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Airbus... Why "Autothrust" and not "Autothrottles"

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Airbus... Why "Autothrust" and not "Autothrottles"

Old 29th Jun 2012, 08:21
  #41 (permalink)  
 
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Airbus / Boeing controls

Have never flown either, but from all I've read here, wouldn't the best design be a hybrid of the two designs?

Why not have sidesticks that are coupled, and with control feedback?
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Old 29th Jun 2012, 10:11
  #42 (permalink)  
 
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Wasn't the FBW concept 'borrowed' from Airbus?
Not even close. There were a whole bunch of Fly by Wire aircraft long before the A320, including the Avro arrow, the Space shuttle orbiter, the F-117 and a variety of experimental aircraft.

Airbus may have produced the first FBW airliner, but the concept and successful flying systems were around before airbus existed.
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Old 29th Jun 2012, 13:56
  #43 (permalink)  
 
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aa73;

With all due respect, I would suggest that you keep an open mind, and don't knock something until you try it.

Before I started flying, I too had a number of jumpseat rides (in the days when you could), and the first time I watched a 767 crew fly, I wasn't sure who was flying or exactly how the crew were telling the aircraft to descend etc. But this was only because - at the time - I wasn't an airline pilot, so did not understand airliner SOP's or two crew operations.

Your stated position that control of the A319 was confusing to you does not neccessarily mean that there is anything remotely wrong with the Airbus design, but might mean that you - never having flown one - simply did not understand what was going on. From the jumpseat, it is easy to miss certain subtleties of communication between a professional crew, especially if they are using different SOP's to those you may be used to.

Automatics are becoming good enough to make our lives easier, so why not embrace them? Would you rather fly an aircraft without FADEC's for example? I think most commercial airline pilots would agree that if you actually want to FLY an aeroplane these days, a modern airliner is not the right aircraft - try a Tigermoth or a Pitts Special.

I personally like the fact that an Airbus goes where you point it, and stays in that general attitude until you change it. I also like the fact that it looks after all the pitch-up-in-a-turn and pitch-power couple elements etc.

The age-old 'thrust levers not moving' attitude is becoming a little wearysome. On an Airbus, you watch the PFD. In normal flight; if the speed trend drops towards the bottom of the speed bug, you expect to see the thrust increase, so you glance at the NI or EPR gauges, where you see the engines wind up a little. You get the information through your eyes instead of through your hand - what's the problem? After all, the fact that the thrust levers on a Boeing have moved might not mean that the engines have spooled up - you still need to check the gauges to confirm the engines are responding to the command. One advantage with the Airbus philosophy might be that no-one's hands are on thrust levers unless they are manually controlling the thrust (ie, autothrust is disengaged), or preparing to take over from the autothrust. So the other pilot has more situational awareness.

Try it first perhaps, then comment.

Regards

U

Last edited by Uplinker; 29th Jun 2012 at 14:02.
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Old 29th Jun 2012, 17:16
  #44 (permalink)  
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Thanks Uplinker, you're 100% correct: I will refrain from commenting until I fly it one day. For all I know, I may change my mind.

Regarding my terms, forgive me -all I know is Boeing and McD/D. I have been using throttles, control yokes, and power settings for years now. I guess I am old school... "Autothrust" just does not cut it for me. I'm a firm believer in visual cues, and I not only want to see N1/EPR gauges move, I want to see the throttles move along with them! It reinforces what the aircraft is doing, and I believe this was a huge contributing factor in the crash of AF447 - the lack of visual cues as to what the other pilot was doing. Apparently I'm not the only one.

I'm also an old school type of flier. I hand fly my 75/76 usually up to FL180, and on descent hand fly from 10,000ft to landing. And when I mean hand fly, I mean switching off A/P, A/T, and sometimes the F/D if it's a nice day. Keeps my skills sharp, and maybe, just maybe, would be my saving grace should everything quit on some dark night over the Atlantic. From what I've been told, the Airbus is not a friend of "hand flying."

As of right now, under AA's new proposed TA - if it passes - the A319 will pay the worst out of all US Airbus operators. So if I don't bid onto it, most likely due to the crappy pay!

Last edited by aa73; 29th Jun 2012 at 17:22.
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Old 30th Jun 2012, 11:25
  #45 (permalink)  
 
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The thrust levers not moving does take a bit of getting used to. In the end your eyes stop looking for a movement of the levers and look for changes on the EPR/N1 gauge. After a few hundred hours you don't even notice it.
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Old 30th Jun 2012, 14:17
  #46 (permalink)  
 
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FIRST OFF...the only great airliner maker , DOUGLAS, calls them THROTTLES.

