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Aircraft cannot make banking turn


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12 hours ago, ianyikos said:

Something about the aerodynamics isn't allowing the planes to bank left or right.  The aerodynamic force should make it turn according to this article.

What article, that's an image of a pickup truck

Edited by Val
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19 hours ago, ianyikos said:

Something about the aerodynamics isn't allowing the planes to bank left or right.  The aerodynamic force should make it turn according to this article.

I've never had any issues with a banking turn. It's a little ackward on a keyboard since A & D are mapped to yaw, not roll.

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I understand what you're saying, but I just feel like there's something wrong or something, since any plane supposedly just turns if it rolls to the side.This article says a paper airplane turns if it rolls to the side.  https://www.grc.nasa.gov/www/k-12/airplane/alr.html  

https://www.grc.nasa.gov/www/k-12/airplane/objmotion.html

Edited by ianyikos
Adding more informative links about how planes turn, and adding response to previous reply
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2 hours ago, ianyikos said:

since any plane supposedly just turns if it rolls to the side.This article says a paper airplane turns if it rolls to the side.

I fly an airplane in real life sometimes and let me tell you, you need to pull back on the stick after you roll, or you're just going to be falling out of the sky "vaguely" to one side. (Ie. you need to pitch after you roll to turn.)

And really, that's a combat turn; typically you only roll very slightly (not entirely up onto your side) then you apply some yaw and pitch with your roll and do a "co-ordinated" turn.

Edited by Rocket In My Pocket
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8 hours ago, ianyikos said:

I understand what you're saying, but I just feel like there's something wrong or something, since any plane supposedly just turns if it rolls to the side.This article says a paper airplane turns if it rolls to the side.

As @razark says: if you have SAS on hold (the default when it's on), it is actively working against any attitude changes, including turns. You can't directly compare that to a paper airplane that does not actively steer at all.

To get your plane to act like a paper airplane and see how rolling does indeed result in turning in KSP, turn SAS off and use trim. With a well-built plane, you could also use SAS prograde and see the same thing. In both cases you need to also be flying in a state of equilibrium: speed, altitude and thrust should be at balance for that specific plane - otherwise the unbalanced forces will tend to have more effect than what the roll will do. The best situation to see this in effect is in stable cruising flight.

I've never flown an actual plane like others here, but I do fly a lot in KSP, and I can tell you that in stock KSP planes do turn when rolled/banked. When I am doing long-distance flights in KSP and the destination is still far off, a slight roll (and no pitch) is how I correct deviations from my intended heading. It exchanges a tiny bit of altitude for a slow turn back towards the correct heading. You tend to gain a bit of speed too, which is exchanged again for the lost altitude after you level out the roll. It's a pretty smooth and stable way of adjusting your heading in KSP. And because it's performed without pitching, you avoid fighting SAS if it's set to follow prograde (with the current SAS code, pulling away from prograde can easily cause very unpleasant self-amplifying see-sawing, so it's something to avoid whenever possible).

For faster turns (close to the destination or in chase/dog-fighting), or just generally when flying with SAS on hold, you will need to add pitch to the roll, as @Rocket In My Pocket says.

 

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Is SAS on?  If so, then that's the culprit.  It's not that the plane won't turn in a bank, it's that SAS actively FIGHTS that turn by pushing the controls the other way under the false impression you view a change in heading as a rotation in need of suppressing.

SAS tries to suppress *all* rotation by pushing the controls the other way, including the heading change that comes with a banked  turn.  SAS is too 'dumb' to know that you're trying to fly a plane not a rocket, so this activity isn't desirable.

The main reason people get in the habit of flying with SAS on is because it's impossible with the all-or-nothing keyboard controls to try to hold the elevator pitched up just slightly, which is what you usually need for a stable flight.  And most people don't know the trim controls exist because trim does nothing when SAS is turned on so even if you find the controls in the key bindings (it's ALT+WASDQE keys, or ALT-X to re-center), when you try using them you don't see any effect with SAS on, so you learn to ignore that part of the game.  (The trim only affects where the controls get centered when you let go of them and SAS never lets go of them so you can't see the effect when it's on.)

My advice for planes - first test your plane design *without* SAS, instead using ALT-S and ALT-W to move the pitch trim to make it fly smooth.  If you cannot get the plane to fly nice this way and need the SAS on, then it's a bad design.

*After* you have a good design, then use SAS only for one thing:  Turn it on *after* you get the wings level and are flying in a boring long flight in a straight line, in order to let you physics warp up to 4x.  Manual control under Physics warp is a Pain, where SAS is needed because physics warp inserts bogus phantom rotations that are not present at 1x speed, causing your ship to roll if SAS is off, and at the mangified control authority of 4x physics warp, there's no way you can correct these nicely, so you lametably need SAS for physics warp in planes.

But don't use SAS when trying to do a banked turn.

To turn to a new heading, turn SAS off, make the turn without it, level off and fly straight on the new heading, then turn SAS back on. Only have SAS on when you want to fly in a straight line for a while.

 

 

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On 10/12/2018 at 3:36 PM, ianyikos said:

since any plane supposedly just turns if it rolls to the side.

This is only true for planes that are built to be both dynamically and passively stable. However, it is easy to build unstable planes -- both in real life and in KSP. And unstable planes have many benefits; in fuel consumption, maneuverability, and many other ways.

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