JohnMcGowan

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Hi gang...I have a World Models 60 size Zero ARF /w saito 91 .I got this plane 2nd hand . I have a problem w/ it tipstalling on the left wing. I have balanced the plane laterally by hanging it upside down on a string . The left wing was a little heavy so I added 1/4 oz of stick-on weight to the underside of the right wing and it balanced out good.I really have to bring it in hot so as not to see the"tip monster " come out of its hiding place somewhere in the plane
Its really faster than I like to land the plane.
If I wanted to raise both ailerons to give it a washout effect, how much would you raise them OR
would you just try to raise the left aileron? If I raised just the left one , wouldnt this put the plane out of trim? THanks for any help yopu can offer!!! John

BillHarris

Check the wing tips, make sure that you have a slight-but-equal amount of washout in each wing. That may/will likely mimimize tip-stalling.

Otherwise, it's a scale warbird and you may need to come in a bit hot as SOP.

Have you considered cutting the inside portion of the ailerons and converting them into flaps?

FalconWings10

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Right rudder! Always, right rudder at slower speeds.

foxx

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John try 1/8 on both side. Some thing is going on with your plane because Zeros are great flying planes without bad habits , not like some plane such as sokhoi which the tip install was built into the design. Probably the guy before you who built the plane did not join the wings correctly. Get a Robart incident meter and check the wing incident and wash outs, also stand 6 or 7 feet behind the plane and check the horizontal stabilizer to make sure it is straight, otherwise your plan will like to rotate like a screw all the time.one more thing to remember is that the tail heavy planes like to tip stall. And finally as Falcon pointed out at low speed always use rudder to turn and ailerons only to keep the plane level. A bad habit picked up by all of us flying trainers is to use the aileron for everything. Please let us know what you found out. As the captain used to say "used planes are like a box of chocolate you never know what you get"

bobnreg

up aileron on both sides. check wash out o wing tips should b approx. 1to2 degrees.

foxx

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Bob,

are these measurements for Zeros or applies to all airplanes ?

JohnMcGowan

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Thanks for the inputs guys!! The plane flies great, will do blistering rolls on high rates and w/the 91 screams flying level. Its just the landing that gets me. I flew the plane 1st time last Saturday(by myself) and was impressed with everything but the landings. Now keep in mind I am just a average pilot- well ok... not even average but I have checked the cg where the instruction booklet says it is..... its right on the main spar/ NOT nose heavy which may be indicated by the hot landing speed. I will keep trying or bring it home in a garbage bag
Thanks!!!! John

paladin

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John, I've herd that the WM Zero lands fast, but have never seen it first hand. As was illuded to in an earlier post the wings may be glued at the center section increctly. If you have an incidence meter, or know someone with one check the tips. Regardless of washout both wing tips mesured in the same place should have = incidence. Its my bet you will find a higher angle of attack on the left panel.
If so, cut the wing in half and re-epoxy it streight. Once happy with it peal back the covering on either side of the center section and glass it. I'm assuming the wing is Balsa sheeted

If you have strip ailerons adding about 5-10 degrees of spoileron will in effect increase the washout. But the amount it adds is so minimal and dependent on the stiffness of the aileron I dought it will do anything to help the problem.

Good luck

JohnMcGowan

My Feedback: (15)

Hi Paladin! Well... the wing joints are dead on even. Altho I havent checked the incidence,I will do so. When I got the plane I went on and glassed the center joint because it looked true and then recovered the wing w/ od green flat moneycoat. I will also add a little up aileron to both sides to see if this helps. The wing had quite a bit of dihedral when just looking at the wing off the plane (just guessing I would say 3 to 4 inches)but when mounted it looks like a Zero
I will give all of your inputs a shot. Thanks again!!! John

fryfly

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to answer your question foxx,most planes (not all) have a 1 or 2 degree washout on the tips especially your warbirds.
Some warbirds such as meister scale warbirds have little or no washout in the tips at all because of the flatter bottom wings that he produces. Though the flatter botoms tend to glide considerably easier they still come in a little hot without flaps.

bobnreg

Hi Foxx this applies to planes that tip stall Zero included

BillHarris

An incidence meter is reasonably accurate and gives numbers to look at.

