PDA

View Full Version : Control movements in large aircraft


AnthonyGA
30th Aug 2008, 13:25
As I have been happily simming in big iron on my PC, I have found, over time, that control movements in airliners seem to work better if I move the controls sharply in order to get the aircraft to start moving, then return them to a neutral position. At least it seems to work better this way than by gently moving the controls and holding them.

Looking at some cockpit videos of pilots hand-flying aircraft like 737s, 767s, 747s, etc., it appears that pilots do this in real life, too. During an approach, for example, I see them turning the yoke a good 30-45 degrees and then immediately returning it to neutral. I find this encouraging, because it implies that I'm doing things right (and that the sim is accurate), but I'd like to confirm.

So … what type of control movements do you find most effective on large airliners? It's it better to move sharply until the aircraft starts to respond, then back to neutral, or can you/should you hold it in place with less movement but longer duration?

This is all for Boeing aircraft. I understand that Airbus doesn't work quite the same way with the sidestick, although I don't understand what the difference is—comments on how the Airbus is flown are welcome.

Also, are the techniques for rudder and elevators different?

The Flying Pram
30th Aug 2008, 14:17
I'm not an airline pilot, but my Microlight is very heavy in roll, and gentle movements don't work except in dead calm conditions. So it's usually a big heave, wait till something happens, then back off and just keep whatever input is needed. The other aspect is the sheer inertia of something like a 747, it's going to take a bit to make it change direction. Otherwise you would be forever having to anticipate and start controlling before you actually needed to turn.

Rainboe
30th Aug 2008, 14:30
No. Wrong! Don't transfer control law from a PC joystick to heavy metal! It doesn't work like that. You fly as if the cabin crew are pouring tea down the back over people, which they probably are! You need a small amount to induce a roll, then you take it almost off, but you should barely be able to see it. I once had a new copilot who seemed to want to fly a 737 like a fighter- I said if you keep flying like that I would take over. Hopefully he is flying sensibly now, with finesse. The 747 flies like any other, it is not a supertanker in the air! With a little finger you can induce a roll or pitch change. I said to new pilots on it they would want to handle it absurdly gently- they must fly it like any other plane. When you are flying it, you are no more aware of inertia than flying a 737.

The Flying Pram
30th Aug 2008, 15:08
Sorry! considering myself duly chastised....
My excuse - such as it is - I don't have any cabin crew pouring tea "over people down the back".

eltonioni
30th Aug 2008, 17:43
A/C controls are not like car steering wheels. They are positioning the a/c in three dimensions so the resultant forces do what you desire. All aircraft, large and small work in the same way.

The simplest example is turning. Bank is applied and when the desired bank is achieved the controls are returned to neutral and the a/c will continue to turn until an opposite command returns the a/c to a level situation.

If you don't remove the bank instruction (i.e. aileron) then the a/c will continue to increase its bank angle.

The OP mentioned the other controls; yes the same applies but do you appreciate what they are for, or that climbing and decending is done with power, not the elevators?


It's a bit more complicated in practice, but that's the essence of it. (For fellow pilots please excuse the shorthand)