Zandona

Ok here I go again. I've been reading some posts and I've realized that some guys are able to pull barrell rolls with rudder/elevator planes [X(]. I was wondering how can that be done. A loop is totally understandable, even inverted flight I can imagine but don't you need airelons to do that?[sm=confused.gif][sm=confused.gif]

Hossfly

3-channel airplanes use rudder for rolling the airplane around the lateral axis. If the airplane will roll -- bank -- with the rudder, then why should it not be able to do any roll that the pilot asks?

The Barrel roll is the easier. More axial rolls require a much more skillful touch on the controls. Just remember that when an airplane is flying level in unaccelerated flight, the vertical lift of the wing is equal to the vertical component of gravity. When the pilot rolls the machine the vertical wing-lift vector is no longer opposite to the vertical gravity vector. Therefore wing loading must be altered, normally by elevator inputs which reduce the wing loading thus reducing the lift vector. If not, the nose, she will point downward with both vectors pulling that direction.[X(]

The machine knows not what is causing the roll and only reacts to those inputs of the pilot. Someone else can relate the use of rudder for roll. You can do wonders with a 3-channel model. Heck there was a time when they did wonders with ONE channel.

dreadnaut

My Feedback: (5)

Lots of rudder

Zandona

Hossfly, what you have said makes total sense but whenever I try all I get is a tight turn [:@]. Maybe I'm going too slow (my plane is not that fast anyway) or maybe I'm not feeding enough rudder. I'll keep trying and hopefully I'll get soon.

siclick33

You may need to increase the throw of your rudder and flying faster will help too. Bear in mind though that some models just dont want to do it.

If you do try make sure you have loads of height. If you get inverted and the roll rate is too slow you may have to pull through. This is normally a bad idea as you lose loads of height and the aircraft speed will increase significantly.

Once you have found that it works at height then you can try it a little lower.

Have fun!

ksechler

It's simple. Get 3 mistakes high. Pull the nose up a little and then put in full rudder. As the plane rolls to 90 degrees start pushing in down elevator. Keep pushing the down elevator through inverted until the plane is 90 degrees again. Then start to pull a little. It's not always pretty, but it'll work.

Red B.

In order to get a better picture of what a barrel roll looks like imagine flying a corkscrew loop. It should look like one turn of a very elongated coil-spring (figure below). Although the previous postings indicated how to perform the barrel roll, because each aircraft behaves very differently, you will have to work out the exact control inputs by yourself.
When I learned to perfom it I started out by trying to make my loops looking more and more like corkscrews. You will find that in order for the barrel roll to look nice you will have to alter the control inputs during the maneuver.

/Red B.

Ed_Moorman

My Feedback: (1)

Zandona,

First, it appears you want to know how to do a roll with a 3-channel airplane. Planes that steer with rudder are generally high wing with dihedral. Both the wing location on top of the fuselage and dihedral will cause roll in the direction of the rudder when it is applied. We call this "roll due to yaw."

Visualize your plane flying through the air. You put in and hold right rudder. This causes the plane to yaw so the airflow hits the left side of the fuselage. The airflow splits to go around the fuselage. The air going around the top of the fuselage hits the underside of the wing causing a roll to the right.

Next, visualize a wing with a lot of dihedral. Yaw it to the right. The air flow now hits the top of the right panel and the bottom of the left panel, both causing roll to the right.

The combination of these 2 will give a pretty good roll in many planes.

Second, you mention a "barrel roll." A barrel roll is a specific maneuver that is a spiral rather than an axial, or aileron, roll. Rudder only planes tend to do barrel rolls naturally rather than axial rolls, which aileron planes do very well. Doing a barrel roll with an aileron plane requires you to hold a slight amount of elevator during the maneuver to get the spiral rather than a roll around the longitudinal axis of the plane.

To do a roll with a rudder plane. Go to full power. Raise the nose 15-20 degrees and release all the up elevator. Put in full roll control and hold until the roll is complete. Recover from the slight dive. This roll is best done "by-the-numbers," step by step without any mixing of the controls. Raise the nose, release, roll, release, up to recover, release.

Montague

The more rudder throw, the better. Also, more dihedral helps with rolling. Moving the CG back makes it roll better as well (makes the whole plane touchy).

