I,ve been flying helicopters for about a year or so now and decided to get a plane for something a little less stressful. I had a plane a long time ago but got rid of it for lack of place to fly. My new found plane , so far, hasn't been that relaxing. I built a Lanier Stinger 40, it's powered by an Enya ss40 with a 12x7 prop. I've tried fueling it with Cool Power 15% (thats what I run in my heli). I tried a first flight the other day and spent about 4 hours trying to get off the ground. I leaned it out, richened it up, changed to larger fuel lines, it just doesn't want to gome off the ground. I was in a large sports field and had about 500 feet of runway and was using it all. Being a tail dragger, as it went down the runway the tail came up as expected, when the plane got to what is aparently full speed I gave it some elevator, the tail would dip down, the plane appeared to get a little lighter, but that's it. It continued down the runway just bouncing on the grass. Not hopping like it was trying to fly, just a little bounce..

My question is..... should I be running different fuel....... or a different prop.......... different engine....... I'm not sure where to start.

Any Ideas?

That is a huge prop for a 40 size engine. Toss a 10 by 6 on there, and i would get some buddy time since you haven't flown in a bit...

I'm going to jump in here with a guess as much to test my own beginner's knowledge as to offer a reliable answer. I'll warn you now...there's probably at LEAST a 50-50 shot what I'm about to tell you is complete bunk, so take it for what it's worth.

The reading I've done, and my understanding of props would suggest to me that your prop is just on the ragged edge of providing enough thrust for climb. Most of what I've read suggests that 10 x to 12 x 6 is about right for a .40 sized engine on that plane. Tower, in fact, suggests an 11x5 for that range of engine.

I suspect, simply, that the engine isn't capable of turning such a large, high pitched prop fast enough to generate the speed required to get off the ground. While it would likely FLY the plane, it can't pull it off the ground into flight.

As mentioned above, your mileage may vary.

HTH

Darnit, Chad...ya beat me.

Now I look like a copycat

Makes me feel a TAD better to know that I actually came up with the same answer tho *heh*

A 12 inch prop sounds outrageous for that. I would be lucky to get a 12 by 4 to spin enough for takeoff on my 40 la

Fishdeep,

First off I have to agree that the prop is just way too big, you are not getting thrust. If you have the ground clearance which you obviously do go to a 11X5 so the engine will come up in rpm's

Verify the CG. Even with the right prop if the plane is too nose heavy it may get off the ground but will take allot of up trim in flight and will land really hot. That is a mid wing plane but almost to the point of a high wing so when you balance it make sure the tank is empty and the plane is upright.

I just looked up the specs and the CG is as follows, this is taken from Laniers web site

The CG on the Stinger 40 is 3" to 3-3/8" behind the leading edge.

I would start with the CG set at the 3 inch mark. If you need to know how to balance it just make a mark on the bottom of the wing at 3 inches behind the leading edge of the wing right next to the fuselage on both sides. Now pick up the plane with your index fingers, one on each side, with the nose facing you and it should set level or very slightly nose low. If the tail drops then you are tail heavy. If the nose drops more than a 1/2 to one inch then you are too nose heavy. You can proably move the battery around to get the balance correct

Also verify your throws which again are taken from the Lanier web site

The elevator throw is 1/2" the ailerons are 3/8" and the rudder is 1".

Hope this helps and let me know if you need anthing else

Bubba hit the nail on the head. Good post bubba

that engine should be swinging a 11x5 to 11x7 and like he says, check cg and throws, geeze, heli people

10 X 6 prop

A Stinger is a relatively hot plane. Are you sure about this ?

Yup 10-6 or a 11-4 No More. That engine is ported for a good turn of RPM's it needs to breath. Also pay careful heed to bubba's post especially concerning CG.

Its hard to tell if you have ever really flown fixed wing from your post and what is a bit alarming is the fact that this is not a very approriate starter fixed wing and you are doing it at what may be a confined sports field with other folks around. If this is the case get help and a buddy box.

John

Thanks for the help..... I think I'll start with a new prop. The CG is at 3" as per plans. The other plane I had a while back was an LT40 or similar. I bought it used @ a yard sale and taught myself to fly it, never had to make any changes except turning the needle. As far as flying with people around,.... even though I'm a heli guy (LOL) I do know better than that.


Thanks again for all the helpful advise.

Also check that you have enough deflection on the elevator.
I build a DeHavilland Beaver that wouldn't take off on the maiden flight because I hadn't enough deflection on the elev.

Sorry. I did not know what you knew as far as planes go so I figured I'd cover the most common taildragger takeoff problems. I did a little research this morning trying to find the manual for that engine to get the recommended prop range and although I did not dig to deeply I did find a dealer that listed the props so here they are

10.5 x 6 to 11 x 7

So I am pretty convinced the 11X5 or 11X4 props will be just fine. I would recommend the APC brand but that's just me. It's what I like.

Chad,

Thanks for the nice comments, are you feeling alright [X(]. These posts are a good example of what you can find out with just a little searching. Although I expected based on experience what prop was a good one, a little research confirmed it

Bubba,
It really depends on what prop is best. I think for tourqe the 11 by 5 works best for me, but for speed i throw a 10 by 5 on there. I think the 11 by 4 would work best for him.

Could you explain to me how a 10X5 will give more speed than a 11X5. [sm=confused.gif] In detail please

oops, i meant 10 by 7

From your opinions on APC props, i decided to pick some of the other day. ALOT of people at my field use them also. I got a 10-7 and 11-5

For what engine/plane combo ???

i have just been running it on the four star to test it, but it will go on the stick. I can't decide if i want speed, which will help take off speed and reduce stalls, or tourqe. I guess i will just have to test it out.

If Iremember correctly that's a 50 size engine, cannot remember the brand right now. A 10 inch prop will over-rev that engine big time at full throttle

If you remind me about the make/size of the engine I could help you better.

I am talking about to 40 LA. Not the G-51. I put the la on the four star, but the la will go on the stick. I have clamp mounts for both planes, so i can switch whenever very quickly if needed.

sorry about that

time to get this thread back on track...

Fishdeep,

Please let us know how you make out with the changes that were suggested

Torque will let you accelerate faster, break ground sooner, dig out of a stall condition better and what do you need speed for? Are you in a hurry to get the plane to the crater?

How many times does EVERYBODY need to tell you to slow down a little and learn the basics?

Do you ever intend to listen to anyone's advice? A big post count does not make an expert or even a solid beginner pilot, Flying does. You've owned/flown exactly one plane and that does not qualify you as an expert. Sorry if this offends your ego.

If you have a tach, look for at least 12,000 rpm on a 10" or 11" prop. I would bet that with a 12-7 prop you will be under 10,000 rpm which just won't cut it. I would suggest go fro a 10-5 or 10-6 prop with that engine, no more. APC are more efficient bbut alos load up the engine at higher throttle settings so expect lower rpm numbers with the same prop size and pitch.[8D]

Bruce,
Speed will eliminate stalling in the first place. But i do see where you are coming from. You have permission to PM me so we can get this thread on track. Who said anything about postcount?

Well you do have to land, A good landing is just above stall or better still right at the stall so if you over prop on pitch, do you plan to do a deadstick landing to get the plane slowed enough to quit flying.