Use of rudder in turns

[DavidHoul52]

I have returned to Wolfgang Langewiesche's book "Stick and Rudder" after putting it aside for a while and have been pleasantly surprised to find some great information on turns. I had always thought - and I can't remember my FI correcting me - that one applied rudder throughout a turn in order to stop slipping. According to the author one should only use rudder when rolling in or out of a turn - while banked the aircraft does not need rudder and in fact use of the rudder causes it to descend and has to be compensated by excessive back pressure.

Moreover, the excessive back pressure can lead to the wing stalling and a resulting spin. This is especially noticeable in steep turns. I wondered why mine were always going haywire! If one centres the rudder when banked at the desired angle steep turns are easy.

Any comments?

[Johnm]

The purpose of the rudder is to keep the aircraft in balance, so if the ball is in the middle with the rudder neutral in a turn then so be it. That's situation normal in my Piper.

[Final 3 Greens]

David

Be aware that in some light aircraft (not all), the rudder is linked to the aileron and thus automatically feeds in when turning ,to "help" the pilot.

So it may not be obvious, but the rudder is being appled.

[Pace]

David

There is an RAF technique you can try. It involves using the rudder to initiate a turn and then applying aeleron to centre the ball.

It is very smooth and has the aircraft fully balanced in all axis in the turn.

Also when you have the aircraft trimmed for level flight and want to fly hands free try holding your heading by using the rudder pedals. That works too especially if you need your hand for maps books etc.

Pace

[DavidHoul52]

rudder is linked to the aileron


As far as I know none of the aircraft I have flown have this feature. (You can turn it on in Flight Sim though!)

According to the book it's sound aerodynamics. The rudder is only needed when banking not when banked (if you know what I mean). It makes sense if you think about steep turns - in fact the author says it might be a good idea to teach steep turns before shallow ones! It also goes on to say that turn coordination is primarily with aerelon and elevator back pressure.

[Tmbstory]

DavidHoul52:

The aim is to keep the aircraft in balance, that means the ball in the slip indicator should be centered in all normal flight.


Tmb

[DavidHoul52]

Ok - see what the ball does next time you do a steep turn. If the principle is sound then one can neutralise rudder every time without looking at the ball.

[bookworm]

According to the author one should only use rudder when rolling in or out of a turn - while banked the aircraft does not need rudder and in fact use of the rudder causes it to descend and has to be compensated by excessive back pressure.

Langewiesche has a habit of oversimplifying and then asserting the oversimplification as truth. Some regard this as evidence of his didactic brilliance, others as unhelpful dogma. You might notice the following footnote: "Important fine points regarding the handling of stick and rudder in a turn are disregarded here, in order to let the main idea appear more clearly."

The aeroplane will generally slip if held at a constant angle of bank in a turn with rudder central. It's the yawing effect of that slip through directional stability that causes the nose to yaw around the turn as the direction of motion over the ground changes. It's perfectly possible to operate an aeroplane in that way. If you want to fly the aircraft in balance, you need to apply some rudder to provide an alternative source of yawing moment.

[DavidHoul52]

Langewiesche has a habit of oversimplifying

Quite possibly - but I wish I'd known this when I did my skills test. I realise now that I have been fighting the rudder with back pressure. I would have realised this by watching the ball of course but one needs to be watching the horizon when doing steep turns.

There may need to be some rudder even so but I assume the point he is making is that it wouldn't be the same amount as when rolling into the turn.

[C172 Hawk XP]

That's situation normal in my Piper

Yep, same in our Cessna !

A very interesting discussion, though, and ideas which I'll be keen to try out the next time I "commit an aeronautical act" !

Won't be this weekend, though - - can hardly see out of the office window ! . . . . .:ugh:

[DavidHoul52]

Armchair flying only here too!

[Pace]

steep turns.
I realise now that I have been fighting the rudder with back pressure. I would have realised this by watching the ball of course but one needs to be watching the horizon when doing

David

I think you are oversimplifying all the forces involved in a turn and increasing bank.

In any turn around a radius the tendency for the aircraft will be to skid that will show in the turn and slip.

