The American manufacturer, Bell, decided to dispense with traditional mechanical flight controls on their Bell 525 Relentless, to make it the first civilian helicopter equipped with fly-by-wire flight controls. The 9 metric ton (19,800lbs.) aircraft made its maiden flight on 1 July at Amarillo, Texas.
This follows the choice made by NHIndustries in equipping their NH90 twenty years ago. The multi-role military helicopter is the first in the world to be equipped with fly-by-wire flight controls. These systems link the pilot’s controls and the two helicopter rotors to offer better handling and increased stability in piloting terms. Jacques Bellera, Head of Flight Control System Department at Airbus Helicopters: "With traditional mechanical flight controls, the connection between the pilot’s Cyclic Stick Control and rotors is done with mechanical rods. In the case of fly-by-wire flight controls, the mechanical rods are replaced by computers. You have electrical connection cables between the pilot’s control stick and the computer, and the computer and rotor blades’ actuators."
Thanks to the four on-board computers, the NH90 is also safer. One suffices to fly the helicopter; the three others are there as backup in case of failure or physical impacts, when in operation, for example.
The fly-by-wire controls render the 11 metric ton (24,000lbs.) aircraft as easy to handle as a light helicopter. After the NH90 and the Bell 525, it is a safe bet that this technology will now become widespread in helicopter cockpits, at least for the heavier versions, being the most difficult to pilot.
