I just purchased a GP Super Decathlon kit. I have been reading threads on this plane. Tip stall is mentioned in regards to this plane and others. It is suggested that "washout" be added when building the kit. I know what that is, but WHAT IS TIP STALL? Is that when the wing loses lift with the tip losing lift last and thus the wing falls?

I am a beginner, this will be my first kit. I would appreciate your answers.

Thanks
Jim

This is a simple explanation: The stall occurs at a wing tip first. This can result in loss of control and a sudden drop of one wing, which results in a spin. It is best to design wings so that the root stalls first and the tips last so that the ailerons remain effective until the wing is almost fully stalled.

Please note this is also PLAGARISM!!!

Welcome aboard, Jim.

I know your question is about Tip Stall, but let's talk about your SuperD for a minute. This plane has the capability to leap off the ground before it is ready to fly. At that point, it will stall, drop a wing, hit the ground and cartwheel. Washout will not cure this type stall, so it is important to understand the process for taking off.

To avoid : Do not hold up elevator during the takeoff roll, after the plane starts moving! Release the elevator, steer with the rudder, and let the tail come up. Add only enough elevator as necessary to keep from nosing over - and only if necessary! Continue the takeoff roll, letting the plane build plenty of speed before adding minimal elevator for a lift-off and shallow climb-out.

Once in the air, you'll notice that at too slow a speed the plane will sort of fall nose down in a stall, rather than drop a wing. That's because it has washout. The wing tip is the last part of the wing to stall.

Enjoy your SuperD!
Dave Olson

Once in the air, you'll notice that at too slow a speed the plane will sort of fall nose down in a stall, rather than drop a wing. That's because it has washout. The wing tip is the last part of the wing to stall.

Scar: Based on the above statement, you believe I should as washout when building the kit even tho you state in your first paragraph that "washout will not cure this type of stall." Exactly, what is the purpose of adding washout, particularly for this plane.

I really appreciate you thoughts and suggestions. I won't be flying this plane for sometime. I have not yet soloed. I purchased a Hangar 9 Alpha 60. On my first flight
with an instructor using the buddy box I was mid aired. I am currently rebuilding that plane but I have purcased another one. I am waiting for some time with an instructor. Needless to say, I haven't soled on the trainer, yet. But, I will have several months in building the Decathlon so in the meantime I intend to get in a lot of training.
By your response, I am assuming you have experience with the Super Decathalon. What is it like to fly it?

Thanks
Jim Vines Jr.

Jim,

Dave's description is excellent. Many people look at this style of plane and see the high wing and think it is basically the same as a trainer. Then they try to fly one and find they are much more difficult. I have a Great Planes Cub that has these exact same traits. Once in the air this style plane isn't all that difficult to fly. The takeoffs and landings, on the other hand, can be troublesome until you get the hang of the plane.

As far as tip stalls are concerned, any plane will tip stall under the right conditions if the plane is flown too slow. Aerobatic planes are actually made to tip stall to a certain extent which is what makes them tumble and snap so well.

Any airplane design is at best a compromise. Adding washout to your plane will lessen the tendancy for the wing tips to stall before the root but realise that it will come at a cost. When you fly the plane inverted that washout will become washin and have just the opposite effect. This will cause the wing tips to stall easier while inverted. This is why aerobatic and pattern planes typically have no washout at all - with these planes it is desirable to have the plane fly inverted nearly as well as upright.

The decision is really up to you whether or not to add the washout. If you are going for a scale look, don't care as much about all out aerobatics and prefer a more stable design then add the washout If you are more interested in letting it all hang out and learning to make the plane do every possible maneuver, don't add the washout.

My personal opinion is not adding the washout will force you to learn the characteristics of the design and become a better pilot in the long run. In the end, I think Dave is right, the real difficulty will be takeoffs and landings and the washout won't make much difference at that point.

I had one. Nice plane. I liked it a lot. I never had any problems taking off with it although I never tried in a crosswind. Once up in the air it was a good performer with nice scale like aerobatic capabilities.

Alas, one day I turned to final, a little too slow, a little too tight a turn, a little too low, it dropped a wing and down she went. I don't recall building in any extra washout into mine. In any event, keep your speed up when landing and don't turn too steeply on final.

In memorium...

Way to be smart, better ask question ahead of time than crash a plane like i did.
Anyways, here is a link to a duscussion and video of my crash. Hope you learn from it-

http://www.rcuniverse.com/forum/Gold...2325812/tm.htm

Commander Drake, that is one fine looking plane. I like your color scheme. Did you rebuild this plane? I will remember what you said about too steep and too slow.

Thank You
Jim Vines Jr.

In light of what you said, FlyerBry, I think I will not add washout. I appreciate your post and I definately want the plane to be able to perform upright and inverted, the way it was originally designed.

I get the feeling this plane is not for the faint hearted, and I will not attempt to fly without a lot more flight time. I will look for someone with time on this particular plane to help me.

I am anxious to get started on the kit.

Thanks, all of you.

Jim Vines Jr.

Vsustko22, thanks for the link. I read all the posts and they were informative. However, I, being a beginner have a little difficulty understand a couple of the comments concerning use more elevator than less and this somehow will make the plane react somewhat differently. I am downloading your video. I am on dial up so it's going to take a while. Thank you for your information.

Jim Vines Jr.

Jim,

Thanks. I did not rebuild it. I had already fixed it several times due to unscheduled landings while trying to learn how to operate my first 4-stroke engine (OS-48). If I build another one I will make the bottom half of the fuse, below the white stripes, blue and use a Saito engine.

Show us some pictures of your progress. We would all love to see it when it's done.

Glen

Commander Drake: What do you mean: "I will make the bottom half of the fuse, below the white stripes, blue....) ? Are you saying you would paint or cover the bottom of the fuse white for better visibility?

Jim

Jim, you're right not to add washout. Build it as is and it's a terrific plane. Just be advised of two things:

1 - do not let it get tail heavy - Due to the short tail moment it is very aerobatic, but this also makes it very sensitive, and if it's tail heavy it can snap very easily.

2 - do not attempt to float it in like a trainer. Like FlyerBri said, people tend to think that because it's a high wing that it's docile. It has a fully semetrical wing and needs some airspeed to keep flying. Do some slow fly-bys at a good altitude to get the feeling for how slowly it will fly before it stalls.

Jim,

Just picture my Decath with everything below the white stripes on the fuse blue instead of red. I saw one like that once and it looked cool.

Glen