Treeny From United Kingdom, joined Dec 2005, 319 posts, RR: 0 Posted (6 years 5 months 2 weeks 4 days 5 hours ago) and read 7699 times:
Hi All
Before I say anything please dont turn this into an A vs B posting that was not my intention.
I was wondering why Airbus went for throttle levers that remain at idle during flight whereas Boeing's move and respond. Is there any advantage in this in terms of saving fuel like in a car for example where we all now that continuously pressing the throttle consumes more fuel that say, in cruise control.
The other thing I wondered was whether this had any effect on my own opinion that Boeings ride is smoother than Airbus's. It seems that because the throttles react to whats happening it may assist but I am only guessing.
Although the control of thrust I guess is the same or a similar mechanism, does anybody know the reason why the levers move in Boeings design but not in that of Airbus?
Bucky707 From United States of America, joined Aug 2000, 1028 posts, RR: 4 Reply 1, posted (6 years 5 months 2 weeks 4 days 5 hours ago) and read 7663 times:
Keep in mind, on the Airbus, though the throttle levers don't move, the engines are still being contolled with the autothrottle.
as to why, I don't know. I like having the throttle levers move. I like the feedback I get, especially when flying without the autopilot.
Aviator27 From , joined Dec 1969, posts, RR: Reply 3, posted (6 years 5 months 2 weeks 4 days 4 hours ago) and read 7562 times:
Quoting Treeny (Thread starter): I was wondering why Airbus went for throttle levers that remain at idle during flight whereas Boeing's move and respond. Is there any advantage in this in terms of saving fuel like in a car for example where we all now that continuously pressing the throttle consumes more fuel that say, in cruise control.
The other thing I wondered was whether this had any effect on my own opinion that Boeings ride is smoother than Airbus's. It seems that because the throttles react to whats happening it may assist but I am only guessing.
Although the control of thrust I guess is the same or a similar mechanism, does anybody know the reason why the levers move in Boeings design but not in that of Airbus?
Airbus throttles have 4 detents. TOGA (Take-off/Go Around), Flex/MCT (Maximum Continuous Thrust), Climb, and Idle.
For takeoff, the pilot pushes the throttles up to TOGA for maximum thrust, or Flex/MCT for reduced thrust on longer runways or less than maximum weights. At 1000 or 1500 feet, the pilot moves the throttles to the CLIMB detent where they stay for the rest of the flight. Although the FADEC adjusts the engine thrust to maintain airspeed, the throttles do not move. The FADEC can control the thrust from maximum climb thrust to flight idle while the throttle is in the CLIMB detent and the auto thrust is active. During the flare, the pilot moves the throttles to idle.
The throttles are linked to the FADEC (Full Authority Digital Engine Control) by electronic signals, not by cables as in Boeings. This reduces weight (similar to FBW controls). Airbus also has brake by wire, thus extending the weight reduction idea of having no cables extending from the cockpit to the brakes.
Your view that Boeing flies smoother than Airbus is purely subjective and has no basis in scientific facts. In fact, Airbus airplanes are designed for smoother flight with soft altitude hold and load alleviation functions. These are systems that Boeing is now designing into the B787 for the first time ever (they claim its ground breaking). I will add the Lockheed was the first manufacturer to have these functions in their airplanes some 40+ years ago.
Boeing puts a motor into their throttle quadrant to make the throttles move to make pilots feel more comfortable. It has no effect on the actual control of the engines because they also use FADECs. Its the same as Boeing keeping a control yoke instead of switching to joystick. Some pilots feel better grabbing the yoke. This is only because they have never used a sidestick and they feel it wouldn't work. I once flew Boeings and now I fly Airbus and I can tell you, the sidestick is much easier. All my fears about using the sidestick went out the window within minutes of touching the airplane.
These are thoughts and opinions of an airline pilot. I hope I have answered your questions.
TristarSteve From Sweden, joined Nov 2005, 3690 posts, RR: 34 Reply 4, posted (6 years 5 months 2 weeks 4 days 1 hour ago) and read 7478 times:
Quoting Aviator27 (Reply 3): The throttles are linked to the FADEC (Full Authority Digital Engine Control) by electronic signals, not by cables as in Boeings
B767 (most of them) B744 and B777 all have electric throttles. But they move under autothrottle control.
Bucky707 From United States of America, joined Aug 2000, 1028 posts, RR: 4 Reply 5, posted (6 years 5 months 2 weeks 4 days 1 hour ago) and read 7470 times:
Quoting Aviator27 (Reply 3): The FADEC can control the thrust from maximum climb thrust to flight idle while the throttle is in the CLIMB detent and the auto thrust is active. During the flare, the pilot moves the throttles to idle.
question for you. If you want, can you turn off the autothrottles and control the thrust manually?
EMBQA From United States of America, joined Oct 2003, 9286 posts, RR: 13 Reply 7, posted (6 years 5 months 2 weeks 4 days ago) and read 7407 times:
Quoting Treeny (Thread starter): I was wondering why Airbus went for throttle levers that remain at idle during flight whereas Boeing's move and respond.
Boeing is very much into giving the crew as much 'feel' as they can as to how the plane is acting and responding even as we go to a more fly by wire control.
"It's not the size of the dog in the fight, but the size of the fight in the dog"
Troubleshooter From Germany, joined Feb 2005, 423 posts, RR: 5 Reply 8, posted (6 years 5 months 2 weeks 3 days 23 hours ago) and read 7390 times:
Quoting Aviator27 (Reply 3): The throttles are linked to the FADEC (Full Authority Digital Engine Control) by electronic signals, not by cables as in Boeings
The CFM56-7B engines on the B737NG are FADEC controlled. Each thrust lever has one resolver assembly with two resolvers (one for each EEC channel) which converts thrust lever position into thrust lever resolver angle (TRA) for EEC (FADEC) input. There is no mechanical linkage between the thrust lever and the engine!
HighFlyer9790 From United States of America, joined Jul 2005, 1236 posts, RR: 0 Reply 9, posted (6 years 5 months 2 weeks 3 days 17 hours ago) and read 7296 times:
not to go off topic but in boeings, the control coloumn also responds to what the autopilot does where as the airbus joy stick stays motionless.
Professional people mover. A to B. CL-65 Type; CFI/CFII/MEI/AGI/IGI
Wrldwndrer From Canada, joined Dec 2006, 22 posts, RR: 1 Reply 10, posted (6 years 5 months 2 weeks 1 day 13 hours ago) and read 7143 times:
Again, maybe going off topic a bit. How do the throttles on other manufacturers aircraft with autothrottles behave ? Embraer, Bombardier, Dassault, Gulfstream, etc. ?
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