Full sidetick 320 in gusts
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I'm positive airbus manuals fail to make people understand how to handle the stick because way too many airbus pilots mix mayonnaise in gusty winds.
It is simple: wait a moment, let the computer (FCS, not AP, not CWS) to stop the bank angle excursion, then make your input. Airbus texts make people believe that the system will keep ILS till touchdown if you leave the sidestick neutral...
Uplinker
Are you airbus fbw type rated? That is not what the FCS system does...
Airbus fbw airplanes just have a different kind of stability, that's all. They are path stable rather than speed stable. To achieve that you need a feedback loop, much like that of an AP, there is no other way. But handling the sidestick has nothing to do with a CWS system.
In a conventional cessna there are two inputs, as well: airplane stability characteristics and pilot inputs. In the bus these characteristics are different, and heavily affected by the FCS, yes. Same applies to the 777. But it is in no way like an AP or a CWS, and airbus pilots must have very clear the difference between pitch, pitch rate, g load, bank angle and roll rate among others.
A good airline pilot has to know very well his AFS, and also his FCS. Many are rluctant to do thhe latter in airbus because it is "weird" or something. Then they don't trust the airplane which leads them to hate it (cos Yoda was right, fear brings hate, and then you have a lot of airbus pilots in the dark side)
It is simple: wait a moment, let the computer (FCS, not AP, not CWS) to stop the bank angle excursion, then make your input. Airbus texts make people believe that the system will keep ILS till touchdown if you leave the sidestick neutral...
Uplinker
Are you airbus fbw type rated? That is not what the FCS system does...
Airbus fbw airplanes just have a different kind of stability, that's all. They are path stable rather than speed stable. To achieve that you need a feedback loop, much like that of an AP, there is no other way. But handling the sidestick has nothing to do with a CWS system.
In a conventional cessna there are two inputs, as well: airplane stability characteristics and pilot inputs. In the bus these characteristics are different, and heavily affected by the FCS, yes. Same applies to the 777. But it is in no way like an AP or a CWS, and airbus pilots must have very clear the difference between pitch, pitch rate, g load, bank angle and roll rate among others.
A good airline pilot has to know very well his AFS, and also his FCS. Many are rluctant to do thhe latter in airbus because it is "weird" or something. Then they don't trust the airplane which leads them to hate it (cos Yoda was right, fear brings hate, and then you have a lot of airbus pilots in the dark side)
Stilton; no, the sidesticks do not move together.
At the risk of thread creep; I personally think that is a design flaw and I think they should move together. If the other pilot has his/her tray table out, you cannot see their sidestick, or what inputs they are making.
Neither does the aircraft autopilot or A/THR backdrive the sidesticks or the thrust levers. I personally am not bothered about the static thrust levers, because my normal flying scan includes the engine instruments. I have been flying the Airbus FBW for many years now, and so I am not bothered about not seeing the other pilots sidestick inputs, because I know how the aircaft is going to react and I can tell if the other pilot is doing something wrong. However, if I was a training Captain or a brand new trainee then I am sure that I would prefer to see the opposite sidestick inputs, or feel them copied on my side. And when I was a trainee, I think I would have got the hang of flying the Airbus FBW much quicker if I could have "followed through" on the controls.
Micro; Yes I am, thanks. The problem here, as I have said, is with terminology. My previous answers are not necessarily accurate in terms of exactly which black box is doing what, or what you want to call it, but are trying to convey what flying the FBW is like for those who have not experienced it or are trying to learn.
NO: the Airbus FBW will NOT hold the exact attitude you left it at, but it will TRY. NO; it will not hold an ILS unless the autopilot is flying it - but I never said it would.
At the risk of thread creep; I personally think that is a design flaw and I think they should move together. If the other pilot has his/her tray table out, you cannot see their sidestick, or what inputs they are making.
