ser00

Hi everybody,

I have a question for those that fly Piper Cubs. I have the Great Planes 40 Piper cub ARF with a Enya 60 (or is it 61) two stroke engine on it. I attempted to fly it last weekend and lets say that the maiden flight was less than desirable. I slowly advanced the throttle until the tail came off the ground. When I proceeded to advance the throttle, the plane took a sharp right turn. It hit a little bump and it was airborne at 1/3 throttle. Well, long story short, the plane tipped stalled and cartwheeled. I was taking off into a pretty strong head wind so this probably helped facilitate the tip stall. Luckily, the only damage was to the firewall which I will need to cut and install a new one. Now, I have flown other planes with no issues (Pulse Xt, P-51 Mustang, Ultrasports, EasySports, ect). What I thought was strange was that on advancing the throttle, the plane went right when, if anything, it should have gone left due to P progression. I really want to fly this plane soon but do not want to have another mishap. I have no problem using rudder for ground taxiing. I think part of my problem was that I did not expect it to turn so hard to the right and become airborne so quickly. I might need to hold a little down elevator during the takeoff roll to try to keep it on the ground longer and release it when it is fast enough to take off safely. What is everybody's experiences with take off for the Piper cub and does anybody have any pointers for me?

Happy flying and soft landings!

MinnFlyer

My Feedback: (4)

I find that whole theory of "Partial-Throttle" takeoffs to be bunk. If a situation like you had developes, you don't have as much pull as you need to keep it moving.

The pull to the right IS puzzling. I would first check that both wheels are straight AND spinning freely. Roll it on a smooth, flat surface and see if it turns to the right.

Then, on the next take off, add throttle gradually - that is, not slowly, but don't slam the stick forward either - but gradually to FULL power.

Live Wire

ser00
Check your thrust line on your engine Then add a little left trim on your rudder on take off and fly the tail of off it. Minn is right on when he said ,give it full throttle on take off but I just use a mag. 52 4st.
Larry K

gsoav8r

My Feedback: (6)

I agree that until you learn the characteristics of your Cub you should be taking off near full power. Cubs have a lot of drag a slow quickly. Another thing is that Cubs are a handfull in high wind like 10 mph or better due to light wing loading and having a lot of side fuse area. My Cub weather vanes better than any other plane Ive ever had/have. Once your more in tune with the Cub then have a ball doing long takeoffs at 1/3rd throttle.

Also, of the Cubs Ive flown Ive found that if you can Toe In the mains a couple degrees they track much better.

Rodney

Gear set up is quite important also. Make sure to have some toe in on the wheels. You do have to manage the rudder on takeoff though. Maybe a bit of exponential on the rudder would help as it is easy to over due the corrections if it starts fishtailing on you. Keep it on the ground until you are sure you have adequate flying speed.

redfox435cat

you have an overpowered tail dragger that is a floater, when you have an over power floater you need to use the rudder. The prop is torquin the plane over.

for the first couple Take off give a good moderate push on the throttle. At the same time hold in some Left rudder. As it gains speed let off and bump full left rudder and some right rudder to keep it stright down the runway, you gotta be quick. Once you learn what it going to do you can just push full throttle and bump full rudder to keep it straight. The trick is bumping it, if you hold it as soon as you see the result your off the runway. With the rudder to the left the plane may bank left also, so you'll need to use right aileron to keep the wing lvl. Steer with the rudder and keep the wing lvl with the ailerons. As soon as the tail comes up it can fly

Gooseing the power slowly is not going to help you. With a new model your going to maiden it's usually best to poor on the coals and yank it in the air and gain as much altitude as you can. The one thing to watch for I found with the 40 sized is putting full aileron rudder and elevator at the same time it will do a 3/4 snap roll on you on you. Once you learn how the model reactes at slow speed and high power then you can try realistic slow take offs.

red head

Another thought: Are you sure you are releasing the rudder when the plane breaks ground ?? Sometimes we tend to over steer on takeoff and then hold more rudder then we need after liftoff.

I always hated cubs because they were so hard to get used to taxying. Now that I am used to it I have a ball taxying and slowly getting the tail up and making scale takeoff's. Touch and go's are also a ball, especially one wheel at a time. I got a lot of practice when I mounted a swivel tail wheel on an Aero Bat ( Midwest ), now that will keep ya busy, especially with a little (cross ) wind.

Take your time and just be patient, " It will come to ya ". ENJOY !!! RED

Stick 40

I got a hanger 9 j3 cub with a saito .56 on it. The .56 4 cycle is lots of motor for that plane, I think a .60 2 cycle would be a hand full at best.