As you bank the rising wing will create more lift, the descending wing less lift that will mean that you will require more pitch to maintain level flight and with that extra pitch more drag.

Applying rudder in level flight will cause a yaw and the nose to turn around the centre of the axis of that yaw that itself will cause one wing to slow and the other to speed up again causing the aircraft to initially pitch up which followed by an increase in drag will then cause the aircraft to pitch down for a set level of power.

The forces are complicated and will take someone with a better description of the aerodynamics and complexity involved other than to say you need to keep all the forces in balance and the use of all your controls including power to maintain a smooth level steep turn.

Pace

[DavidHoul52]

As you bank the rising wing will create more lift, the descending wing less lift that will mean that you will require more pitch to maintain level flight and with that extra pitch more drag.

Applying rudder in level flight will cause a yaw and the nose to turn around the centre of the axis of that yaw that itself will cause one wing to slow and the other to speed up again causing the aircraft to initially pitch up which followed by an increase in drag will then cause the aircraft to pitch down for a set level of power.


Pace.

I'm with you in your first paragraph. L emphasizes the need for back pressure when turning - which we all know. Back pressure also stops slip (according to L.)

I don't quite follow your second para. Do you mean "level flight" as in "straight and level" or level flight in the turn? The nose will indeed turn around the centre of the axis of the yaw - but when the aircraft is banked at say 45 degrees that axis will also be at 45 degrees and the turn will be earthward. Thus the tendency for a steep turn to increase it's angle of bank and also descent.

That is my own summary of what L is saying and it makes sense from my own experience. Probably that is what you are saying but perhaps in a different way. As L would be the first to point out the aerodynamics are not that simple, but it does indicate what one would most often expect.

I think most would agree that a high angle of attack combined with a lot of rudder is not a good idea.

[Pace]

David

No I was referring in that part the effects of rudder only ie set up a level trimmed flight not a turn. Then with your hands off the control column apply rudder only and see for yourself what the aircraft does. Apply right rudder and then squeeze in left and note what happens to the aircraft in heading bank and pitch.

Then do the same apply aeleron only and again watch what happens.

Pace

[DavidHoul52]

Pace

Not flying today so can't give you an experiential answer.:{

I would say you will have yaw in both cases but in opposite directions. Back pressure will be needed in both cases eventually. L says that at slow speed the yaw in the case of banking only with the aerilon can be so severe as to cause the plane to turn in the opposite direction. Has anyone been able to verify that?

Obviously a coordinated turn is needed with both rudder and aerilon. But once the turn is established it's a different scenario. If one neutralises the aerilons at this point does it not make sense to neutralise the rudder too?

I'm not trying to be argumentative (although I like starting a lively discussion). It came as a sort of eureka moment as it explained a number of things I'd noticed while flying. Like why is the ball not where I expect it to be when turning? Why are my 45 degree steep turns suddenly becoming 60 degrees and more? Why am I loosing height? Why I am finding it so difficult to keep the plane level in a steep turn? Why do I need so much back pressure?

[Chuck Ellsworth]

In any flight attitude the rudder is used to keep the ball in the center if you wish to be in balanced flight....end of conversation.

[englishal]

The thing is, all aeroplanes are different....dihedral for starters.

I agree though, in simple terms when you roll into a turn you need *more* rudder - reason is that one aileron goes up, reducing AoA on one wing, one goes down increasing it on the other. Net result increase in drag on one wing and a yawing tendancy towards the downward ailerom. When you are IN the turn and ailerons are the same then this situation doesn't exist any more. Of course then you have other factors like outboard wing travelling faster, dihedral trying to level the plane, whatever......

One good exercise is to fly along S&L and rock the wings 30 deg either side and watch the nose. It scribes a circle in the sky. Now do it and apply rudder as you do and watch the nose stay still.....

[SNS3Guppy]

As far as I know none of the aircraft I have flown have this feature. (You can turn it on in Flight Sim though!)

