 * Rwandan Defence Forces
 * National Navy of Uruguay
 * Massachusetts State Police
 * Rwandan Defence Forces
 * National Navy of Uruguay
 * Massachusetts State Police
 * Massachusetts State Police
 * Massachusetts State Police

Former operators

 * Bophuthatswana
 * Bophuthatswana Air Force
 * Garda Air Support Unit
 * Garda Air Support Unit

Accidents and incidents

 * 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.
 * In July 1998, the Kent Air Ambulance, a AS355 F1 Squirrel, crashed in good weather after colliding with power cables near Burham whilst returning to Rochester Airport following an aborted call to attend a road accident. All three crew - the pilot, Graham Budden, and two paramedics, Tony Richardson and Mark Darby - were killed on impact.
 * In May 2007, Chelsea Football Club Vice President Philip Carter, founder of training company Carter and Carter, crashed in his part-owned Twin Squirrel registration G-BYPA returning from Liverpool John Lennon Airport after watching Chelsea play Liverpool F.C..
 * On 18 August 2011, a AS-355F-2 (reg No/ VH-NTV) crashed near Lake Eyre in South Australia resulting in 3 fatalities. The Helicopter was owned by the Australian Broadcasting Corporation. On board were, Gary Ticehurst (abc chief helicopter pilot for 25 years), John Bean (cameraman) and Paul Lockyer (journalist). All three had 20 years or more experience working for the ABC.
 * On 20 October 2011, the Eurocopter twin-engine helicopter crashed at 3:45 p.m. (1245 GMT) near the village of Vileity and burst into flames. A Belarus border patrol helicopter crashed Thursday near the Lithuanian border, killing all five people on board, including three members of a television crew, the agency said.