gurumods

My Feedback: (43)

One of the guys in club has a KANGKE 105" xtra with da 100.Almost every time we do a loop with it the wings rock back and forth and it feels realy mushy.It does not do it every time,just certain speeds.Is this what is called "wing rock" and how do we get rid of it.Is it something that can be cured with balance.The plane balances out just slightly nose down.We are not big 3 d flyers and this stall just makes it tougher to do anything cause we are afraid to pull out of any maneuver too quickly.I fly it occassianally and i treat it like a trainer cause i dont want to damage his bird.Any ideas would help.Thank you.

dragonfly24_24

I am not a big 3d flyer eather but from my exp. with 3d most people have the cg slightly forward not aft try this it might help. you want a little tail heavy. Tail heavy airplanes make for good hoverings.

rmh

- for the stuff like the Kange 105" model - the plane should never be setup with cg aft 33%- ideally 30% for any 3d and aerobatics and 27-30 % for most flying

going too slow and being too heavy causes the stall and what some call tip stall (just a stall)
keep speed up and maneuvers open and smooth
In a nutshell--learn to FLY it before trying the hover and flop around stuff
The 3D craze is fun but has caused a bunch of problems which are simply results of not ever simply learning the basics

AeroDave

Doing a loop has nothing to do with 3D. It sounds like you have too much elevator throw for normal flying. Yes, we use 45 degrees and more of elevator deflection when doing 3D. But remember, that is flying past the stall, as they say. Learn to use your rate switches and get comfortable switching rates often while flying. I use flight modes on all my planes. Especially with giant scale, the normal mode rates are pretty conservative. Use too much elevator when the plane is flying "on the wing" and you'll get an accelerated stall every time. It sounds like for now you guys want to fly traditional aerobatics and enjoy that nice airplane. For now, just be sure to use less elevator throw in this kind of flying. When you begin programming flight modes, put all your rates/ expo values on one switch so its easy and fast to change. When I want to do a wall to a torque roll with my Extra, as I approach mid field I go to 3D mode just before entering the wall. After the torque roll I often pull to inverted and fly away. As soon as I'm out of the TR I return to normal mode. I NEVER fly around in 3D mode.

Anyway, this is just an example of how these things work. Bottom line: reduce your elevator throw for normal flying.

Best of luck,
Dave

marzo91

My Feedback: (57)

Yup, I agree Dave. My WildHare Edge 540 used to snap out on the bottom of every loop I made. I reduced the elevator throw from about 15 degrees down to 12 degrees. 12 degrees doesn't seem like much, but it makes pretty tight loops on this low rate. Now, I can confidently pull full elevator at any speed or atitude with no worry of an unwanted snap.

Tired Old Man

My Feedback: (1)

I've found that most people "snapping" out of a loop are just pulling to much stick for the speed they are flying at. Open up the loop, increase the speed, or both. C/G makes a difference, but the stick input from the operator is usually the controlling factor. If the plane is just flying to slow, it's going to stall no matter what attitude it may be in. A good many people are used to starting a turn or loop at one turn rate and keep making it tighter as they come around, resulting in what they think is a snap.

Edit below;

Revise the above to say:--"starting a turn or loop with one turn radius and pulling an ever decreasing turn radius as they come around. The radius of a turn is a direct function of speed. The word "rate" was incorrect for the intended usage.

rmh

exactly.
switch flippin is a crutch -and a handy one for some
learning the basics will allow you to develop a eye/hand /model reaction, feedback loop which become automatic
The idea of setting switches for a given maneuver is common but it stops you from learning to develop this feedback loop.

AeroDave

I beg to differ, Dick. I'm speaking of "switch flipping for two completely different types of flying. In 3D, as you know, we're talking about high alpha flight below the stall speed of the airplane. I only mentioned this because the original poster was asking about wing rock, commonly discussed with harriers. I felt he was confusing a 3D situation with just using too much throw in a loop. folks need to know that what is commonly called "normal" flight requires a completely different set up than that used for 3D. So I was trying to give him an example of how the 2 work. Using rate switches is worlds away from the old snap roll situation. Using programmable flight modes is the way to deal with a flight in which you're performing a long, slow roll one minute and a rolling harrier the next. It is NOT a crutch.

rmh

different intrepetations of "normal".
To me - it is a crutch.
I can do a horizon to horizon slow roll as easily on extreme 3D rates as without
Why?
I learned to fly with no expo /dual rates etc.
You had to learn to "feel" the response rather than bang the sticks
My radios have triple rates -all that stuff and for simply smooth IMAC I do back off but for most flying - I just use the 70% expo in all axis and go fly .
If a guy notes wing wiggle on loops --he needs to learn why the wings wiggle and avoid that situation not just limit throw
I have seen (and once did) ground strikes due to low throw rates.

Tired Old Man

My Feedback: (1)

I second that!!!! Taking it a step further, any guesses how many of todays current crop of flyers have absolutely zero comprehension of the aerodynamics of flying? Then guess how many think the propeller and how fast it spins is what makes ithe plane fly? [&o] How about how the engine works and the effects of altitude and temperature? They give themselves away when you see the questions about how many rpm do you get with such and such prop, and how many turns on your needles?

