Embraer has introduced full fly-by-wire (FBW) to its Legacy 450 and 500 jets, making them the first jets in their class to have such systems.
After successfully running limited FBW in their E-170 and E-190 passenger jets, Embraer took the leap into full FBW with the new Legacy range, making them the only jets with a price tag below $US52 million to have this technology.
FBW removes the direct mechanical and hydraulic links between the side-stick and the control surfaces, saving weight and enabling better performance and a smoother flight.
The technology has enabled Embraer to set "soft limits" on the controls, which means the computer will apply limits to keep the aircraft in the normal operating range, in this case no more than 33o of bank and a pitch range of +30o/-15o. This means if the pilot applies a bank of over 33o, the stick will need to be held there to keep the angle. Should the stick be released, the FBW system will reduce the bank angle to 33o. The same goes for the pitch.
However, there are also hard limits on the FBW, beyond which the system will not allow the aircraft to be flown. For example, the Legacy 450 and 500 can't be stalled. The FBW will automatically over-ride the stick position and reduce the angle of attack before the stall.
Hard limits are applied to structural load, speed, sideslip and angle of attack. There is no hard limit on bank, meaning the Legacy jets can be rolled.
For pilots, this means life gets less stressful, especially in abnormal operations like an engine-out. In these instances, the FBW adopts an optimal slideslip to compensate and make the aircraft much easier to control.
Embraer introduced the system to Australian Flying on a portable simulator at Essendon in mid-September, and demonstrated how a moderately-skilled pilot could control a Legacy easily during a V1-cut exercise.
Another advantage over conventional controls is that the FBW system reduces autopilot oscillations when correcting for turbulence, making for a much smoother recovery.
Now that Embraer has made the move, it will probably force other manufacturers to consider introducing similar systems to their aircraft.
However, the cost of FBW is such that it will probably be some time before it flows down to the shorter-range Phenom 100 and Phenom 300.