The FBW system is different on the 777. The AB philosophy is hard limits and the Boeing soft limits. That philosophy extends into what Boeing believes with the pilot's level of control authority. AB FBW has full control authority and prevents the pilots from making an input controls that would put the aircraft outside it's normal flight envelope. The 777 FBW is not full or complete authority and allows the pilots to fly outside of it's normal envelope. Boeing also believes that that having the more conventional yoke and and column, gives pilots a more realistic feel and feedback of aircraft control. Many pilots believe that they should have the final control of the aircraft. Some pilots like the AB computer controlled protections. And as we known, there are limitations on computer controlled systems and especially if the systems become compromised and "confused". (AF447)
The main concern with full automation, is will pilots become more complacent and rely on on automatics, have less hands on flying experience and in some dire emergency be unable to cope and have less situational awareness? This is the balance that is constantly being sought out between man and their machines. For Boeing, the pilot is always the entity in control and the one who makes the final decisions. Also are not the Boeing controls linked and backdriven so that you can see what is being commanded of the aircraft which gives you the ability to see what the other pilot is doing and what the autopilot is attempting to do? It seems to me IMO, that the Boeing FBW is more transparent. Again, IMO, I like that Boeing allows a greater degree of human intervention.
Also on the 777, when one control yoke is moved by a crew member, the other yoke moves as well. If the autopilot is flying the plane, both yokes will reflect the autopilot's control inputs. Even if the flight crew is busy with charts or messing with the radios, the movement of the yokes in front of them will provide a continuous visual indication of what the autopilot is doing. If the captain is flying manually and the first officer suddenly has to take over or become involved in the control of the airplane, he probably will already have a sense of what's going on control-wise from the movements the yoke has been making in front of him. It's an awareness thing, and can be a critical factor in an emergency situation.
Side sticks do not provide this level of crew awareness. The movement of one stick does not move the other one, hence the non-flying crew member will not be aware of the other person's, or the autopilot's, control inputs other than by instrument indications and by what the airplane is actually doing. Even if the side sticks did move together, their location puts them outside the "awareness bubble" of a non-flying crew member if he's involved with instruments or controls in the center of the panel or on the aisle stand.
And, the Boeing philosophy extends to the throttles. When the engines on a Boeing plane are being controlled by the auto-throttle, the power levers on the aisle stand move to reflect the action of the auto-throttle. The auto-throttle on an Airbus does not move the power levers. They simply remain in the last place they were positioned before the auto-throttle took over. It's that awareness thing again. If the flight control computers determine a power application is needed during some phase of the flight, Boeing pilots will see their power levers move up the quadrant. The only indication Airbus pilots will have is the acceleration of the airplane, possibly the sound of the engines spooling up, and the readings of the engine instruments. In a high-stress, high distraction environment, on final in severe turbulence, for example,these are all things that could be overlooked for several critical moments. That's not to say it's impossible for Boeing pilots to overlook the action of an auto-throttle, but at least they've got some big levers moving under their noses to indicate what's going on.
None of the above may matter to many pilots, but to many others, it will. Just some thoughts.