According to the book it's sound aerodynamics. The rudder is only needed when banking not when banked (if you know what I mean). It makes sense if you think about steep turns - in fact the author says it might be a good idea to teach steep turns before shallow ones! It also goes on to say that turn coordination is primarily with aerelon and elevator back pressure.


David,

You may be surprised...rudder influence is brought to bear in various light airplanes through interconnect mechanisms of different types. You can usually see it by sitting on the ground and moving the ailerons...you should see the rudder move a little. Conversly, push the rudder a little without touching the stick or yoke, and on airplanes which have some interconnect, you'll often see the stick or yoke moving a little, too. This doesn't mean the airplane automatically "coordinates" for you...just that it's designed to give you a little help. Not all airplanes incorporate this in their design.

The amount of rudder needed in a turn depends on the nature of the turn, as well as the type of airplane. A steep turn has different rudder needs than a shallow turn. One type of airplane may require considerable rudder into or against the turn, whereas another may require little or none.

I'm flying a type right now that requires nearly no rudder input. Feet remain on the floor most of the time; the airplane does it all.

When I was younger and had just started doing ag work (crop dusting), found myself really fighting the airplane in the turns. We would pull up out of a field to clear power lines and trees, and make a steep turn right to the stall buffet, at 75 to 150' above the ground. I found that even though the airplane would be vibrating or buffeting, others could turn considerably tighter than me. I was white-knuckled on the stick, afraid that if I pulled it in any tighter, I'd stall and roll over into a spin. I was holding considerable bottom rudder because that's what I thought the airplane needed. It didn't feel right without it.

After a quick analysis by my boss, a very experienced ag aviator, he succinctly summed up my problem. "You're being stupid."

A more detailed analysis showed that if I used top rudder, as required, in the turn, it made all the difference. Once I tried it and got better at feeling my way around the turn, I discovered that I'd been slipping and skidding through turns. Suddenly I could go a lot tighter, reduce my turn times, and didn't get the rough stall burbles and snatches like I had. We still rode the airplane around the turn close to the stall, as it's part of that kind of a turn in that kind of work, but suddenly I was much safer, no longer putting myself close to a spin-under situation.

As Chuck noted, for a normal turn, keeping the inclinometer, or skid ball in the center of your instrument, is all you're really interested in doing. Whether it takes no rudder input, top rudder, bottom rudder...is really irrelevant. Do whatever is necessary with the control to make the airplane do what you need it to do. Your drag is reduced, your climb performance enhanced, your turn made more comfortable and smoother, and it's safer if you're slow (avoid getting slow).

A good exercise for developing a feel for coordinating your rudder input against other control inputs such as roll, is to practice making roll entries. Roll left to a bank of about 30 degrees, then roll right back to the right 30 degrees. Keep a constant roll rate going back and forth, and concentrate on keeping your skid ball in the center the whole time. Once you get comfortable with that, increase the bank to 45 degrees each way, keeping a constant roll going back and forth. You'll find that after a little practice you can vary the rate of roll and change the rate and amount by which you use the rudder to keep that ball centered. Once you've got that mastered, you'll understand normal use of the rudder, and can move on.

Remember that's normal use of the rudder. The rudder has many other uses too, aside from "coordinated" flight...but for now, and for the purposes of this discussion, keeping the ball in the center of your instrument means using whatever rudder input is necessary. That could be top rudder, bottom rudder, or no rudder at all. Typically because flights don't take place on perfectly smooth days and typically because none of us are perfect, keeping the ball in the center may mean small, smooth corrections involving top, bottom, and center rudder...much of the time. Use whatever is required to make the airplane do what you want it to do.

[RansS9]

Suggestion........google J.S.Denker "See How It Flies" .

"end of conversation"...I think not.

[Say again s l o w l y]

Blimey, this is one way of complicating one of the simplest things.

I couldn't care what a book says. Chuck has it nailed.

Don't overcomplicate things, unless you are designing the aircraft from scratch, just do whatever you need to do to make the a/c respond how you want it to.

Rocket science it ain't.

