Turboméca manufactures Arrius turbo shaft engines for a wide range of helicopters, including the Eurocopter AS355N (Arrius 1A), EC135 (2B) and EC120 (2F) and McDonnell Douglas MD901 (2C). The engine has an electronic control system for twin-engined helicopters, and hydro-mechanical control for singles. The Arriel 2 engine powers the Eurocopter AS350B3 (Arriel 2B), AS365N3 (2C) and Sikorsky S76C (2S1).
The Arriel 2 differs from the earlier Arriel 1 in having a single-stage gas-generator turbine, with single-crystal blades, and a single-channel electronic control unit.
Source: Flight International