acdii

So far I really havent needed to use rudder on takeoff with my planes, except to keep it straight, but the 4*120 seems to need it. Which way do I need to feed in rudder on take off, I keep doing it wrong for some reason. Is it right rudder as I power up? Should I apply any aileron? My other planes aren't very torquey on takeoff, but I noticed this one is from the few run ups I did, but I keep veering off, it was in the opposite direction that I am used to for taking off and landing, so when it went left I made it go more left. I had this engine and prop on another plane, but it didnt veer as much as the 4* does, it was also much longer in the fuse, and had a shorter wing and chord.

GarySS

My Feedback: (13)

Push the rudder to the right to counteract the torque of the propeller. I've had to do this with a 60 size Super Sporster, and currently with a Phoenix Strega. Sometimes it is significant right rudder, but you should eventually develop a feel for the amount.............with slowly letting it back off as you lift from the ground. I'm not considering any cross winds, but the torque effect remains dominate in most cases.

Top_Gunn

My Feedback: (6)

You need to apply rudder in whichever direction will keep it going straight. If you can't do that, you shouldn't be flying a 4-star. It's usually right, but some planes are different, and a crosswind can make a difference when it's on the ground.

acdii

I thought it was right. I'm just not used to taking off from right to left and I was all out of wack.   On the Kadet I dont need rudder to take off unless there is a crosswind.  For that matte, I did have cross winds and turbulence when I was trying to take off, and I think all three combined, along with first flight jitters just had me all messed up.  The engine quitting twice just before turning to line up, was a good sign, the plane was talking to me. 

Scirocco14

When I teach new flyers, especially with taildraggers like Cubs, I have them practice taxiing up and down the CENTER of the runway. Usually applying slight up elevator to keep from tipping over, and learning to use the rudder to keep it going straight. At first, the new pilot is REACTIVE and trying to keep up with the plane veering one way or another. Eventually it becomes intuitive and they ANTICIPATE what the plane is going to do and apply the correction almost before it's needed.

If they can't taxi down the center of the runway without veering off to one side or another, they're not ready to take-off yet IMHO. The point of this exercise is to NOTtake-off until the pilot can proficiently keep the plane going down the center of the runway, under control, up to take-off speed.

We slowly increase the taxiing speed, one click of the throttle at a time, until they can taxi down the center from one end to the other.

When they're ready and can do that, a couple more clicks of throttle and they're in the air.

Try it, it might work for you!

Mark

PS 85% of the "experienced" flyers at my club can't do this. My students can.

Charlie P.

First verify three things.  With the rudder centered if you push the aircraft on a smooth, lever surface (i.e. driveway) does it track straight?  Adjust the tailwheel until it does.  Second - is the plane balanced laterally?  It should hang level from the propshaft and rudder hingeline.  Add weight to the high wing (I pull the servo and tape cents or sheet lead to it with black electrical tape as needed).  You can also drill holes in the tips and epoxy finishing nails in them.  Adding a few degrees of toe-in also works wonders and I do it as a matter of course when assembling the gear.  Lastly, make sure both wheels spoin freely. 

Also note - a cracked wheel pant works like a brake shoe on grass.  I had one model that developed an inability to take off.  Turned out both wheel pants had cracked and the grass pushed them against the wheels - instant brakes.  Now I remove them unless the model shows it accepts them well on grass.  I have 1.20 size models that don't and .40 size that do, so it's not entirely wheel size related.

If these are OK - then give right rudder as needed to counteract p-force & torque.  Stay off the aileron unless a wing is lifting.

acdii

I have no problems going down the center, from left to right, its the right to left that gets me screwed up. Still working on it.  Also taxi on a grass field that isnt very smooth is a handful.  The only thing not used to yet is the torque from the motor on the 4*, it caught me by surprise since I didn't have that problem on the Dewey with the same engine.   Add in the crosswind and turbulence coming over the roof of the barn and it was overload of the coordination. 

Top_Gunn

My Feedback: (6)

This is something you can work on any time. Just sit on a chair, holding a transmitter, and picture the plane going in one direction, then veering right or left. Then apply rudder in whichever direction you need for the correction. Fifteen minutes of that and you shouldn't have a problem with the real thing,

Sorry if my earlier post seemed somewhat abrupt. We all (well almost all) had these problems starting out. The one thing you definitely don't want to do is to start flying only when you can do it in the "easy" direction. I've known guys who have been flying for years and can only turn one way (usually left).

jester_s1

It sounds like you just weren't used to the wind you were flying in, coupled with going from a trike gear to a taildragger. For setup help though, in addition to making sure it tracks straight with the tailwheel also make sure that both main gear wheels are at the same angle with the centerline of the fuselage. It is possible to have a crooked main gear and still track straight because you've adjusted the tail wheel to compensate. The problem with that is when the tail lifts the plane will suddenly veer to one side because you've taken away the correction of the tail wheel.