[DB6]

In simple terms - as has been stated - you DON'T need rudder once in the turn. You DO need it when rolling in and out of turns in order to counter adverse aileron yaw which occurs whenever the ailerons are deflected from the neutral position i.e. generating lift and therefore drag. Try it in a glider :eek:.
Maybe I should read Stick and Rudder again but I lost interest the first time after he called the elevators 'flippers' one too many times.

[bookworm]

It came as a sort of eureka moment as it explained a number of things I'd noticed while flying. Like why is the ball not where I expect it to be when turning? Why are my 45 degree steep turns suddenly becoming 60 degrees and more? Why am I loosing height? Why I am finding it so difficult to keep the plane level in a steep turn? Why do I need so much back pressure?

Don't blame the rudder for that.

Turns steepen because the outside (top) wing travels faster than the inside (bottom) wing. So there's a net rolling moment into the turn. If you don't hold out-of-turn aileron against that, your angle of bank will increase.

Once you have that angle of bank properly fixed, the next thing to concentrate on is the balanced flight -- non-slipping flight. That will (near enough) minimise the drag and therefore minimise the back pressure you need. The yaw budget in the turn has many contributions working in both directions. You will usually need into-turn rudder for the reason I described earlier, but there are other effects: if your out-of-turn aileron creates enough adverse yaw, you may actually find yourself skidding into the turn.

Different speeds and different angles of bank mean the various contributions net out differently. The only useful rule for minimising drag is "don't slip", which is almost equivalent to saying "keep the ball in the middle".

[SNS3Guppy]

you DON'T need rudder once in the turn.


Rudder may, or may not be needed in a turn. Often in a shallow turn, inside rudder, or rudder applied into the turn (also called "bottom rudder") may be required. In a steep turn, especially very steep turns, outside, or "top" rudder may be required. It really depends on the airplane and what's being done with it.

[BackPacker]

Turns steepen because the outside (top) wing travels faster than the inside (bottom) wing.

I've heard the same thing in a number of places and accepted it as gospel. But I just did the calculation for a PA-28 with a wingspan of 10.66 meters, doing a standard rate turn at 100 knots. I found that the radius of such a turn is 955 meters, so the speed difference between the wingtips is just a hair over 1.1%. Lift is not generated by the wingtips alone but by the whole wing so measured over the whole wing the speed difference, and therefore the lift difference, is more like 0.5%. I can't believe this is really responsible for the steepening of the turn.

Even in a 60 degree, 2g steep turn at 100 knots the radius of the turn is still 125 meters. This is still less than 5% speed difference between the wingtips, and maybe 2.5% speed/lift difference across the whole wing.

It would seem that even a little turbulence would have more impact than these low numbers. Any comments?

[RansS9]

"Blimey, this is one way of complicating one of the simplest things"

----It's not simple.


"I couldn't care what a book says. Chuck has it nailed."

---You should ...and he doesn't.

"Don't overcomplicate things, unless you are designing the aircraft from scratch, just do whatever you need to do to make the a/c respond how you want it to."

---They are complicated. How do you know what it is you need to "do" to make the aircraft respond the way you want? Intuition ?...say along the lines of slow speed, ground coming up, pull harder on the stick...type intuition.

"Rocket science it ain't."

---Science yes ...rockets...correct at no stage were rockets mentioned.

TIM

[bookworm]

I can't believe this is really responsible for the steepening of the turn.

Kudos to you for sanity-checking the numbers!

If you look at the very small amounts that the ailerons deflect in order to command relatively high roll rates, you'll see that even small differences in lift have a big effect in roll.

so the speed difference between the wingtips is just a hair over 1.1%.

OK, lift is proportional to speed squared, so that's about a 1% difference in lift at the midpoint of the wing. How do you think a 10 or 15 kg block of lead hung off one wingtip would feel in flight? How does your aircraft feel with a fuel imbalance?

[Piper.Classique]

L says that at slow speed the yaw in the case of banking only with the aerilon can be so severe as to cause the plane to turn in the opposite direction. Has anyone been able to verify that?

