RE: applying rudder?
 

myself i find it very difficult to turn during taxi without the use of rudder

kc

RE: applying rudder?
 

guess you've never sat in the seat of an Ercoupe??

kc

RE: applying rudder?
 

Sat in one? I took a flight in one @37 years ago in Michigan. Same guy owned 2 of them. Not impressed, and I wasn't even a licensed pilot yet. But I did understand planes.[:'(]

RE: applying rudder?
 

The problem with your comments, Mr. Agexpert is that this discussion is about turning, not aerobatics. You see a turn is a very specific manouver. Aturn is by design intended to change the heading and course of the aircraft for navigational purposes. Those examples you gave while they do change course and heading (for the most part. there are some exeptions like KE) they are really intended for thrills.
So when it is said that the rudder is not used to turn the A/C, again a four channel model or full scale, we are talking about when in the real world ATC says 'Cessna 3 5 sierra turn right heading 170...' or when in your model you make a TURN to final. Note I said turn not knife edge, not hover etc. etc. but a turn.

The rudder is required for all sorts of things like taxiing and certain aerobatics. it is not however used to turn the A/C in normal flight. The turn is accomplished via the horizontal component of lift (look it up) and not the rudder. In fact in most cases you cant turn using just the rudder all you can do is point the nose off center line thus making the plane crab or slip very handy for cross wind landings dont you think.

RE: applying rudder?
 

maybe you forgot in those 37 yrs that they had ailerons and rudder tied mechanically together to the stick and didn't have rudder peddles.......

on the comment about not to do it because one may need reversing, you can swap the control rod to the opposite side of the rudder and effectively reverse the servo direction.


that comment alone shows you know next to nothing about flight. any time you apply rudder it changes yaw of the aircraft ANDamazingly enough the thrust line changes by the same amount of yaw, it's called a flat turn, you can do flat turns (peddle turns if you're old school) via rudder only, and anytime you kick rudder it'll change the heading of the aircraft, in enough cross wind you'll side slip (indicated on the slip indicator) but you still 'turned' the aircraft, maybe they didn't teach you that in flight school and you're unable to grasp it hands on for some reason or another.......

kc

RE: applying rudder?
 

I didn't forget anything about it. It still didn't impress me. It was an awkward and poor flying plane, especially in a crosswind. Poor design, period. By the way, they don't have sticks. They use a control wheel. Maybe YOU forgot that?

RE: applying rudder?
 

now now all that and you misspoke too.

"Anytime you kick it'll change the heading of the Aircraft..."

now you know that isnt true. it won't happen every time. for example sometimes like in a cross wind your heading (the direction of travel) will stay the same. some times it is neccasary to use the rudder to hold heading.

I have never in full scale aviation been able to do a flat turn with rudder only. Rudder only will cause the wing to dip thus killing the flat turn. you will need some aileron input to hold wings level. rudder only will cause the plane to yaw, the yaw will result in the nose being pushed down. which could result in a spin.

RE: applying rudder?
 

You also don't need a crosswind to "slip" an airplane, it can be done in any wind condition including no wind. But I guess you were too busy trying to insult people to get your facts straight?

RE: applying rudder?
 

A slip is an aerodynamic state where an aircraft is moving sideways as well as forward relative to the oncoming airflow. In other words, for a conventional aircraft, the nose will not be pointing directly into the relative wind. Flying in a slip is aerodynamically inefficient and can also cause motion sickness in passengers. Inexperienced pilots will often enter slips unintentionally during turns by failing to coordinate the aircraft using the rudder; however there are common situations where a pilot may enter a slip deliberately by using opposite rudder and aileron inputs, most commonly in a landing approach at low power. Without a slip it is difficult to increase the steepness of the glide without adding significant speed. This excess speed can cause the aircraft to fly in ground effect for an extended period, perhaps running out of runway. In a slip much more drag is created, allowing the pilot to dissipate altitude without increasing airspeed, increasing the angle of descent (glide slope). Additional airspeed will further increase the steepness of descent.

Slips are especially useful when operating aircraft that have neither high-drag flaps nor spoilers (typically pre-1950s training aircraft), or in which the flaps cannot be extended due to a system failure.

