The Eurocopter AS 555 Fennec twin-engined shipbourne helicopter belongs to the Ecureuil / Fennec family of helicopters, which also includes the twin-engined civil AS 355 Ecureuil, the single-engine military AS 550 Fennec, civil AS 350 Ecureuil and the civil EC 130 helicopter. Over 3,150 helicopters of the family have been ordered, of which 2,500 have been delivered and are operational in over 70 countries. The AS 555 SN is the naval combat variant and the AS 555 MN is the unarmed naval version.
The helicopters are in production at Eurocopter’s engineering and production facilities at Marignane in France, and they are also built for the Brazilian armed forces under a licensed production agreement by Helibras in Brazil.
The naval variant is in service with the navies of Brazil, Columbia and Argentina. In October 2001, six AS 555SN helicopters were ordered by the Royal Malaysian Navy, which were delivered between 2003 and 2004. They are used for over-the-horizon targeting (OTHT) and training.
The AS 555 is also in service with the French Army. Over 197 fennec helicopters ordered by India were cancelled in December 2007.
AS 555 Fennec helicopter design
The helicopter is of light construction, based on a lightweight metal tailboom and central fuselage with a high-strength, thermoformed, composite cabin. The Starflex main rotor head and the three blades are also of composite materials for added strength and weight reduction. The engine cowlings are armoured for protection.
The helicopter is fitted with armoured seats. The cabin has sliding doors on each side. The 1m³ baggage compartment is installed behind the main cabin with an access door on the starboard side. The helicopter can be equipped with a search and rescue winch and a 1,134kg cargo hook.
For casualty evacuation, the helicopter is equipped with a television optical sensor, forward looking infrared surveillance and searchlights.
As a utility helicopter the AS 555 Fennec can carry two pilots and four troops or loads up to a maximum take-off weight of 2,250kg.
Fennec cockpit systems
The cockpit is equipped with full dual flight controls and is night vision compatible.
The armed naval SN helicopter is equipped with a Thales Avionics Nadir 10 navigation system, a Sagem 85 T31 three-axis autopilot and a Thales Detexis RDN 85 Doppler radar. The navigation suite includes a global positioning system, a VHF omnidirectional radio ranger and instrument landing system (VOR/ILS), an automatic direction finder, distance measuring equipment and a marker beacon transponder. The secure communications systems are fitted according to the customer country’s specification.
Weapon systems
The helicopter is fitted with a wide range of weapon systems to suit the mission and operational requirements of the country’s forces.
The AS 555SN is used for shipborne missions operating from ships above 650t. The helicopter is equipped for anti-submarine warfare and over the horizon (OTH) targeting. The helicopter can carry a lightweight homing torpedo. A chin-mounted Telephonics RDR-1500B X-band, 360° digital colour radar is used for search and surveillance.
The radar also provides weather avoidance, beacon transponder location, and waypoint navigation display. An unarmed naval variant, the AS555MN can also be fitted with the RDR-1500B.
The French Army AS 555AN is armed with a Giat 20mm gun type M621, T-100 sights and Mistral missiles. The helicopter can also be fitted with pylon-mounted rockets.
The AS 555UN French Army helicopter is unarmed for advanced instrument flight rule training with the aviation leger de l’armee de terre and it is also operated as a utility transporter.
Other weapon fits include missiles, rockets and guns including the Forges de Zeebruge rocket launcher carrying seven 2.75in rockets and the Thales Brandt 68mm launcher carrying 12 rockets. The helicopter can be armed with the Giat 20mm gun type M621 and the FN Herstal twin 7.62mm and 12.7mm machine gun pod.
The AS 555 Fennec is also armed with BGM-71 TOW, 7×2.5in Forges de Zeebrugge or 12×68mm Thales Brandt rockets, 20mm Giat M621 cannon, 20mm cannon, and Fabrique Nationale de Herstal twin 7.62mm or 12.7mm machine gun pods.
Turboshaft engines
The helicopter is powered by two Turbomeca Arrius 1A turboshaft engines, mounted to the aft of the transmission. The engines, rated at 302kW continuous power and 357kW take-off power, are equipped with full authority digital electronic control (FADEC) which provides automatic sequenced engine starting.
The engine control restricts the engine performance to remain within the temperature and torque limit envelope and also provides pre-selection of the parameters for one engine inoperable exercises. The two engine drive shafts lead into the single combiner gearbox.
Two integral fuel tanks provide 730l of fuel. In the search and rescue mode and with the capability of carrying two survivors, the helicopter has an operational range of 129km. For long-range operations a 475l auxiliary fuel tank is installed in the cabin. The range with maximum fuel is 694km with no reserves.
Performance
The AS 555 Fennec helicopter can travel at a maximum speed of 278km/h. The service ceiling and the range of the helicopter are 3,800m and 720km respectively. The helicopter’s operating radius is 129km. The endurance and cruise speed of the helicopter are two hours 20 minutes and 217km/h respectively. The maximum take-off weight of the helicopter is 2,600kg.
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