Yes, can be. Needs to be an aircraft with more than the usual amount of adverse yaw, probably without differential ailerons. Several older types of glider exhibit this behavior, the slingsby tutor for example. The greater the aspect ratio the more noticeable this is, usually. One microlight I have flown will do this, the X-Air, and probably others. Anyone fly a luscombe here, I seem to remember a fairish amount of adverse yaw? You do need to be flying pretty near the stall to make this happen, though.

Backpacker, quite right

Even in a 60 degree, 2g steep turn at 100 knots the radius of the turn is still 125 meters. This is still less than 5% speed difference between the wingtips, and maybe 2.5% speed/lift difference across the whole wing.

Think about the airflow on the whole a/c. Unless you have a banana shaped fuselage there will be a sideways lift on the fin and rudder and of course the fuselage, which will have far more effect than the tiny speed difference between the wings. A very small number squared is still a very small number:)

[SNS3Guppy]

I've heard the same thing in a number of places and accepted it as gospel. But I just did the calculation for a PA-28 with a wingspan of 10.66 meters, doing a standard rate turn at 100 knots. I found that the radius of such a turn is 955 meters, so the speed difference between the wingtips is just a hair over 1.1%. Lift is not generated by the wingtips alone but by the whole wing so measured over the whole wing the speed difference, and therefore the lift difference, is more like 0.5%. I can't believe this is really responsible for the steepening of the turn.


That's part of the equation, but the velocity is only part. While there may not be a huge airspeed difference between the outer wingtip and inner wingtip in a turn, there's a difference in the angle of attack. Additionally, the difference can be magnified in a descending or ascending turn, and is further altered when the airplane is not flown in a "coordinated" ball-in-the-center condition.

[bookworm]

While there may not be a huge airspeed difference between the outer wingtip and inner wingtip in a turn, there's a difference in the angle of attack.

I can accept that the AoA is modified in a climb or descent -- with all else equal, descending turns are more stable than climbing turns. Why would there be a difference in level flight?

[Gargleblaster]

... there's a difference in the angle of attack

SN3Guppy, could you explain ? This is something I've never understood !

I've done the same calculations re airspeed difference between the wings and concluded that flies, dirt, rivets, etc. would mean more than that.

The books normally state angle of attack is diffeent, but don't explain !

[SNS3Guppy]

I've done the same calculations re airspeed difference between the wings and concluded that flies, dirt, rivets, etc. would mean more than that.

The books normally state angle of attack is diffeent, but don't explain !


Angle of Attack varies as a vector with speed, and also with the upwash induced by the wing. Upwash is in turn variable with the wing configuration, airflow velocity over the wing, and angle of attack. Increase angle of attack, increase downwash behind the wing and upwash ahead of the wing, and angle of attack increases beyond the simple angle made by the free airstream and the wing chord line...local angle of attack is greater because of upwash.

Increase the airspeed over a wing or section of wing, increase lift, increase drag, and you also experience a change in AoA. Change the configuration of the wing, such as lowering an aileron, and with the mean aerodynamic chord change and effective camber change, you've got a change in upwash and downwash, as well as AoA.

Additionally, as the aircraft is rolled into our out of a turn, changes in local AoA vary with the rising or descending wing, and in a turn when some degree of spanwise flow occurs, changes in AoA follow, along with changes in the lift component of any given wing cross section at any given time.

A simple example of a change in AoA, and lift and drag can be seen by lowering an aileron. As the aileron lowers to raise the wing, effective camber is increased, drag increases and rudder may be required against the drag created by the aileron. This drag, adverse yaw, is part of the reason that rudder into the turn may be required when rolling into the turn. As lift is increased on the wing, drag is increased, and the wing is experiencing an increased AoA. This is one example of one reason AoA may be locally increased during a turn, or turn entry, or sustained in a turn...depending on the design and requirements of the specific airplane or wing in question.

Remember that the increase or decrease in lift and drag isn't linear, and varies with the wing planform...what one airplane sees as a big change under a given set of conditions (airspeed and bank) another airplane will see as a little change. Add numerous other variables ranging from airfoil to control positioning to dihedral to sweep, wing planform, and even center of gravity, etc...numerous factors come into play which affect the stability and habits of the airframe.

