Rudder Coordination Exercises- what the heck is the rudder for????

[Gooseneck]

Thanks for the track Crummp. But you were losing up to 4000fpm in those 'coordinated' turns. The slipball was centred, but your roc (variometer) was all over the place. You pulled up initially, but then lost altitude quite alarmingly.

 

Am I missing the point?

[Crumpp]

Am I missing the point?

 

Kind of yeah....

 

It is not steep turns and the airplane will not hold altitude or fly at a 90 degree bank.

 

 

Don't even look at the slip ball. It is not accurate when the aircraft is in motion, only once a maneuver is settled. Look at the moments of the nose. The nose rotates straight around the longitudinal axis.

[Echo38]

you were losing up to 4000fpm in those 'coordinated' turns. The slipball was centred, but your roc (variometer) was all over the place. You pulled up initially, but then lost altitude quite alarmingly.

 

"Coordinated" doesn't say anything about altitude gain or loss, or how smooth the maneuvers look. Coordinated simply means no slip or skid. You can lose loads of energy while coordinated, and you can gain energy while uncoordinated, just as the inverse is true for both. The point of coordination is primarily that flying any given maneuver coordinated will result in less energy loss than the same maneuver performed uncoordinated, all else equal.

 

It's also going to make you less spin-prone if you stall, at low power settings; with high power settings (at low speed), engine torque may necessitate that you use more rudder (to fight the torque) than is required to coordinate, in the last few moments before the stall. So, it's a bit counter-intuitive, but, under certain conditions, in conventional prop aircraft with high powerloading, you may be less spin-prone while flying at a specific state of uncoordination during the incipient stage, than when perfectly coordinated during the same. However, in general, being coordinated is going to make you less spin-prone in stalls, especially in modern aircraft.

Edited October 10, 2015 by Echo38

[Crumpp]

It's just that flying any given maneuver coordinated will result in less energy loss than the same maneuver performed uncoordinated, all else equal.

 

Exactly. Which is why folks stall out instead of making a defensive break turn.

[Gooseneck]

Aaah, gotcha. So this is simply about rudder/aileron coordination only? Ok.

 

By the way, there's a useful clickbox in the options menu called 'align controls to HOTAS at mission start' or something like that, so you can trim out your a/c for a given throttle setting, then restart the mission already trimmed out. Helps save time when making demos. :thumbup:

[Crumpp]

By the way, there's a useful clickbox in the options menu called 'align controls to HOTAS at mission start' or something like that, so you can trim out your a/c for a given throttle setting, then restart the mission already trimmed out. Helps save time when making demos.

 

Thanks. I am not much of desktop flyer until DCS came along. I am still learning.

 

It's a case of way more time in the real thing than I do the virtual.

[Crumpp]

So this is simply about rudder/aileron coordination only? Ok

 

Yes, the correct amount of rudder to make a coordinated turn in maneuvering flight where the ball does not give you any useful information is just enough to rotate the aircraft precisely about the longitudinal axis.

 

http://images.slideplayer.com/22/6400822/slides/slide_4.jpg

 

You use the rudder to eliminate any movement about the vertical axis.

 

That is coordinated flight. If you build that muscle memory for what "looks" right, you will not have to refer to the slip and ball indicator which is not accurate when maneuvering.

 

It takes just a tiny amount of rudder input and leading the ailerons by a fraction of second. That is the purpose of doing the coordination exercise, to build the muscle memory to make fast coordinated turns required in a dogfight.

Edited October 10, 2015 by Crumpp
clarity

[iborg]

Thanks for the tips Crumpp ! A handle I remember from my Warbirds days, a long time ago BTW S!

[Crumpp]

Thanks for the tips Crumpp ! A handle I remember from my Warbirds days, a long time ago BTW S!

 

You are most welcome. Yeah I have fond memories of Warbirds. I enjoyed working on the FM's. Too bad we only got the Bf-109E4 and Spitfire Mk 1 finished. They then tried to rush the changes which disappointed me.

 

Good group of folks over there! :thumbup:

[Gooseneck]

I even added some top rudder a few times.

 

Ok, this question is probably more to do with gyroscopic gunsights than it is to do with flying per se, but Crumpp's track got me checking myself today.

