Skip

My Feedback: (76)

Not trying to be funny. I have a Sig 1/4 scale Cub which is harder to land than it should be. After a nice approach and flare the Cub will bounce no matter how smooth the touch down. My ego is getting shattered. Any reason for this? Could it be a little nose heavy? Should I modify the gear some way?

polstery

Landing a cub has no flare, slow down and fly it right to the ground mains first keep the tail in the air. The plane can't bounce if you land at the right speed. Just because a plane flys slow doesn't mean its easy to fly.

Skip

My Feedback: (76)

Thanks, I will give it a try. I have been flying taildraggers for a long time but this plane is a bear.

linclogs

One thing you might try is shock absorbing scale landing gear. Several companies make them but I like the ones from William Wallace of Dixie, Idaho. The bad thing is he's a "snow bird" - gone for the winter and won't be back "home" until May 1st.

Here's a link to his website - go check them out.

http://www.j3gear.com

Here's what he says about them:

"The scale landing gear will fit onto all KITS and ARF of the Piper Cubs on the market, and uses the existing mounting points. Both 1/5 scale and 1/4 scale are available, send dimensions.

Until a pilot has used a shock absorbing landing gear he doesn't understand the term. The plane can land on one wheel, instantly levels out and you have a perfect landing. Your plane can bounce hard and still give you a fine landing. Rough field operation is no problem. The plan's landing gear absorbs each and every bump and hole. It is fun as well as interesting watching the landing gear react to rough terrain.

The magic of this landing gear is the way each landing becomes perfect. We found ourselves making terrible approaches just to see how the landing gear would react. Usually the actual landing would be near perfect as the landing gear would absorb the impact."

Sounds good. I ordered a set from him for a Sig quarter scale Cub but haven't built it yet. His look the same as the other brands but I like his better. He sells them WITH the bungee covers (Robart brand doesn't include any) and his are less expensive at $100. His also includes fuselage attachment points for the wing struts, which the others don't.

You can see the other brands at:

http://www.swensonspecialties.com/Cub_Landing_Gear.html

and

http://www.robart.com/RoboStruts/Cub%20Gear.html

JohnnyJ

My Feedback: (1)

When I learned to fly in a Citabria many years ago my instructor taught me a couple of ways to land a taildragger.
Both do require some skill and practise and done properly will result in nice landings.

1. To do a no-bounce 3 pointer, ensure that the plane is fully stalled prior to touchdown, that is make sure the stick/control column is all the way back.
This assumes that the aircraft is only inches(the fewer, the better) above the ground. The airplane is done flying at this point and will bounce only if stalled in from any kind of height. A reasonable approach speed will ensure that the airplane does not run out of runway.

2. To do a wheel landing, fly the airplane smoothly onto the runway and when the mains touch the runway relax the backpressure on the stick and/or add down elevator to "pin" the mains. The airplane is still flying at this point and it is important to ensure that the mains stay on the ground and are not allowed to bounce the airplane back into the air. I find this requires more skill on my part....or perhaps I don't practise this technique as much as a full stall landing.

Both techniques work well in a full size and an R/C airplane....I find it easier for me to land a full size airplane than an R/C airplane.

Good Luck!
John

invertedpass

Sounds to me like you are experiencing the fun of flying a J-3 . Cubs are about all I fly for the most part and some will have this bouncing more than others. Try a new set of tires with a softer rubber compound,don't know how much it will help but it can't hurt. I have 5 cubs flying at this point and one of them seems to have a more pronounced bounce then the others, it does have a stiffer gear and a harder tire. Don't feel bad when you bounce just count that landing as 2 or 3 if you log your flights.

Keep flying Cubs they are always fun.[sm=idea.gif]

kcflyer-RCU

I have a Balsa USA J-3 Cub with an OS 300 Gemini twin. This plan will fly a slow as you want, but for no bounce landings, a little speed work for me. Almost like greasing it in. Make your approach as flat as your field will allow. Also don't cut your final short, go out off the end of the field a little futher than normal. Carry a couple clicks of throttle through the flair until the wheels touch. Let it roll out, while cutting power slowly. My 78" Sig cub is the same way. The slower you try to land them, the more bounce you get. Give it a try.

Good luck, Kcflyer

Yak18

My Feedback: (11)

I have to agree with kcflyer. I flew a Sig 1/4 scale Cub for 7 years. I found that if I landed with a little power on...say 3 or 4 clicks above idle, my landings were very smooth because the sink rate was much more manageable with the engine still producing power. At idle you are just sinking and have little energy left to lessen the sink rate. My landings were always 3 pointers BTW. I wouldn't chop the power until you are rolling with the tail down. To a much greater extreme, take the F-104, it landed at about 93% thrust. Anything less and the sink rate would kill you...literally!!!

Cubs are great fun. I finally sold mine because I got sick of looking up at a yellow airplane for all those years.