The following article contains a couple of tables and graphs using several different wing planforms which might give a little insight. You can see that the drag coefficients go both up and down, depending on what type of wing is in use, of several demonstrated in the computer modeling.

Drag in Circling Flight (http://ciurpita.tripod.com/rc/rcsd/drag2/drag2.html)

In a climbing or descending turn, the differences in AoA and the lift produced are a little more pronounced, and may be a little more noticable. One may not notice it in level flight, or the specific airplane may not require aileron into or against the bank...or it may only be noticable at certain degrees of bank, and not others. During a climbing turn, the outer wing tends to have a higher AoA, and during a descending turn it's the opposite.

-- with all else equal, descending turns are more stable than climbing turns.


They're not, though it may feel that way.

[DavidHoul52]

Don't blame the rudder for that.

Turns steepen because the outside (top) wing travels faster than the inside (bottom) wing.


That is true but rudder has a much greater effect. Try it on Flight Sim. Yes I know it's not 100% aerodynamically correct but it's pretty good on steep turns (I'm using the Cessna 152 from the Flying Club package).

Keeping an eye on the ball is obviously the way to go but knowing what to expect in a manoeuvre that has already a high workload is a great help, in my opinion.

Some interesting contributions here though. Thanks!

[SNS3Guppy]

David,

I'd caution you regarding microsoft flight simulator for learning about flying. While it can present some general benefits (push forward to go down, pull back to go up), it's not really a tool for better understanding how your airplane flies. Particularly where aerodynamics are involved. Simulators, even games like microsoft, are best used when experience in the airplane is transferred to the tool, rather than the simulation to the actual airplane.

Chuck was quite correct in his assessment earlier. We can talk about the finer points of why this or why that all we like, but the bottom line, and all you REALLY need to know is that the rudder is there to be used for whatever input is required to keep the ball in the center.

A steep turn is a confidence maneuver...it's something that as an instructor we have a student do to build confidence. It's not a high work load maneuver, and it's not a hard maneuver...which is why it's a confidence maneuver. It's a simple task which can be fairly easily mastered, which gives a student a sense of accomplishment prior to moving on to another task. It's also a useful demonstration of stability. In an airplane such as the Cessna 152, you should be able to set up the airplane in a steep turn, trim it off, and let it fly the steep turn hands-off.

[bookworm]

Angle of Attack varies as a vector with speed,

Not sure I understand what you mean by that. An angle is an angle, isn't it?

and also with the upwash induced by the wing. Upwash is in turn variable with the wing configuration, airflow velocity over the wing, and angle of attack. Increase angle of attack, increase downwash behind the wing and upwash ahead of the wing, and angle of attack increases beyond the simple angle made by the free airstream and the wing chord line...local angle of attack is greater because of upwash.

OK, so the changes you're talking about are in what you term "local" angle of attack, which includes the induced flow from the effects of the finite wing. So for the same downwash velocity, the induced AoA at the outer tip is less than at the inner tip because the forward velocity is greater? I can buy that, though I don't think that's a conventional use of "angle of attack", which is the angle to the freestream (before the aerofoil has had a chance to perturb it).

During a climbing turn, the outer wing tends to have a higher AoA, and during a descending turn it's the opposite.

Wouldn't you regard that as the climbing turn being "less stable"? A higher AoA at the outer wing tends to roll the aircraft into the turn. Conversely in a descending turn the higher AoA at the inner wing tends to roll it out of the turn. The turn may still be unstable because the total lift from the outer wing may still be higher, but it's more stable than the climbing case.

[bookworm]

That is true but rudder has a much greater effect.

But what exactly do you mean by that? That if you allow the aircraft to slip out of the turn by failing to keep the ball in the middle, the aircraft also tends to roll out of the turn? Yes, but that's the effect of the lateral stability (provided by dihedral or other stabilising effects) -- the aircraft wants to roll out of a slip. What the rudder is doing is eliminating the sideslip. That sideslip can indeed have a substantial impact about the roll axis.

[DavidHoul52]

But what exactly do you mean by that?