I can take mine off with 1/2 power and fly on 1/3. Don't put the power on as fast as you can, try and bring it up gradualy.

I had all kinds of trouble trying to land and take off my cub, untill I put TOE-IN on the main gear. That made all the difference in the world, it tracks stright and is fun to take off and land.

the wheels should have the same amount of toe-in, to help it track stright.

some said to put camber into the mains ( wheels tiped in at the top) but I never did that. I did not need to, it ground handled just fine with the toe-in.


sticks

Mikecam

I just maiden my GP Cub 40 arf. First 3 tries at takeoff spun the plane around. I was to tentative on the rudder. I even went out and checked my wheels thinking one side must be binding but they were good. Make sure the wind is low the first couple of flights and if it starts to turn cut power right away and try again. Make sure you are heading straight into what little wind there is. I also fly a TF mustang and small rudder corrections are enough but the cub needs to be quick and precise. Sounds hard but I've been out 3 more times including once in 15 mph winds and once you get the hang of it and learn how quick and how much rudder to put in it will become second nature. But remember if it starts to turn CUT power and try again. Good luck.

sportrider_fz6

don't get discouraged, I'm in the process of recovering my wing again.... I have had three successful flights, once it's in the air I enjoy it. and I find it almost lands itself. I should be ready for another round in a week or so. just look at the bright side, my Cub has made me a proficient re-builder

bkdavy

My Feedback: (1)

All the planes mentioned by the OP have a fairly long tail moment compared to the Cub. The Cub, with its short tail moment, is VERY prone to overcorrection on the rudder. This will become more of an effect as the plane gains speed. If you're expecting the plane to go left, and holding right rudder, you have to release the rudder as the plane gains speed. As this was a maiden flight, trims could have been anywhere, contributing to the problem. There is also no mention of control throws. If control throws are set more than recommended, this could aggravate the problem. Also, if the plane was slightly tail heavy, this will increase elevator sensitivity, and could contribute.

My guess is that the OP simply over corrected with the rudder, and was then pulling up on the elevator too hard, causing the tip stall. We have one pilot in our club that I can almost guarantee that on any maiden flight he'll tip stall. Its a natural urge to want to pull the plane into the air as quickly as possible, but the plane must be allowed to fly.

Brad

ser00

Hi everybody,

I appreciate everybody's input. I will apply the throttle quicker next time. Since there was a good wind blowing that morning, it is a good chance that once the plane went sideways, the wind helped pick up the wing, exaggerating the tip still. All controls were set to neutral position, but the elevator looks like it might have had a bit of up in it. Now, the balance (CG) seemed to be pretty balanced (almost too balanced). I tend to fly my maiden flughts nose heavy, but this one was right on the money. I will add a little weight to the nose until the plane is trimmed and I better understand its flight characteristics. As always, I know I can always find the answers I need on this great site.

Happy flying and soft landings!

j.duncker

My Feedback: (2)

One of the things to do is ABORT the take off if it veers off course significantly. [ Esp. if windy.]

If you can not keep it on course, say no more than 10 degrees either side of line, give up and start over. You will need to coordinate rudder with throttle opening on a Cub and be very sure that it tracks in a straight line before doing anything else.

People do get away with snake like take offs some of the time but not forever.

apwachholz

ser00 -

I have actual on board video that replicates your initial crash and found what the issue was for me: Over correction of rudder on take off which caused me to asymetrically stall (commonly called a 'tip stall'), roll left, and flip. Not a pretty sight. Essentially I was using too much rudder to keep straight all the while using too much alieron to keep wings level. When I released my rudder to quickly my wings rotated too fast (yaw) causing more lift on one, and none on the other (thus causing the stall/flip).

I fly a Hangar 9 Piper Cub J3 and love it. But one thing that I've noticed is that its ground handling on take-off on rough grass almost always causes me to suddenly shift direction on take off. Wheels are straight, balance is perfect, winds are fine - it just isn't heavy enough to track straight on rough ground. For me it usually equates to two things attributing to take off issues:

1. Bumpy or undulating ground (i.e. no tarmac)
2. Adverse Yaw Effect

For me it's the latter that get's me most of the time. And like others have mentioned, it's a matter of practice. I gave up the Left-2-Right or Right-2-Left take-offs and instead went straight ahead of me concentrating only on keeping the wings level. Once i understood 'how' the plane was behaving and started to understand how to compensate for the yaw I stared doing L2R and R2L take-offs. It just takes practice. And for my part gunning the throttle makes it worse. Give it what it needs, the Cub wants to fly - and concentrate on keeping the wings level first. You can always take off going left or right, but if your wings aren't level you'll go no where fast.