Yak

Isaiah 40:31

In my experience, pulling full spoilers as soon as the main touches prevents any chance of bouncing. Ha!

Step 1: install spoilers....

Skip

My Feedback: (76)

You guys are a big help!! I have my confidence restored. Thanks, Skip

PacificNWSkyPilot

My Feedback: (19)

Skip,

The number one problem I have found with cubs over 25 years is that guys tend to make their elevator throws too long. These cubs have HUGE surface areas on the elevators, and require much less elevator throw than you usually dial into a model. Upon landing, the slightest (and very natural to do) pull for flaring sends it up into the air again, appearing to be a bounce. There probably is a little bit of bounce in there, but I think you'll find it's multiplied exponentially by an overactive elevator. This can also make the model a bit "porpoisey" in the air. You've indicated that you've got your approaches down to a science and that it's still doing this, so I suspect the culprit is your elevator throws. If you have high and low rates, try setting your low rates much lower and you can always switch back if it isn't flying well, but I think you'll find a good difference there. Cubs are wonderful Sunday flyers that shouldn't bounce too much on a good approach. Another thing to check is your tires. If you're using the inflated air-type, they're cool-looking but they are like trampolines. ( Boing!) Foamies help with this a lot, but I'm not sure if they make cub-style foamy tires. Hope this is of some help.
Jimbo

RickVB

My Feedback: (24)

I'm on my third Cub (Hangar 9 80", Hangar 9 100", Sig 1/4 scale), and I've never really had a problem landing any of them (in reasonable winds ). I usually bring it over the threshold with a little power, and then just chop it, and let it settle on the mains to roll out for a while before the tail comes down (pretty much John's #2 above, but I don't use power). But before I ever tried flying the real thing, I did a couple of hundred landings (well, attempts ) on the Real Flight G2 simulated Cub, which I had a HECK of a time getting the hang of. It always either bounced and stalled or nosed over on my first several dozen attempts. I still rarely manage to get it down without at least one bounce. I credit the more difficult simulator plane with giving me the muscle memory required to handle the real thing.

Now if I could just get the takeoffs down...

dmtm2004

My Feedback: (2)

anyone have a link where I can get real air filled with a air stem valve on them, tires, to fit a great planes 80"cub?

ifly2

After reading this thread, I was worried. But I finally flew my Sig 1/4 scale cub last friday. I have a Saito 91 in it, throws set per plans.
I flew it 3 times, probably 10 landings. Only bounced once, about 6-8 inches, bumped throttle, and let her settle back. This is a great flyng
plane. Very scale like, and the 91 was at about 1/3 throttle most of the time.

Now that I have said that, I'll probably bounce all the way down the runway next weekend..

Les

Ch0pp3r

My Feedback: (3)

Check the "thumbs". If they show signs of wear, replace them...

Wayne22

My Feedback: (2)

I don't know if this relates, but my quarter scale cub is very heavy - mainly because there is a G-38 in the nose...I will sink like a brick with power off, great for steep approaches, but I have to add power for the flair..Even with reasonably smooth landings I was breaking the solder joints on the wire gear. I finally replaced it with Robart's -What a difference!! Had the first test flight last night in fairly gusty conditions, and some interesting "arrivals" ...even did some Bob Hoover one wheel landings no bounces at all!!

khodges

My Feedback: (1)

Skip- I had the same problem learning to land my 1/5 scale. I have the Wallace gear on mine, and it will still bounce (but does it with STYLE). I feel it is more a matter of practice and technique. The guys who say to carry some power are dead on. What I think happens when you "stall it in" is that when it bounces, the nose comes up more than the tail, effectively changing the angle of attack, which at this point of being at the threshold of lift, gives enough lift that the plane balloons a little, then stalls again at sets down, sometimes hard. I use two different power-on techniques, depending on whether I'm landing on grass or pavement.

On pavement, I've throttled back on final to set my sink rate, and as I fly into ground effect, I hold just enough up elevator to keep the attitude level (which is actually a neutral elevator, since I have down trim in mine to fly level at cruise setting), and drop a click on throttle. Just as soon as the mains touch, I cut throttle to idle and let the tail settle on its own. This allows a nice scale rollout, and if you want to modify it to a touch-and-go, just roll the throttle back on before the tail settles.

On grass, especially if it is longer and thicker, I fly in with a little more power on, and I am covering the elevator stick, anticipating the tendency of the extra drag on the gear to bring the nose over; I hold in more up elevator than on pavement and cut power just before touch down, landing in a slightly "nose up" attitude, but with the mains touching before the tail wheel. This allows for an immediate abort with just an application of power, and strongly counters the tendency of the tail to come up and flip the plane.

Either way, practice will have you geasing that Cub in, the scale gear WILL help, plus it looks better. Nothing prettier than a Cub taking off or landing.