In calm air or straight down the runway wind, a taildragger should track straight in low throttle with no correction. Then as you increase the throttle, there should be a second or two of left yaw that ends as the plane builds enough airspeed for the rudder to start working. Then when you rotate to take off you should get a slight left yaw again as the P-factor increases for just an instant. So a takeoff with a tail dragger in favorable wind conditions should be taxi straight, increase throttle and add right rudder, release right rudder, build speed, pull back elevator and give right rudder simultaneously, then release both together to fly out straight.

CGRetired

My Feedback: (1)

The way I learne, and eventually taught others is this:

Do large and slow figure eights at a pretty good height (three mistakes high is what we usually say). The height gives you time to realize what might be going wrong and correct it. The repetitive action g gives you equal time with left and right turns. Focus on the turn and keeping the plane level during the turns. Point the antenna in the relative direction of the aircraft travel.

Once you get "tuned" into the turns, you will most likely start keeping the antenna pointed in one direction with the turns coming at you as quite normal and automatic.

CGr.

acdii

Thanks, this made the most sense to me. My Kadet is a tail dragger, and tracks straight, I just never notice any yaw in it unless there is a cross wind. I think the tracking on the 4* is off, it wants to go right on the ground so I have to compensate with left rudder. So my guess is that is what I was having trouble with. I was applying left to keep it straight and as soon as the tail lifted, the left kicked in big time, because that is what was happeneing, it was coming right for us, and the cross wind was from behind us, pushing the tail away, causing it to come left even more, but happened too fast for my brain to react, so I aborted.

I will follow several of th etips here and take the plane back to the shop and check everything out once more before I try again. I'll bet its the ground tracking that messed me up, I can fly this bugger on the Sim with 16 MPH winds out of the southwest with me facing north, just the same as it was when I tried to fly the real thing. The winds were only at 10 when I tried. Funny thing is, in the air, I have no problems controlling direction with the rudder, no matter which direction I fly, only on the ground am I having a problem. I have gotten pretty good lining up to land in either direction now, and do T&G both ways. But dang if I didn't have problems trying to take off the other day.


One other thing I thought of, our field is very narrow, not a lot of room to work with, and there are obstacles on all sides, like corn on 3 sides, a couple warbirds against the barn, and us. Whiles its a good place to fly, you dont have much room on the ground for mistakes.

jester_s1

I think you have it right. If you need left rudder on a takeoff (aside from handling crosswinds) then your wheels are on crooked.

acdii

Thanks, sometimes I need to talk it out to figure out what I was doing wrong. Makes total sense now why I was having problems.

acdii

Well, I got the plane on the bench, that tail wheel was way off, it didn't start out in that direction, looks like the set screw was loose. Made some adjustments and looks like it tracks straight now. Hopefully that was what my problem was, thanks for the tips.

Gray Beard

My Feedback: (-1)

In post 5 Mark stated most people can't keep a plane straight on the runway, that's very true and sometimes I don't even want to be on the flight line after some of the guys have landed. If they would just practice. Mark mentioned the CUB, perhaps one of the hardest common planes there is to steer on the ground but it's the narrow gear and extra long wing, they take a lot of practice.
As beginners we will go with the engine torque factor but the left drift is caused by a thing called the P-factor, the vortex from the prop reacting on the rudder and elevator but for now it's the engine torque.
Up elevator is a must to hold the tail wheel down but something most new pilots don't do, it's tricky to know when to release the elevator before the plane starts to lift too early and stall.
The left to right and right to left is very normal too. At events I have met pilots that just couldn't take off or land due to the wind direction at our field. When I learned to fly I was flying off of two fields and they were opposite of each other. When I was going to fly an IMAA event though and the wind direction was different then my normal field then the trick was I would just shoot approaches in the direction the events field was going to be, that worked well.
Another trick is to take off and land while you are standing on the other side of the runway. My club has marked pilot boxes on both sides. That works great and it's what we did for people that couldn't take off and land from the opposite direction of there home field.
As Mark said, it's just a mater of practice. That and making sure your steering system is nice and tight on your airplane.
I have planes with just skids, they work pretty well on a soft field but what a thrill on hard packed!!

j.duncker

My Feedback: (2)

Some people have been known to cheat and put a gyro on the rudder. Easy peasy to keep it on the line then.

