Speedbird744
20th Feb 2001, 20:36
Now, I read that the FBW technology on the 777 protects it from exceeding bank angles, well if (like the 737) there was problems with its rudder inflight where it is jammed, like former 737 accidents, what can FBW do, to stop it from rolling on its back?
How long can the 777 actually fly if both engines fail inflight, is it possible to ditch an aircraft of ITS size into the seA?
Thanks
HighSpeed
21st Feb 2001, 20:41
sb747,
the b777 fbw sys works a little differently from the airbus. when it says it can protect it from exceeding a certain bank angle (35 deg, in this case), the pilot can actually over right this command and 'force' it to bank > 35 deg whereas on the airbuses the flight computers have the final say (unless you switch them off - so i was told).
the b777 rudder sys is different from the b737 rudder design. on the b777, the rudder input is transmitted to the Actuator Control Electronics (ACE) which sends the signal to the Flight Computers for 'verification' (if within limit) before the ACEs moves the control surfaces. if the Flight Computers fail, then the ACEs move the control surfaces based on direct input from the pilots. unless there is an electronic or software problem, a senario similar to the b737 should not be a factor on the b777.
as for how far can a b777 'glides', it depends on how high it was initially. the normal top-of-descent for the b777 from FL330 is 118nm (but bare in mind this is with engines idling. i believe with windmilling engines, the figure could be less).
HS