Two forms are employed, the forward-slip and the sideslip. Aerodynamically these are identical once established, but are entered in different manners and will create different ground tracks and headings relative to those prior to entry. Slips are particularly useful in performing a short field landing over an obstacle (such as trees, or power lines), or to avoid an obstacle (such as a single tree on the extended centerline of the runway), and may be practiced as part of emergency landing procedures. These methods are also commonly employed in flying from farmstead or rough country airstrips where approach hazards are present.

The "relative wind" mentioned is caused by the flight of the plane and not WIND of nature.

RE: applying rudder?
 

heading is the direction that the aircraft's nose is pointing, indicated by the directional gyro or the compass. you're thinking relative heading.


never said you couldn't, simply responded to the comment that rudder is only used during crosswind landings, I've used side slipping many times on short fields to loose altitude without gaining airspeed.

kc

EDIT: having to refer to a dictionary for your flight information now bruce???

RE: applying rudder?
 

Nah, I just wanted to make sure even YOU would understand it.

RE: applying rudder?
 

I dont remember any one saying it was used ONLY in crosswind landings

RE: applying rudder?
 

There is some debate as to whether the Wright Bros were the first to fly, but one thing IS certain - Their plane flew better than anyone elses (Once other people HAD them) for one reason - Wing Warping

Everyone else tried to turn by using a rudder - they were thinking 2-dimensionally, like a car or boat. Flying is 3-dimensional.

It's basic aerodynamics. The control inputs needed to turn a plane depend a little on the plane in question (Eg. On a flat bottom winged plane, when rudder is applied, one wing moves faster than the other resulting in extra lift on that side and therefore a bank toward the other side - With a fully symmetrical wing, the bank is negligible)

So let's look at a Point-and-go type of plane (Fully symmetrical, goes where you point it)

Ok, you want to turn? You start by banking your wings.

Now, as gravity pulls the plane down, it "Slides" along the air in the direction of Arrow "A" (See Illustration)

To compesate, you add up elevator which wants to bring the plane in the direction of Arrow "B"

This results in a turn in the direction of "C"

So why use rudder? For the most part, with smaller glow models it's really not even needed in a turn - For that matter, it's rarely NEEDED even with bigger models or even full-scale planes. But more on that later.

The reason rudder is needed is that as the plane turns, the outer wing is moving faster than the inner wing. This creates more drag on that wing which results in a yaw to the opposite side of the turn (Right turn, plane yaws to left and vise versa). This is called "Adverse Yaw" and it creates excess drag. Rudder is applied in the direction of the turn to combat this yaw and keep the plane tracking smoothly through the turn. This is called a "Co-ordinated Turn"

Now as I said, on 40 - 60 size planes, you really don't NEED to coordinate your turns, but the bigger the plane, the more adverse yaw is created.

In a full-scale plane, an uncoordinated turn causes excess drag and can throw off your equilibrium resulting in air-sickness, so aside from avoiding the excess drag, it's nice not to have to clean up after your passengers :D

RE: applying rudder?
 

RE: applying rudder?
 

ok, agexpert,, you're my hero for that comment!! i needed a good chuckle...

...OF COURSE YOU USE RUDDER TO TURN....

and that's the beautiful thing about this hobby, if you don't wanna use rudder to turn, you don't have to.

RE: applying rudder?
 

You do if it's a 3 channel w/o ailerons.

RE: applying rudder?
 

But as Minnflyer stated, You do not need rudder to turn (other than three channel) obviously if you dont NEED it then the rudder doesnt cause it. it only makes it more comfortable for passengers and makes it look prettier.

RE: applying rudder?
 

UM..you're right, my bad. What color is your pocket-protector?

Thanks for setting us all straight on exactly what this discussion is all about. Sorry for being out of line...or is that 'circle'? I was unaware of the fact that rudders are a comlpetely unnecessary airplane appendage. I guess we should ban up-lines too as they are not a part of normal flight for a full scale Cessna.


OH...and um....(YAWN).

RE: applying rudder?
 

Where did I say that the rudder was an unnecessary appendage??