Those that learn a little about basic aerodynamics and how to use it's effects are likely the ones that go on to fly highly competent IMAC and Pattern. Those that don't, crash a lot of planes, grossly over power their planes, and wildly gyrate all over the sky thinking that they're in control and are just always flying on the edge. It's usually pretty evident who's who. Those that don't comprehend also are often seen "snapping" out of a maneuver, going to full throttle, and pulling full high rate "up" elevator all the way to the ground. Usually while yelling " I'm getting hit!!"

AeroDave

I don't think anyone is advocating holding full up and calling it a loop........
When I was flying pattern in the early '80s we didn't have expo. I couldn't afford dual rates. You had to learn to feed in control, not jam it in. Let's be clear, gentlemen, about who is saying what.

gurumods

My Feedback: (43)

The setup right now is sort of in between the normal and 3d modes.I think the two flight modes will help a lot.We will have to make the 3d one more agressive and cut back on the normal mode.
Dick hanson,you use 70% exp ?.That seems xtreme but i will try it someday on another plane.

Tired Old Man

My Feedback: (1)

Dave,

I'm sorry to say that there really are people that believe and do just that. I'm well aware that you're not one of them and don't begin to suggest to anyone to fly that way.

I don't know if you have noticed, but there have been a lot of posts of late that pretty much state that "the plane will snap out of the top or bottom of a loop if you go to full deflection so you may need to decrease the elevator travels" Or, " I gave it full elevator and it snapped at the top of the loop. I guess the low rates are set too high" The only way they could reach that conclusion is if they were hitting the stops with the stick to define the loop radius. I see this type of post all the time.


Although I agree that in many cases we have to define who is saying what, it may be that in even more cases we have to define who understands what.

AeroDave

Well said. Thanks. When I first replied to this thread I think I was trying to make too many points at once. The whole distinction between 3D and "on the wing" and the implications that carries for surface deflection. I should have just said "back off the elevator." I think, too, Dick hit on something when he said to keep the speed up and the manauevers open. Unfortunately, we made those two posts at the same time so i didn't get to read his until mine was up. apologies all around. Here's a funny thing...... I've learned so very much from Mr. Hanson over the years. most of which I gleaned from him before the internet even existed!

Best to you, Pat.

Dave

Tired Old Man

My Feedback: (1)

And to you. I think we are all three seeing the same picture with a slightly different method of delivery. I'd like to meet you both some day.

Pat

dragonfly24_24

I have been flying for about 10 years now but i think i have just recently learned how to fly. I perchesed two airplanes not to long ago about two weeks to be exact. the first i bought is called a twist 40 from hanger 9 (arf). Me and my brother sat up for about 3 1/5 hours and put it together very simple plane. And then i bought a TF p-51 giant scale mustang(kit). I am very anxious to put it together i have started a string on it. but anyway as i was saying i think i really just learned to fly. I am doing supperb knife edges, box loops, i even tried a blender which i performed flawlessly but my plane did not like the moneuver. as i did it with my brothers tribute .36 it realy did not like it cracked the fuse not bad landed the aircraft!! it will fly again!!!
It just goes to show even a (seasoned) pilot dont know how to fly@!!!!!!!!!!!!!!!!!

Tired Old Man

My Feedback: (1)

Blenders are really hard on a plane. Especially a blender performed under power!

bodywerks

My Feedback: (4)

Gurumods, what's the wing area of this plane and how much does it weigh?
These guys are right about how much elevator travel it takes to do a nice loop. On a plane of this size, it only takes about 5 degrees of elevator at the highest point of throw (usually at the bottom of the loop) to achieve a smooth loop. Whether or not you have dual rate thumbs or rely on dual rates switches (I do both) isn't the point, just know that it doesn't take a lot of throw to do normal aerobatics.

AeroDave

And if you must opperate your blender under power, PLEASE put the lid on securely.

uh, sorry.......

Tired Old Man

My Feedback: (1)

CHM

My Feedback: (28)

That is the kiss of death. Yes, you definately want less throw for "normal".

amjflyer

Agree with CHM. You cannot try and blend 3D rates with normal rates so you have one rate for either it wont work. Usually when in 3D rates you are using the full throws of the surfaces most of the time, on normal rates you are stroking the aircraft around in precision aerobatic manouveres. To blend the two is to create an aircraft you will undoubtedly over control as the mid point between 3D and normal rates is a throw you would almost never use in any situation.

Another thing to bear in mind is if there is a building or manufacturing fault that has caused wash-in (or no wash-out) in the wing. Most wings are built with a little wash-out to prevent violent tip stall as the wing stalls in different places at different times (as the length of the wing is moving at different relative airspeeds, on giant scale this relative airspeed difference is even more pronounced, wash-out has the effect of varying the angle of attack along the length of the wing). You can check for warps by running an incidence meter along the wing (check both sides as one may be ok the other not). Or sometimes if its really pronounced jsut look along the length of the wing for any noticeable twist.