SECOND OFF, at best, whatever airbus calls them, they are really only ENGINE ROOM TELEGRAPHS

or perhaps engine rheostats?

And it is interesting about how humans glean their info. I found out about five years after I'd been flying one particular type, that the SIMulator had a volume control for engine sound. It was always turned DOWN so you couldn't hear the engines in the sim.

Turning it up made me hear the engines going out of synch on an engine cut even before I saw it on the panel.

Ergo, we still get INFO from many sources, not just our eyes.


remember when planes warned you of a stall when the flying wires sang: nearer my God to thee?

and we shouldn't say MINIMA...we should say Decision Height on an ILS.

Last edited by sevenstrokeroll; 30th Jun 2012 at 14:19.
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Old 3rd Jul 2012, 11:44
  #47 (permalink)  
 
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From what I've been told, the Airbus is not a friend of "hand flying."
Who told you that? They are easier to fly accurately than an aircraft with conventional flying controls.
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Old 3rd Jul 2012, 21:30
  #48 (permalink)  
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My USAir and Delta buddies who fly the A320 series both say that it wasn't really designed for hand flying. They say there is no "feel" to the stick, and the fact that there is no trim takes a lot of the fun out of hand flying. They also say Airbus designed it to be operated on autopilot as much as possible, with the cockpit philosophy mainly designed for third world countries whose pilots will most likely be flying the Airbus with not much total flying time/experience.

It may be easier to hand fly than a conventional aircraft, but then again the whole point of hand flying is to maintain piloting skills.... and you can't (and won't ever) convince me that flying an A320 series is improving my piloting skills. Sorry, but not having pitch trim to work with, plus letting go of the stick and the aircraft autotrimming itself for bank/pitch is almost like having the A/P on already.

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73

Last edited by aa73; 3rd Jul 2012 at 21:31.
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Old 3rd Jul 2012, 21:58
  #49 (permalink)  
 
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They are easier to fly accurately than an aircraft with conventional flying controls.
You kinda missed the point there.
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Old 4th Jul 2012, 16:43
  #50 (permalink)  
 
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Your last 6 words there hit the nail on the head, aa73 !

As I've said on another thread, the Fly-by-wire Airbus autopilot is effectively always in ! - Those 5 computers are doing a lot of the flying for you; (trim, pitch in turns etc.) (Not all 5 at once - they back each other up).

Instead of the autopilot disconnect being between the autopilot and the control surfaces; when you "disconnect the autopilot" on a FBW Airbus, the FBW stays connected to the control surfaces, and what you are actually changing is where the FBW gets it's pitch and roll guidance from: The FMGS, the FCU (glareshield), or you via your sidestick.

If you take manual control, the FBW system is still controlling the elevators and ailerons + spoilers with reference to accelerometers. These are used to check that a commanded control input has taken sufficient effect, (but is not too much that it would stress the airframe). The accelerometers also mean that the aircraft can - to a certain degree - try to keep it's attitude through turbulence. This is why one can get into PIO's - by not realising that the FBW system is making corrections too.

I've found that the key is not to continuously correct, but just guide the aircraft. On the very worst day though; in strong turbulence, or an on-limits crosswind approach and landing; you will be moving the side stick against it's stops to keep the aircraft pointing where you want it. This is difficult to describe, but you do get used to it.

It is not traditional 'stick-and-rudder flying', certainly, and obviously not everyone likes it, but it is easy to do, and ultimately one still has full control of where and how the aircraft is going. It is fun to fly too - I promise you.


I've thought of another analogy for the non-moving thrust levers too: In an automatic car, one doesn't see the gearstick actually moving, but you know from other cues that the gears are being changed according to the conditions and your driving commands. In addition, you can tell the gearbox whether you want to go forward or back, and can limit which gears are used, (on ice for example).

U

Last edited by Uplinker; 4th Jul 2012 at 16:56.
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Old 5th Jul 2012, 13:13
  #51 (permalink)  
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Thanks Uplinker, great analogies!

I suspect maybe once I fly it I'll be on here preaching its assets.

Great discussion!
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Old 5th Jul 2012, 20:47
  #52 (permalink)  
 
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The point is not if the throttles move or not.Important is thrust changes when needed.

That`s why.
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Old 7th Jul 2012, 01:54
  #53 (permalink)  
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The point is not if the throttles move or not.Important is thrust changes when needed.

That`s why.
Not quite sure what you mean by that comment.

My question alludes to the fact that I think an important visual cue is lost when the throttle movements don't match the actual engine thrust. However, most Bus pilots here acknowledge the fact that one gets used to it after awhile - and if that means that no SA is lost, all the better.
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