Cheers!

frugalflyer

I've found the cure for the cub poor ground handling is to move the wheels foreward.
This can usually be achieved by putting packing under the rear support. It is essential that the wheel axle is ahead of the wing leading edge.

FILE IFR

No. It is essential to use rudder in ALL phases of operation.

Neil9139

I have a H9 - J3 Cub 40 size and had the same issues on my initial take off runs. It was a surprise to me as well, I found the rudder to be very sensitive at best and almost to point of going back to the drawing board on this bird. But I didn't, the good thing for me was is that I quit early when the plane was headed due east/west and fish tailing all at once. I chopped the throttle and tried again ba-da-bing same stuff again. On the third try I managed to get some good air speed, halfway straight and lifted off right before I went off the edge of the runway. Wooohooo!!!! The plane flew great, "landing no problem".
I re-fuel and here we go again with the dancing thing, I got used to it, talked to some buddies they said: (1)Check your wheels, guess what? they were toed out. Apparently I missed that in "oh yah check to make sure your wheels aren't toed out" section of the instruction book. (2) How much expo/throw is in your rudder? No expo and 2"you know just in case. The guy said you "may" want to change that. AhhhHaaa It worked great all of the sudden. Happy Days are here again, and there has been plenty. Suddenly that plane is the sweetest flying thing in the hanger.

Best of Luck
Neil

DRC1

My Feedback: (10)

Somebody else mentioned this as well...I suspect the physics are the culprit and most likely not related to the Cub's set up or build concerns...

The wind, most likely more of a cross wind will cause the plane to turn into the wind about the same moment the tail wheel lifts and loses traction...

The solution is to take off a bit more into the wind if possible and/or hold up elevator to keep the tail wheel in contact with the ground until the airspeed is high enough to over come the cross wind. You may also want to hold a verysmall amountof aileron to slightly bank into the wind on takeoff / landing (about 5 degrees, just enough to keep the wind on top of the wings surface) ...This will keep the cross wind from getting under the wing causing the plane to roll and hitting the other wing panel on the ground causing a cart wheel...

Hope this helps...

LLD

ser00

Hi everybody,

I do appreciate everybody's advice. I really think my problem was that I was not prepared for the cub's handling. It is not that I am not good enough to fly the cub, it just took me by surprise as to how squirrely it was. I guess guess the cub grew up into a grizzly and smacked me across the head with one of its claws. As I stated, the plane is very fixable and I plan on hopefully flying it over the weekend. I also ordered myself a CG anniversary 40 cub to build. I plan on doing that one as a L-4 grasshopper.

Happy flying and soft landings!

ramboman

Hello everybody,
I crashed my H9 J3 1/4 yesterday during the maiden flight...
After take-off... far from correct... she began to fly everywhere...
Probably tail heavy and overcontrol on the commands...
Finally I decided to crash land with minor damages... wing tube and wheels...
CG was correct at 114mm and the commands set to high... following the manual...
I don't understand what happend...
Learning from others I plan to change the CG to 102mm (4" instead of 4.5")...
- ailerons to 16up 13down instead of 28mm
- elevator to 22mm instead of 51mm
- rudder to 38mm instead of 57mm
That's less than "low" in the manual.
Does anyone have experience with this plane ?
For info... power is Cyclon 160, CC HV-110, 12s2p a123, prop Menz 19"*8"...

mike109

G'day

I have had three Cubs. I have sold two but still have one. The first was a Carl Goldberg Anniversary which I bought part built. It had been set up for an OS 70 Surpass so that is what I put in it. It flew well and I did not have problems with flying it apart from the fact that RUDDER was absolutely necessary on take off and landing so as I am not the best rudder user, I mixed some in with the ailerons and it became a complete kitten to fly. Really easy. The 70 was really too powerful and I later put an ASP 52 four stroke in it which made it more realistic and better to fly. I used to use this Cub as my windy weather plane. It penetrated really well and was not badly affected by wind. Our strip ran East West and Northerly and North West cross winds were very common. Despite this, I found it flew well in the wind. It was not light but it did have a lot of wing area.

Next was a Hanger 9 quarterscale. I powered this with a Saito 120S and this was more than necessary. I had it set up with differential ailerons and after my previous Cub experience I also set up switched aileron to rudder mixing. It too was an extremely easy model to fly especially with the rudder mixing. I only flew it about five times and recently sold it as I just was not flying it enough mainly due to its transport difficulties.