 

Here's the thing; if I maintain a perfectly coordinated level turn, the gunsight reflex disappears off of the glass. I need to put in masses of top-rudder and thus induce lots of side-slip in order to get the gunsight reflex back on the glass.

 

I'd expect the reflex to disappear in a steep turn, but these turns were fairly gentle, and the gunsight reflex disappeared off to the side. Lots of top rudder required to bring it back.

 

Can someone explain this please?

Edited October 10, 2015 by Dooyar

[Crumpp]

Sounds like gyroscopic procession. When a turn is uncoordinated the Load factor is asymmetrical and the resultant force is applied over multiple vectors.

 

The load factor is not asymmetrical when the turn is coordinated so the resultant is not divided over multiple vectors.

 

The floor of the aircraft remain down (load factor remains on the Z axis) so the resultant force on a gyro will experienced 90 degrees and your sight disappears to the side.

Edited October 10, 2015 by Crumpp

[Crumpp]

BTW, the sight should eventually come back once the turn is established and the gyro settles down.

[Gooseneck]

BTW, the sight should eventually come back once the turn is established and the gyro settles down.

 

Yah. Annoying though isn't it? I guess many folk would shoot first rather than wait for the sight to catch up, and slipping to use the sight during the drift would prob result in a miss.......

 

I guess I just prefer a fixed reflector and deflection rings.

[Sporg]

Actually I always switch off the gyro and just use it as a fixed sight. :)

[Tomsk]

Amazing!

 

I'd always heard people talking about "Coordinated Turns" and "Keeping the Ball Centered" but I honestly never understood it ...

 

That's because it's really not "Coordinated Turns" it's actually (watching your tracks and the videos) "Coordinated Rolls". And you don't achieve them by watching the ball (which as you say is too unstable) but by watching the nose!

 

Seems that I have a new thing to practice with my flying now :-)

[Crumpp]

Amazing!

 

I'd always heard people talking about "Coordinated Turns" and "Keeping the Ball Centered" but I honestly never understood it ...

 

That's because it's really not "Coordinated Turns" it's actually (watching your tracks and the videos) "Coordinated Rolls". And you don't achieve them by watching the ball (which as you say is too unstable) but by watching the nose!

 

Seems that I have a new thing to practice with my flying now :-)

 

:thumbup:

 

This is exactly why I made the tracks. When I was a CFI I had students in the real world, including some very experienced pilots, who did not understand it until it was demonstrated in the air.

 

Done correctly, you can really feel the difference and after a while, can do it with rudder feel alone given enough experience in the type aircraft. There is no sloppy side forces in the bank.

[Gooseneck]

There are no sloppy side forces in the bank.

 

Umm. The problem with virtual flying, is that the response of the aircraft versus input bears no relation to real life, because it is dependant on your own personal controller setup. A Saitek Cyborg will work and feel differently to a Logitech 3Dpro. With or without twistgrip rudder control.

 

A Thrustmaster Warthog with additional proprietary pedals will work differently to a Logitech G940 Hotas.

 

For instance, my rudder pedals are incredibly sensitive, such that I have to create a 5% deadzone in the 'Axis Tune' menu, followed by an adjustment to the sensitivity curve of 25%. That's with most DCS aircraft. I have no idea whether the rudder response I achieve by this is accurate for any aircraft.

 

The trouble is that we have no way of knowing how our own personal controller/game response relationship matches real life at all, in any computer game or simulation.

 

So how about giving us the benefit of your experience, tell us what controller setup you have, what your deadzone and curvature settings are, and how these relate to your experiences in real life?

 

This would be really helpful.

[Crumpp]

Crumpp says:

There are no sloppy side forces in the bank.

 

Refers to actual flying....

 

Dooyar says:

The problem with virtual flying, is that the response of the aircraft versus input bears no relation to real life,

 

Just use the correct amount of rudder input for your set up to keep the nose aligned with the longitudinal axis.

 

My controller is CH pedals, throttle, and combatstick. I just plugged them in and did not change any axis.