You ain't seen rudder flying until you've seen a rudder-elevator combat ship mixing it up with the aileron-elevator ships. I gotta tell you, rudder ships are REALLY hard to catch, I usually leave them alone and go after someone else .

Jeepindog

Interesting observations of airflow splitting around the fuse and hitting either the top or bottom of a wing panel... Anyway, when a flyer commands rudder (right or left) on a plane with a flat bottom airfoil and some degree of dihedral, the yawing action actaully causes one wing to increase in airspeed slightly, and generate more lift, as the rudder pushes the tail of the plane to one side. These two actions together will typically cause a trainer type plane to bank and initiate a turn. One must also usually pull on the elevator to push the tail around in the corner. It can also be seen, typically to less extent, in symmetrical airfoils as well.

Lachlan

Jeepindog

Interesting observations of airflow splitting around the fuse and hitting either the top or bottom of a wing panel... Anyway, when a flyer commands rudder (right or left) on a plane with a flat bottom airfoil and some degree of dihedral, the yawing action actually causes one wing to increase in airspeed slightly, and generate more lift, as the rudder pushes the tail of the plane to one side. These two actions together will typically cause a trainer type plane to bank and initiate a turn. One must also usually pull on the elevator to push the tail around in the corner. It can also be seen, often to less extent, in symmetrical airfoils as well.

Lachlan

Zandona

Wow you guys are awesome I'm surprised with all the help thanks a lot . Now that I've been introduced to some of the theory behind this maneuver I'll give it a try again this weekend, after this short "barell roll aerodynamics 101 course" I think I can make it. One more thing though do you guys know if there is any site with some good acrobatic videos?

MikeMc

Try flying inverted next.

Jim Finn

My Feedback: (2)

The title of this thread talks about 3 channel planes doing rolls. I do them very easily with 3 channels. No rudder. ....... Aileron, elevator and throttle. 3 channels.

Montague

Yes, but can you stall turn/hammerhead?

(actually, I fly my aileron-elevator combat planes around and do things like stall turns, "kiting" in a headwind, snaprolls and spins, etc all with out the rudder. Doable, but the rudder makes it more fun. Stall turns are the hard to do consistantly with out a rudder)

BrightGarden

Great thread although 11 years old. I was able to learn how to roll in RealFlight 7 tonight in about an hour after reading this old thread.
It was a lot of fun once I started figuring it out. At first I couldn't tie the advice above to what to do but I just kept trying things and it finally clicked.
I used about 3 or 4 different planes in RF7 and each behaved differently, cool. Some just wouldn't start rolling, were too stable.
Big dihedral made the rolls loopy.
I was getting it down after an hour or two where I could occasionally get a tight roll.
Found you had to develop some finesse to not just slam down elevator at the 90 degree roll mark. I found pumping the down elevator lead me to realize how much to actually use - at first, just pulse the down elevator and I think it will become obvious when to apply and when to ease. Gave me a sense of appreciation of what the air show pilots in the airplane are doing. So now I have loops, snap rolls, flat turns, a little knife edge and barrel rolls down. What next?
Cheers and CAVU

Gray Beard

My Feedback: (-1)

When I saw Ed Moorman posting I looked at the date. Ed still posts once in a while. I was a student of the Ed Moorman stunt flying years ago. He wrote for RC Report, at the time it was the best magazine still in print, now no longer with us.
I love three channel planes and have set them up differently over the years. I found the single stick for rudder and elevator the easiest for me, but have set them up with the rudder and throttle on the left and the elevator on the right. My problem with that is I have to think about the inputs when flying.
The barrel roll is easy just by pointing the plane up about 20 degrees then giving it rudder and elevator.
If you can, try to find someone with all of Ed Moormans stunt of the month cut outs. I have most of them and have given a copy to my students in the past. Ed makes all the stunts easy to understand and showed the stick inputs.
I was after Ed to write a book on not only stunts but plane set up for a number of years but have never seen it happen. He made it a lot simpler and spoke in a way everyone could understand. Sure miss RC Report but it had to start turning into a book of ARFs like the other magazines, just a sign of the times but it was still the best we had from the U.S.A.