Neither does the aircraft autopilot or A/THR backdrive the sidesticks or the thrust levers. I personally am not bothered about the static thrust levers, because my normal flying scan includes the engine instruments. I have been flying the Airbus FBW for many years now, and so I am not bothered about not seeing the other pilots sidestick inputs, because I know how the aircaft is going to react and I can tell if the other pilot is doing something wrong. However, if I was a training Captain or a brand new trainee then I am sure that I would prefer to see the opposite sidestick inputs, or feel them copied on my side. And when I was a trainee, I think I would have got the hang of flying the Airbus FBW much quicker if I could have "followed through" on the controls.
Micro; Yes I am, thanks. The problem here, as I have said, is with terminology. My previous answers are not necessarily accurate in terms of exactly which black box is doing what, or what you want to call it, but are trying to convey what flying the FBW is like for those who have not experienced it or are trying to learn.
NO: the Airbus FBW will NOT hold the exact attitude you left it at, but it will TRY. NO; it will not hold an ILS unless the autopilot is flying it - but I never said it would.
Last edited by Uplinker; 10th Feb 2013 at 07:25.
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I think the CWS remarks come from a description I was certainly given on the conversion to the "Other Side" which described the manual controls as acting much like CWS on the Boeing, ie you select an attitude with the sidestick and the system holds that until you make another selection. It is a good way of describing what the system does, but bears little resemblance as to how it does it. That's my guess at where this idea has crept in.
As to handling in turbulence I too was surprised at how easy it is to reach the limit on stick deflection (so far only in roll) but as the aircraft clearly remains in control if not - according to one classic definition - under control it seems a relatively normal regime of flight. I thoroughly endorse Micro's remarks about making mayonnaise - ALL the turbulence handling difficulties I've observed in my FOs have been due to gross overcontrolling, whipping the stick around like its a Pitts. All this does is to destabilise the aeroplane and make it more skittish and thus harder to fly. The trick in my opinion - just like then737 - is to consciously slow down control inputs and increase their amplitude, ie bigger and slower movements. This can be surprisingly exaggerated (think stirring treacle instead of whipping mayo) and always results in a more responsive and easier to control flightpath. The idea - I think - is largely to ignore the wiggles and bumps - they tend to self cancel - and just fly out the bigger slower excursions with proportionally bigger, slower inputs. It works for me. The more you let the Airbus fly itself the better it seems to respond which is of course exactly the design philosophy.
Personally in extreme turbulence I'd take the Boing every time but I don't think there's much in it. The Airbus flies just fine in turbulence if you use the right technique and remember it is a big, inertia heavy airliner not a Pitts or F16 and treat it as such.
As to handling in turbulence I too was surprised at how easy it is to reach the limit on stick deflection (so far only in roll) but as the aircraft clearly remains in control if not - according to one classic definition - under control it seems a relatively normal regime of flight. I thoroughly endorse Micro's remarks about making mayonnaise - ALL the turbulence handling difficulties I've observed in my FOs have been due to gross overcontrolling, whipping the stick around like its a Pitts. All this does is to destabilise the aeroplane and make it more skittish and thus harder to fly. The trick in my opinion - just like then737 - is to consciously slow down control inputs and increase their amplitude, ie bigger and slower movements. This can be surprisingly exaggerated (think stirring treacle instead of whipping mayo) and always results in a more responsive and easier to control flightpath. The idea - I think - is largely to ignore the wiggles and bumps - they tend to self cancel - and just fly out the bigger slower excursions with proportionally bigger, slower inputs. It works for me. The more you let the Airbus fly itself the better it seems to respond which is of course exactly the design philosophy.
Personally in extreme turbulence I'd take the Boing every time but I don't think there's much in it. The Airbus flies just fine in turbulence if you use the right technique and remember it is a big, inertia heavy airliner not a Pitts or F16 and treat it as such.
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The best advice I was given, was also the first advice I was given. It is an airplane, just fly it like an airplane and don't worry about the FBW.
The number of times I "notice" that the airplane is not reacting quite like I wanted it to is extremely small. Maybe once or twice a year and only in moderate turbulence. And it is only because the FBW is faster than I am, and is already deflecting the control surfaces in the way they need to be deflected. I just got clued in a fraction of a second later.