What I meant was if you continue to apply the same amount of rudder as when you rolled into the turn. That's all I'm getting at. I was previously keeping the same amount of rudder throughout the turn, neglecting to watch the ball because I didn't expect it to change (and had been never pointed out in training). As a number of posts here confirm this was incorrect. I just wonder how many low hour PPLs like me realise this?

I thought someone couldn't resist the chance to pontify on the misuse of Flight Sim! Yes I know all that. My point was that it's easily demonstrated in Flight Sim - I didn't "discover" it in Flight Sim. (doh)

I know those of you who have millions of hours can trim off a steep turn and show off going round in tight circles all day but for the rest of us it's still a challenge to keep absolutely level even though we have done it many times. Too much rudder when little or none is needed makes the exercise much more difficult and your confidence drops (as does the aircraft).

Also too much rudder means too much back pressure to compensate with accompanying high angle of attack. Little bit dangerous maybe?

I still think its a good thing to keep in mind and if you guys think its just foolishness I'll just keep it to myself thank you.

I think most of the posters here have missed the point entirely. But never mind...:sad:

[Say again s l o w l y]

"Blimey, this is one way of complicating one of the simplest things"

----It's not simple.


"I couldn't care what a book says. Chuck has it nailed."

---You should ...and he doesn't.

"Don't overcomplicate things, unless you are designing the aircraft from scratch, just do whatever you need to do to make the a/c respond how you want it to."

---They are complicated. How do you know what it is you need to "do" to make the aircraft respond the way you want? Intuition ?...say along the lines of slow speed, ground coming up, pull harder on the stick...type intuition.

"Rocket science it ain't."

---Science yes ...rockets...correct at no stage were rockets mentioned.

TIM

Getting an aircraft into, maintaining and getting out of a balanced turn is easy. If it is a problem, then someone has poor technique and was taught badly and/or has lazy feet.

When I'm flying I don't think about what the a/c is doing, I just move my hands and feet and magically the machine responds exactly how I want it to. That doesn't change whether I'm flying a helicopter, medium jet, aerobatic taildragger or simple spamcan.

I'm not always perfect, but going into enormous depth about the interrelation between controls is something I understand, but don't think about when I'm flying. I've been teaching it for years, but when flying things like "how much rudder do I need" should be automatic. I don't spend my life staring at the balance ball, after a while my patented inbuilt bumometer lets me know if the thing is in balance. Admittedly it can get confused when I've had a real hamfisted twonk whilst trying to teach them aeros, but 99.99% of the time it is fine.

Aircraft are simple. Pull back houses get smaller. Push forward they get bigger. If you push forward or backwards for long enough they get bigger and smaller of their own accord.....................

Making things overly complex for no real reason is a disease of many PPL's and inexperienced pilots. Don't make life difficult for yourself. Get up there and have fun, you'll soon find that discussions like this seem trivial.

[DavidHoul52]

I'm not always perfect, but going into enormous depth about the interrelation between controls is something I understand, but don't think about when I'm flying.


Exactly.

But your students might want to know why the ball is on the right when they are in a steep turn to the left, especially when they have been told to give left rudder when in a turn. Understanding that the rudder and aerilons go together is helpful I feel. No airelons then no need for rudder (in a turn that is)

To be honest, my FI didn't make much fuss of rudder either other than to occasionally point out that the aircraft was out of balance. And you are right - one feels it without even looking at the ball.

[RansS9]

Student is asked to make a steep level turn. Rolls into it but doesn't input quite enough backstick. Makes a quick glance at the balance ball sees it has dropped into the turn slightly and immediately inputs rudder to remedy it. Congratulations your in a balanced spiral dive. If all the pilot has been taught is "Stamp on the ball" then he's not going to be aware of other possible influences.

I agree wholeheartedly that things can be made overcomplicated and as a result confused. The control of the aircraft has to be almost automatic; but that automatism has to be grounded in good basic knowledge. However things can be dumbed down too much just leading to dumb pilots. I suppose it is all a matter of balance.