In fact the quote you yourself provided lists some legitimate uses for it. Other posts in this thread by myself and others will tell you exactly what use the rudder is on an airplane, both full scale and on models. What you will find missing however is where the rudder is used to CAUSE the turn. What you will find is where others have said that it makes the turn more comfortable for passengers. This is of course not relevent in models. I know you will dissagree with me on principle, however perhaps you might be interested in reading some of the other responces that do in fact agree with me, and have said the same things that I have said.

As for the color of my pocket protector, I don't have one. But I do know a rudder is used for and what its not used for. As you being out of line, Hey man don'y worry about, I would just like to say that through this discussion that you are the one that has taken it to a personal level with the insults and back handed comments and as such I would say that yes Sir, you are in fact out of line. But again don't worry about it.

"Out of circle" is that supposed to mean that you think that I will argue about a geometric shape?? Well sir, again I know what a rudder is and isn't used for. Causing a turn it is not used for. Initiating slip it is, countering adverse yaw it is.

And speaking of the Wright Bros. how ever did they perfect the airplane without a rudder to steer with?? Or is it that the principles of flight and aerodynamics have changed. If you say they have then I would say that you are argueing for the circle.

RE: applying rudder?
 

This is just plain funny.

Sorry, I didn't mean to get under your skin, but it sure was EASY. Tell you what, you continue to fly with a little rudder as possible...even no rudder at all. I will continue to use copious amounts of rudder whenever I want. Then again, I don't much enjoy watching paint dry either. Everyone has their own way of doing things.

I am happy to hear that you know what rudder is and is not used for. That was previously unclear.

Enjoy the hobby, I do.

RE: applying rudder?
 

Please resist the urge to curse, flame, degrade, insult or embarrass someone in your post. We encourage the free flow of your ideas, but believe that they can be communicated (and received) much more effectively if you keep things civil. If you have to vent, take it offline. We carefully monitor posts and will ban individuals who engage in offensive conduct within the forums. Thanks. (RCU Policies)...Some so called self proclaimed "expert" should take note. When "newbies" ask questions does it make some feel good to degrade anybody who disagrees with them. No wonder people refrain from asking "silly" questions...be proud..."Expert"

RE: applying rudder?
 

LOL

One post and you have already demonstrated the proper use of 'cut and paste' as well as a startling lack of understanding. I did not curse, flame or degrade anyone. But you just had to register and take a shot at me for defending my position that using rudder is in fact better than not using rudder when flying TOY airplanes. That is my point, don't get all weepy about it and get your feelings hurt.

I am sorry if my sarcasm is too much for you to bear reading without feeling the urgent need to respond to a thread that was just about completely played-out.


Carefully consider your breathless response to this post as you, Mr. one-post, are one of two things: 1) New to posting in RCU forums, (and in that case, Welcome. Livley discussions are part of a healthy website). 2) A coward who registered under a new name in order to make a 'drive-by' post. Either way, keep in mind that the word 'offensive' is subjective. Just because you don't like someone has to say does not make it 'offensive'. If sarcasm is offensive to you, even when you are not really involved in the discussion, then perhaps it is not the sarcasm that is the problem.

Just to clarify; AGexpert is indeed what I am. It is my job, my livelyhood; I am respected in my industry for it and people pay me to be an AGexpert. That is what I do. I did not 'self-proclaim' anything. The people who depend on my expertise for their livelhood did that. Take it up with them. They are my friends.

Now, please move along and find some way to CONTRIBUTE to a discussion, not criticize a single poster for the way in which he attempts to convey useful information to others.

Rudder is a useful and fun part of RC flying, that is the point I am defending. If you don't want to use rudder, by all means do not. Thy are indeed YOUR toys to play with as you see fit. I think anyone who refrains from using rudder is missing-out on a lot of FUN with their expensive models. These are toys. There are no passengers. Any comparison to REAL full scale airplanes with passengers is simply ludicrous and deserving of some measure of derision. Nobody dies in TOY crashes....well, almost nobody.


Thanks for giving me something to do while I travel for work as an AGexpert, Einstein.

RE: applying rudder?
 

Ok, guys, since the question has been adequately answered and now it's just getting into a debate, I'm going to close this thread.