Most recently I built another Goldberg Anniversary model and finished it as a WWII Cub that was loaned to the RAAF by the US forces in New Guniea. It has a Saito 90 twin engine which is perfect for it. Powerful enough and looks and sounds great. I have set it up similarly to the other too - differential ailerons and aileron to rudder mixing. On our bumpy field I do not rapidly increase the throttle as this can cause models to bounce into the air before they are actually flying and this usually results in a stall and a cartwheel or at best a ground loop. Once the tail comes up and she is heading straight then I add power and she just floats off. With the rudder mix she is totally easy to fly. Without she tends to skid a bit in turns but is not impossible to fly.

I also have a Decathlon. It is similar to the Cub though the wing is shorter and her power to weight is higher. She is a 60 class model and is powered by a Laser 100 four stroke. She, like the Cub, MUST have rudder in turns or she simply skids wide and does not turn at all neatly. If I just whack the throttle open and not pay attention to the rudder, the will start her roll then turn 90 degrees to the left and roar into the air. If I keep her straight with the rudder and use a little less power her take offs are far neater and more scale like. Without rudder she is nearly impossible to land well. She just wanders off to the right every time once the speed drops to landing speed. With some rudder she stays straight and is no problem to land.

Hope this helps a bit.

Mike in Oz

Picture is of the CG Cub on landing. Note the aileron and rudder settings.

Augie11

Lots of suggestions on here, some good, some questionable depending on your perspective. I have 3 Cubs, a 1/5 scale on wheels and a 1/5 and 1/4 on floats. All have ample power but yours is somewhat overpowered with that .60 2 stroke. Here are my suggestions.

Make sure she rolls straight AND has some toe in. CG slightly forward of recommended mid range point. Program in aileron differential and a little rudder to aileron coupling (maybe 10%) and a little expo on rudder (maybe 10%). Get her pointed into the wind as much as possible and manually hold a little aileron 'into the wind' if it's a nasty crosswind. Apply power smoothly but firmly on takeoff don't jam in full throttle. Hold the tail down lightly until she lifts the tail but let it come up before breaking ground. Stay on the rudder because she can EITHER try to weathervane into the wind or pull left from the P factor. Sounds tricky but it's not. You're trying to stay ahead of the plane rather than react once it's too late.

If you can, practice off grass......it's much easier at the beginning. Tarmac can be 'slippery' until you get the feel for it. I've been at many fly-ins where stiff breezes ground everyone for a spell and the first planes that seem to go up when the wind lets up are Cubs! Once you have more confidence in your takeoffs you can begin practicing cross wind landings by crabbing into the wind but thats another issue.

Good luck!

ramboman

Thanks a lot.
Any suggestion about the size of movement for ailerons, elevator and rudder ?

Augie11

Check your manual for the throw recommendations. Pick the midpoint between high and low rates and start there, then use your Tx EPA to adjust to your liking. For a Cub you want considerable rudder throw, about the midpoint on elevator and mostlikely toward the low end on aileron. Some may advise setting up dual rates. On a Cub I don't use them as I don't fly them like an F-16. Throw in that expo, 10-15% on everything.
I don't have your exact plane but lets say they advise low rudder, 3/4 to 1 1/4 inches and high rate 1 1/8 to 1 3/4inches. You want to have plenty so set up at about 1 to 1 1/2 inches. On the aileron low they may call for 1/2-3/4, high rate 3/4 to 1 1/4. I'd go with about 5/8 to 1 inch. You will probably want to increase your rudder after a few flites and maybe decrease the ailerons so use the Tx.

Gray Beard

My Feedback: (-1)

I just maidened the CG Cub that Mike mentioned, great plane and built like a tank. In this build I installed the OS .91 FS, it's what the owner had and he is installing floats so that's what I used. No trim needed on maiden at all. I had set the controls up with a degree meter so ailerons and elevators were set at 12 degrees up and down and all the rudder I could get. I used no Diff at all at this point. It fly's so well none is needed. The CG was slightly nose heavy. From how you described the flight it sure sounds like you have a tail heavy plane. Most the time I do the toe in LG like Augie mentioned for ground handling but on this plane it is using a one piece after market LG so the wheels are straight. Other then having to almost come to a stop on roll out after landing. If it doesn't come to a near stop it will do the normal ground loop when trying to turn. The owner installed the little plastic wing tip savers so the plane didn't even get a scrape on the wing tips.