GWS 3 Hobby King $24

jaka

Hi!
As Charlie P says. Most of the time it's not torque, many times it's just the wheels that isn't adjusted right. See to that you have the landing gear with the wheels mounted with a little toe-in and a little chamber.

acdii

I don't have problems taxiing on the center line in either direction, it was the taking off that got me screwed up, and hopefully now that I have the tail wheel tracking right, taking off wont be such a problem. Something tells me I would have had issues no matter which direction I was going once the tail wheel came off the ground.  Tomorrow I am retrying after doing a little more carb tuning to richen it up.  

acdii

Thanks for the help on this one. The torque isnt bad on the 4* as it was on the Dewey, but man the P Factor is crazy on it. It took me by surprise at how much rudder I needed once the tail lifted.

A few more flights and I will have it nailed, its hard the first couple flights when you only have about 30-40 feet of width to take off from. I dont even think there is that much room when you factor in where I stand, and the plane parts and forklift also in that span of area. I think it is more like 25 feet wide, with 6 feet of corn on three sides.

jester_s1

You actually shouldn't see much P-factor once the tail is up. It's when the nose is up and the plane is going straight that P-factor really bothers you. That happens just as you power up and then again when you rotate to take off. If the thing is still squirrely after you have the wheels on straight, try a taller tail wheel. The less rotation you have to do to get up to straight flight the less the torque and P-factor can mess with you.

HighPlains

My Feedback: (1)

I suspect that you need slightly more right thrust on the engine.

Often one has to take off with a cross wind. To to that well requires the coordinated use of ailerons along with the other primary flight controls. Don't cheat by crossing the runway into the wind. Actually learn how to master the airplane.

acdii

That was it. I wasnt expecting it to pull left as much as it did, just as the tail wheel left the ground, and since its a new to me plane, didn't know just how much rudder is needed, so the first takeoff was ugly. Once I saw how it handled, the second one was nice and straight. I was taking off straight east with a north east wind, so had the cross wind, and turbulance of coming over the top of the corn. It is also a much larger plane than I am used to, so judgement of distance played a factor in the first take off, thought I had more room on the left than I did. 2 feet and it would not have touched the corn. Unlike the Dewey, the plane didnt want to roll left, so the engine torque didn't play a factor in that I thought it would, which I was expecting. It took off nice and level, and swung its nose to the left just as it reached the 6 foot mark where the tops of the corn were. I was ready for it the second time, and it was a real joy to fly.

It handled so much better than the Kadet once off the ground, for once I can take my hand off the stick and not worry if the plane would roll or something else. The size and weight, and that huge wing, really make it stable. The Kadet has half the wing, with the same dihedral, so little upsets in the wind can knock it around, but thats fine since it is a bit sportier than the standard Kadet. It was my first tail dragger, I converted it from the plans when I built it so I could learn how to fly one, I dont like trikes too much. When taking off in the Kadet, I rarely ever go over half throttle, unless it was really hot out, which was only once, so P Factor really never reared its ugly head on that plane, it takes off so smooth that I barely have to touch the rudder, I just throttle up, make any minor correction to keep it lined up, unless theres a cross wind, then its rudder and ailerons to keep it straight, ease off on the up to where its just a tad up, tail comes up, then the whole plane just lifts off nice and smooth, some times I get it off in 10 feet if the wind is strong and right out of the east or west.

Thanks again for the tips, it really paid off to know what to expect, I wasnt caught too much by surprise on the first take off, just in the fact that it left the ground much quicker than I thought it would, so that with the left pull, gave me a moment of WOW< then the corn jumped into its way at the last instant. 2 feet, thats all I needed to have kept it from touching the corn. I know now to keep it closer to me when taking off, its a big sucker.

jaka

Hi!
Have you checked if you got wash-out in a wing tip?
I nearly got that impression when you describe how it reacts when you take off.

acdii

well I hope they did it when the built it. It's an ARF 4*.  Once off the ground it flies great. First flight jitters didn't help along with the 3 walls of corn surrounding the field.  For all I know its doing exactly what its supposed to do.  Rudder control overall is good, it drops the nose when I make a turn using the rudder, more than the Kadet does. I just needed 2 clicks right aileron to get it level, no up or down trim, no rudder trim. It pays to follow the book and do each step right.

KitBuilder

I thought the right rudder was also needed due to the corkscrew of air from the prop over the vertical stab as well until enough speed is attained so it can do its job.