The number of times I "notice" that the airplane is not reacting quite like I wanted it to is extremely small. Maybe once or twice a year and only in moderate turbulence. And it is only because the FBW is faster than I am, and is already deflecting the control surfaces in the way they need to be deflected. I just got clued in a fraction of a second later.
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I recall I tended to over-control the side stick during the first two sim sessions of my initial
endorsement. The advice I got was "Stop handling it like a virgin with her first c0ck!"
endorsement. The advice I got was "Stop handling it like a virgin with her first c0ck!"
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Yes, it is like PIOs in other airplanes. In the bus maybe we can't term them as PIOs, everything regarding stability and control is non conventional in the bus, but they are very similar, and so is the solution to them.
Sorry for blasting you about the CWS thing, but I hate that concept. I much prefer the special stability point of view.
My idea is that the system stability stops the deviation at some point, and after that, we put the airplane back on its due position. The stick should be neutral or close to neutral most of the time, with occasional or frequent small inputs. No need for full stick. If the gust Induces a large roll rate, the system can and will coup with it very well without our help. After that ther is no need for full stick, just enough to gently put wings level.
I used to do the full stick thing often in the beginnin, as soon as I noticed each gust, and sometimes I managed to keep wings very level, but when the gust frequency increased, then I made the finest mayonnaise...
Sorry for blasting you about the CWS thing, but I hate that concept. I much prefer the special stability point of view.
My idea is that the system stability stops the deviation at some point, and after that, we put the airplane back on its due position. The stick should be neutral or close to neutral most of the time, with occasional or frequent small inputs. No need for full stick. If the gust Induces a large roll rate, the system can and will coup with it very well without our help. After that ther is no need for full stick, just enough to gently put wings level.
I used to do the full stick thing often in the beginnin, as soon as I noticed each gust, and sometimes I managed to keep wings very level, but when the gust frequency increased, then I made the finest mayonnaise...
I think most of us on this thread are in agreement with each other, but have different ways of trying to express it.
Stilton, you need to fly an Airbus FBW before making such comments. Once you have experience on it, a FBW Airbus is very easy to fly - it just needs a different technique, and an appreciation of what the FBW system is doing for you. This is something that is very poorly trained, in my experience - like most of us I was just told treat the sidestick as a dockers c**k and all those sort of comments, which are extremely unhelpful and give you no information to help you fly it properly.
Here's how I fly it: I let the FBW do the flying, and, if it's not coupled to any Nav source, (FCU,FMGS,ILS), then every so often, if the atmosphere has disturbed the flight path; I gently nudge it back to where I want it to go. I hold the side stick properly and make a series of short duration, short travel 'nudges' and back to neutral each time and look at the result. I don't hold a deflection until the attitude is where I want it because then it will over shoot and I will have to bring it back = PIO. I make a 'nudge' in the direction I want and back to neutral and see what the result is. If it was not enough, I make another 'nudge', etc. If I am flying straight and level and then I want to change the attitude by a greater amount, such as a roll into a turn, I hold the stick at maybe half deflection and release it to neutral as the aircraft approaches the attitude I want, then correct if necessary by small nudges.
Effectively what you are telling the FBW is where to hold the attitude. If it is holding a roll attitude a bit too far right, then nudge left a couple of times to 'step' the attitude across to where you want it. The FBW will reset it's 'datum' and then hold the new attitude, until a strong gust or you move it again. If you are flying through very strong turbulence, don't worry if you need to put in full deflections - you won't break anything - but only hold full deflection for a few seconds* and then go back to neutral. If you find yourself making constant inputs and alternately going from one deflection to it's opposite sense, then you are fighting the FBW. Let it do most of the work and just concentrate on guiding it.
It may still sound weird, but it is much easier to experience than explain.
* NOTE: for Windshear or GPWS - hold the stick back until clear.
