If the control system in an Airbus is fly-by-wire, then what is the control system in Boeings? How does it work? What are its general differences from the fly-by-wire?
Boeing uses a more direct approach to control (but both systems have warnings). In short it boils down to who has final authority of control surface actuation. Fly by wire does not just mean that control surfaces are controlled electronically (even the Cessna 172 has electric flaps) but that a computer in some way takes the pilot (or pilots) inputs and generates a control surface output. In the airbus case the computer has the final say, so if the pilot commands the plane to do something it should not, the computer will not move the control surfaces and allow it to enter such an attitude or speed. Boeing takes the reverse view and gives the pilot final authority so what ever control inputs are made translate to control surface movements.
With that in mind Boeing does have things like a yoke shaker in the event of approaching a stall and a yaw damper etc. Airbus will allow full control surface actuation with Direct Law however the plane is not normally in this mode. Boeings Standard protections and augmentations is similar but will allow the pilot to enter the conditions
"...to inform the pilot that the command being given would put the aircraft outside of its normal operating envelope, but the ability to do so is not precluded." (source)
On the contrary vertical stick motion in an airbus in flight actually controls load factor and not necessarily pitch directly. So its always some form of proportion to the aircrafts speed.
If memory serves Boeing control surfaces are set up such that movement of one yoke will move the other yoke in tandem, likewise they can not be simultaneously moved in opposite directions while airbus controls can be moved in opposite direction and the computer will summate the inputs (although an override button is present on each stick to disconnect the others should something be improperly acting on it).
Using a pure definition of fly-by-wire, both Boeing and Airbus airliners can be considered fly-by-wire.
- Boeing has built some FBW airliners (777, 787) and some that aren't (707/720, 737, 747, 757, 767).
- Airbus has built some FBW airliners (A320 series, A330, A340, A350, A380) and some that aren't (A300, A310).
Fly-by-wire (FBW) is a system that replaces the conventional manual flight controls of an aircraft with an electronic interface. The movements of flight controls are converted to electronic signals transmitted by wires [...], and flight control computers determine how to move the actuators at each control surface to provide the ordered response.
With that description in mind, both manufacturers build FBW aircraft. Pilots' control inputs are translated into aircraft flight control surface movements by a set of redundant computers.
Boeing's first FBW airliner was 1994's 777, and their only other pure-FBW design is the 787. The 748 is a partial-FBW design. Both the 777 and 787 have some computer-enforced limits in place to keep the aircraft within the flight envelope, but those limits can be overridden, and the aircraft generally are said to 'feel like a normal airplane'.
Airbus's first FBW airliner was the 1987's A320, and all their subsequent designs are FBW. Airbus's control logic is much less direct than Boeing's, containing full flight envelope protection in the 'Normal Law' configuration, and correspondingly less protection if the aircraft reverts to 'Alternate Law' mode (which is roughly comparable to Boeing FBW). None is provided in what is called 'Direct Law', where the computers simply pass commands directly to the flight control surfaces.
That said, both manufacturers build fly-by-wire airliners
Boeing is to fly by wire as Airbus is to fly by computer, would probably be closer to the mark.
Both are fly by wire, but Boeing is closer to direct input - I move the yoke halfway to the limit, the controls move halfway to their limit
While Airbus is a suggestion to the aircraft as to what you'd like it to do - I move the side stick halfway to the limit, and the plane performs that action at something like half the rate the performance envelope should allow.