[Anatoli-Kagari9]

Hence, why I still think ALL pilots should start flying gliders :)

 

We do learn how to properly use the rudder for coordination :-)

[NeilWillis]

Agree. This completely dispels the myth of Douglas Bader being of any use at all. :)

 

 

Except of course he was fitted with artificial legs, and even played golf whilst wearing them, so not really a good point as I am certain he used the rudder pedals and flew with co-ordination.

 

Co-ordinated flight, and slipping are musts, so I echo the other comments - very good thread.

[Crumpp]

Hence, why I still think ALL pilots should start flying gliders :)

 

We do learn how to properly use the rudder for coordination :-)

 

Flying a glider will make you a better pilot.

[Cripple]

Except of course he was fitted with artificial legs, and even played golf whilst wearing them, so not really a good point as I am certain he used the rudder pedals and flew with co-ordination.

 

Co-ordinated flight, and slipping are musts, so I echo the other comments - very good thread.

 

OT: Actually, I've always wondered how he did so. Any ideas?

 

One can only assume that he had the trim cranked up to favour his "good" leg (the below-knee amputation) and rode that rudder pedal the whole time, if you follow me? I doubt his other leg (with the above-the-knee prosthesis) was much use in the cockpit as he'd have no "push" with it once strapped in. Oh, and if you wonder how he even got in to a Spitfire then see the attached pic. Yup, he got them to turn it sideways for him...:music_whistling:

 

(Back on topic) Am I missing something fundamental here, but I thought that the leading with the rudder in turns was part of basic flight training - either IRL or via booky-wooks?

[bongodriver]

rudder pedals sometimes had foot loops, it's possible to push and pull on a rudder pedal, maybe he used the better leg/prosthesis to do that, there is no denying Bader could use the rudder or he couldn't even taxy a Spit, you still need to operate the rudders to operate differential braking. I guess in theory it is still possible to push/pull on a pedal with an above knee prosthesis if you have enough leg stump to move.

 

Amazing achievement for this man to be a top scoring ace with 2 missing legs. not a pleasant man by some accounts but nevertheless a very inspiring one.

[NeilWillis]

Good question. I wonder if the information is out there somewhere?

[Crumpp]

Cripple says:

(Back on topic) Am I missing something fundamental here, but I thought that the leading with the rudder in turns was part of basic flight training - either IRL or via booky-wooks?

 

It is and also one of the most misunderstood controls on the airplane. In fact, I would even say more pilots DO NOT know how to properly use a rudder today compared with those who do.

 

Modern tricycle gear trainers do not teach you to properly use a rudder nor work to develop the muscle memory.

 

We’ve all heard it. “More right rudder!” is such a common command during flight training that some avionics company would probably make a lot of money producing a small device that could transmit the instruction at the push of a button.

 

Unfortunately, the training airplanes of today are so forgiving that they fly just fine without the proper use of rudder, at least as long as the flight attitude is somewhat stable.

Read more at http://www.flyingmag.com/blogs/flying-time/stay-your-feet#jePhY5dz3T9d7tMf.99

 

One of the more maddening aspects of instructing pilots who have already earned their certificate is continuous exposure to a rather curious dance in which their feet realize they are supposed to be doing something--but they neither hear the music, nor feel the rhythm. In other words, their feet are confused and don't know exactly what they are supposed be doing or when. Maybe it's time to examine the rudder's purpose in the greater scheme of flying.

 

A rule not to be violated: Whenever an aileron is deflected, there is unbalanced lift/drag on the wings and rudder is needed to offset the unwanted yaw. However, as soon as the bank angle is established, the ailerons should be neutralized, which means the rudder input is no longer needed. No aileron, no rudder. Period.

 

http://flighttraining.aopa.org/magazine/2005/December/200512_Features_Choose_to_fly_right.html

 

In a coordinated turn, the airplane’s nose should appear to stay in one place as the airplane rolls into or out of a bank.

 

http://www.jetairgroup.com/2013/03/19/how-to-make-coordinated-turns/

 

http://www.aopa.org/aopa-live?watch=hpa202YTpqZ-bn2yNikbfXO2iUdAZLbD#ooid=hpa202YTpqZ-bn2yNikbfXO2iUdAZLbD&ootime=08m30s

Edited October 16, 2015 by Crumpp