The most accurate way to check relative incidences along a wing is to attach 1/8" dowels about 24" long with a rubber band to the bottom surface of the wing so that several inches projects ahead of the wing. The rod has to be straight, I use carbon fiber rods. The rod attached to the wing root is the "zero reference". Stand back several feet and sight spanwise towards the root. Another rod placed at mid-semi-span should be parallel to the root rod (indicating identical incidence), and a rod placed at the wingtip should have it's tip lower than the root rod, indicating less incidence, or washout. The exact amount can be calculated by using trig.
For a built-up wing, twist and shrink the covering to make corrections. For a sheeted foam wing, a error is a warranty claim....

Richard L.

My Feedback: (24)

Unlike the WM Zero ARF, the Kyosho Zero ARF lands slow and has no tendency to tip stall. I landed her deadstick a couple of times, and she came down as smooth as silk. I double checked the wing, and sure enough, the wing has around 1.5° of washout at the tips. It is nice to have wing washout on a warbird. On the contrary, my gray VQ Zero has no wing washout, and it lands fast like the WM Zero. If I come in too slow, the left wing would drop. I learned that out the hard way three feet above the runway one day.

KJohn

I would suggest that you check the following:

1) There is washout in the wingtips (mentioned above)
2) The washout is the same for both wingtips (mentioned above)
3) The airfoil is actually the same at each wingtip (contours accurate)
4) The wingtip leading edges are not sharp (blunt is better)
5) Verify aileron movement in 'down' direction does not 'induce' a tip stall
6) Wing is balanced correctly (apparently it is)

I don't think there is much else that influences a tip stall. Washout seems to help sooooooooo much that I would really make sure washout is present and the same for both wing tips. I have played with minimum to excessive washout and it is suprising how much it helps in control during a slow, nose high landing.

Hossfly

If you are receiving no adverse problems during take-off, however wing drop during landing, then IMO, while raising BOTH ailerons for washout could well be the answer, I suspect that the problem lies more in some slight difference in angle-of-incidence between the two wing panels This could be a number of very small differences. I suspect, from your description, the right wing is slightly high.
With No takeoff problems, simply using rudder to catch the wing drop and/or preclude such is also an answer.
You will trim out the problem in normal flight. Then when you slow down the left wing has some down aileron trim, which will cause higher drag on that wing. You probably note a slight tendency for left roll and apply right aileron which causes the left wing to quit flying before the right wing. Thus left wing drop.
IMO. I would add significant aileron differential, prior to doing anything else. I suggest a 2 to 1 on scale models. 2* up per 1* down.

Had a 40 size HOB P-51 way way back. Had a significant warp in right wing. Trimmed out fine in air. Just had to use left rudder to hold wings level during round out. Did it for years.
If it were incidence in both wings, you might well have a takeoff problem like jumping off the ground too soon or maybe not.
Had a scale-incidence (Dumb to do that!) Spit, max power and minimum w-area for engine for Scale Warbird Mini-Reno Racing. Worked months to get reliable take-off with that little monster. Finally raised both ailerons about 10* and It was THERE. In the first race after that fix, just as I was passing overhead a dumb P-51-driver pulled up and sliced the fuse into, half way between the wing and Stab. We were down low, field out there was very much DUST. Spectacular CRASH. Looked like fire and smoke, as she re-kitted herself for about 40 feet along the way. Just nicked his prop! YUCK
Good luck.

JohnMcGowan

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Hey Guys ,.... thanks for all the response. Due to rain nearly EVERY day here in Bama for the last week and a half, I havent been to the flying field. Possibly tomorrow after work I can go and I will post results. See ya!!! John

nbcguy

A gentleman at our field has a PT-19 that would tip stall at slower speeds. He solved it by installing what he called a "stall strip". This was nothing more than a piece of 1/2 inch triangle stock glued to the leading edge of the non-dropping wing in towards the fuselage. He said that some full scale planes use the same technique and what it does is reduce the lift of the "non-stalling" wing and essentially evens out the incidence. The piece of tri stock was about four inches long or so, and once covered with matching material worked perfectly.

It is almost too simple, but the PT-19 went from a violent tip stall to just mushing over at the stall speed.

There might be some more info about this somewhere in these pages.

taildraggerdave

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The WM Zero has the stall strips installed at the factory. At least the Zero with flaps has them. I figure they both would, though.