While flying this plane, it needs down elevator (up on transmitter) to make the plane fly lever at 1/2 throttle. While attempting a loop, the plane just kind of falls out of it right at the top, the tail just drops away. Fuel tank has a small crack in it at the top, will this cuase air bubbles in fuel line to carb and starve the engine?

So is this thing tail heavy?




ps, while landing it will drop like a rock, have to fly in and land under power.

It's a typical Duracrap. [X(] It's heavy, has a high wing loading and may be underpowered. You don't say what engine you have in it. All these things will cause the symptoms you describe. It may very well be tail-heavy also. Balance it approximately 25% of the wind chord back from the LE of the wing.

Good luck with it.

Dr.1

Your tail heavy, have to much elevator throw or both. The tank is no good... buy a new one. Yes the tank will absolutely cause an air leak, air bubbles and lean run's... not to mention deadstick's. I've only test flown one of these thing's... I can't say it flew well but it flew... it's a heavy plane so it will need some speed on landing.

John

Ok thanks for the replies, I will rebalance this thing and get a new fuel tank. Oh, and it is powered by a new OS 40FP with a 9x7 prop. Have to use 9X7 for ground clearence.

A 40 fp should fly the plane... not much more. Your down on power so you may need to get as much speed as possible even a shallow dive to complete a nice size loop... that could explain the tail wag and fall out at the top of your loop... of course a tail heavy condition or to much throw could be the problem. The down trim could be caused by a number of thing's... double check the CG and throws... if their in line with the book then look at the elevator with the radio/plane on... put a ruler on top of the horizontal stab and look at the control surface in relation to the ruler... is it level with the ruler? is it hanging down from the ruler or holding it up? the position will tell you exactly what your trim adjustment is doing to the control surface... if it's almost level reset your trim and check it again... you should see the surface is holding the ruler up... correct this at the servo or control horn by moving the servo arm or clevis so the control surface is sitting level with the ruler. If it's down and reseting your trim puts the control surface level then you need the down trim for level flight... it could be wing or horizontal stab incidence is off causing the need for down trim... I would'nt mess with it if that's the case. You could also change your CG to be a bit more nose heavy... it should help with trim BUT it will make the plane fly nose heavy so again unless it's showing sign's of being tail heavy in the air with the CG set correctly(by the book) I wouldn't mess with it... a little down trim on a trainer type plane won't hurt it.

Replace the tank, double check everything is by the book and if at all possible get someone with experience to help you out... the net is great but hand's on is the best help you can get.

John

I 100% disagree with this. I fly teh Durastik and its the best plane I've ever had. It flies right where you point it and has no control problems. Yeah it has a little higher landing speed, but that just makes it that much more fun to land. Unless you have flown one yourself, you have no room to talk. Lets see your balsa plane have a radio failure, hit a tree, and be ready to fly the next day.

Yeah it has a little higher landing speed, but that just makes it that much more fun to land.
Not for a beginner.

Unless you have flown one yourself, you have no room to talk.
I have plenty of room to talk from having flown several and tried to teach novices on them. I don't pull my advise outta my rear. Anything I post is something I've either done or seen done. I'm glad you love your Duracrap, I, and many others, hate them.

Lets see your balsa plane have a radio failure, hit a tree, and be ready to fly the next day.
Yea? A brick can do that.

Dr.1

carlson,

Find a way to get more ground clearance and get rid of that 9 x 7. You need a 10 x 6, 10 x 5, or a 10 x 4. The 40FP is marginal on that plane, IMO.

Dr.1

An 11x5 would be even better.I too have one and I like mine also.I don't fly it very much anymore but I enjoyed it when I had nothing else to fly.I have sucessfully trained others to fly with this plane.It was the DuraPlane 40 Trainer,not the DuraBat though.It is important to have the center of gravity set dead on.