Getting the balance right; feeding ideas at a sensible rate; tailoring the instruction the the individual taking into account their interests and background. Like all the good things in life it's.. part art.. part science.

When I was younger I used to subscribe to the view; "those who can do those who can't teach". Not now.. a good teacher is priceless.

TIM

[DavidHoul52]

Another useful point made in L's book about steep turns is that if you haven't put in enough back pressure it's quicker and easier to regain pitch by rolling a couple of degrees out of the turn, then back pressure and then back to the desired angle.

Off thread - I see that the forum is now titled "The sheer pleasure of flight" which is a nice change.:D

[Final 3 Greens]

Making things overly complex for no real reason is a disease of many PPL's and inexperienced pilots. Don't make life difficult for yourself. Get up there and have fun, you'll soon find that discussions like this seem trivial

Sounds like good advice to me.

I've never been a natural pilot, but with an application of good training and plenty of practice, find that one can fly neatly by visual clues and seat of the pants.

Also, Like to look out when doing any turn, as you never know when a glider is coming the other way :}

[Chuck Ellsworth]

And you are right - one feels it without even looking at the ball.

In that case you are really miss using the rudder.

[vee-tail-1]

Whats the rudder for then?
My Robin ATL has rudder pedals which are used for taxying, but in flight they just serve as foot rests. No need for rudder in turns as the vee tail keeps the ball in the middle automatically. Must be something to do with a dihedral effect I guess. Rudder useful if needing to side slip however.

[Final 3 Greens]

In that case you are really miss using the rudder

Hey Chuck

Are you accusing David of being a girlie? :}

[Pace]

Whats the rudder for then?


loose an engine in a twin and you will soon know what the rudder is for :)

Pace

[DavidHoul52]

Quote:
In that case you are really miss using the rudder
Hey Chuck

Are you accusing David of being a girlie?


No, its the girl on ATC who gets me excited.

Hence my interest in the hands-off steep turn technique mentioned in a previous posting. The control tower would make a good central reference point. One hand would be needed to hold the binoculars.... :)

[Pilot DAR]

We use teh rudder to keep the ball in the middle (unless we are intending a slip/skid. Like cornering a car, it is really smooth to anticipate the need for application of control and apply that control in a measure appropriate to maintian control as desired. When you corner a car, you don't wait for it to drift across the centerline before steering, you steer a bit to anticipate the turn and then adjust accordingly.

Today while flying home in my mighty Cessna 150, I was playing at this. If I roll left and right 10 degrees either side of wings level, without touching the pedals, the ball will be 3/4 of a ball diameter out by the first cycle, and more than a whole ball out by the second cycle. If I roll from level to 30 degrees bank with no pedal, the ball will be 1 1/2 ball diameters out before I reach the 30 degree bank angle.

For this reason, as mentioned before, I lead my turns in all cases with pedal. It is noteworthy that my 150 is STOL kitted, so the ailerons are more effective, and the effective dihedral very slightly less. It's a "M" model, so it has the larges rudder of all 150's and is thesame as a 152 in this regard.

My observations of the day... Pilot DAR

[DavidHoul52]

For some reason many posters think what I got out of Wolfgang Langewiesche's book "Stick and Rudder" book was that one shouldn't use rudder at all when making a turn. This is what I wrote at the start of this thread:


According to the author one should ONLY USE rudder when ROLLING in or out of a turn - while BANKED the aircraft does not need rudder and in fact use of the rudder causes it to descend and has to be compensated by excessive back pressure.


I also always lead into a turn with rudder, not waiting for the ball to do as Pilot Dar has observed. Problem was that I thought the same amount of rudder was needed throughout the turn and as the song goes in Porgy and Bess "It ain't necessarily so".

I see that a bit further on in the book (I'm a slow reader) he has a section which he warns "students are forbidden to read" in which he says that it's not quite so simple and some planes will indeed need at least some rudder throughout the turn, but that in most cases forces cancel themselves so that for practical purposes one can assume that rudder is only needed when the airelons are not central (is that the right word?)

So far I haven't tried this out on an equally awesome Cessna 152.