Stilton, you need to fly an Airbus FBW before making such comments. Once you have experience on it, a FBW Airbus is very easy to fly - it just needs a different technique, and an appreciation of what the FBW system is doing for you. This is something that is very poorly trained, in my experience - like most of us I was just told treat the sidestick as a dockers c**k and all those sort of comments, which are extremely unhelpful and give you no information to help you fly it properly.
Here's how I fly it: I let the FBW do the flying, and, if it's not coupled to any Nav source, (FCU,FMGS,ILS), then every so often, if the atmosphere has disturbed the flight path; I gently nudge it back to where I want it to go. I hold the side stick properly and make a series of short duration, short travel 'nudges' and back to neutral each time and look at the result. I don't hold a deflection until the attitude is where I want it because then it will over shoot and I will have to bring it back = PIO. I make a 'nudge' in the direction I want and back to neutral and see what the result is. If it was not enough, I make another 'nudge', etc. If I am flying straight and level and then I want to change the attitude by a greater amount, such as a roll into a turn, I hold the stick at maybe half deflection and release it to neutral as the aircraft approaches the attitude I want, then correct if necessary by small nudges.
Effectively what you are telling the FBW is where to hold the attitude. If it is holding a roll attitude a bit too far right, then nudge left a couple of times to 'step' the attitude across to where you want it. The FBW will reset it's 'datum' and then hold the new attitude, until a strong gust or you move it again. If you are flying through very strong turbulence, don't worry if you need to put in full deflections - you won't break anything - but only hold full deflection for a few seconds* and then go back to neutral. If you find yourself making constant inputs and alternately going from one deflection to it's opposite sense, then you are fighting the FBW. Let it do most of the work and just concentrate on guiding it.
It may still sound weird, but it is much easier to experience than explain.
* NOTE: for Windshear or GPWS - hold the stick back until clear.
Last edited by Uplinker; 11th Feb 2013 at 14:17.
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In normal law, in roll, the 777 behaves pretty much like the 320, not having flown it... In a conventional airplane you might have to keep some aileron to maintain zero roll rate, depending on several effects, if you are climbing or descending, etc... FBW eliminates that and will tend to keep roll rate zero with neutral stick or yoke.
I regard the airbus as a "trimless" airplane, rather than an autotrim airplane. The reason being that the sidestick has no speed related feeling (it doesn't have to, since it is a path stable system and not speed stable). In the bus, we trim the airplane when we release the stick at the desired flight path. Even when the THS is jammed or unavailable we can still trim the airplane, with the sidestick, when in alternate law. Same applies to roll. It is like a roll autotrim. No need to keep stick deflection to maintain zero roll rate. Release to neutral and that is it.
In very nice to fly conventional airplanes, the pilot will only "intervene" with occasional slight push or pull forces in the stick, if the airplane is properly trimmed. input, trim, relax, slight deviation, small input, retrim if needed, etc... in both pitch and roll. In a not so nice to fly one you have to constantly make inputs, the airplane never seems to be in trim for longer than a few seconds. The airbus, and the 777 and 787 behave like the very nice to fly one.
I regard the airbus as a "trimless" airplane, rather than an autotrim airplane. The reason being that the sidestick has no speed related feeling (it doesn't have to, since it is a path stable system and not speed stable). In the bus, we trim the airplane when we release the stick at the desired flight path. Even when the THS is jammed or unavailable we can still trim the airplane, with the sidestick, when in alternate law. Same applies to roll. It is like a roll autotrim. No need to keep stick deflection to maintain zero roll rate. Release to neutral and that is it.
In very nice to fly conventional airplanes, the pilot will only "intervene" with occasional slight push or pull forces in the stick, if the airplane is properly trimmed. input, trim, relax, slight deviation, small input, retrim if needed, etc... in both pitch and roll. In a not so nice to fly one you have to constantly make inputs, the airplane never seems to be in trim for longer than a few seconds. The airbus, and the 777 and 787 behave like the very nice to fly one.
