I had a very interesting maiden flight today. I have been building a GP .60 size Cub for about the past four months and I finally got it all ready to fly. Today was my birthday so it seemed like a good day for the first flight. I tried to make sure everything was set up on the plane perfectly before I arrived at the field. I even spent a couple hours yesterday running the engine just to make sure it was properly set up.

The first problem happened when I was on the way to field, it started raining. It seems to do that in Florida just when you least expect it (the weather here is not pleasant at all). Anyway, I figured I would just wait it out and by the time I got the field it had pretty much let up. I get everything out of the car and get it assembled. It takes awhile to get all the wing struts on and by the time I was finished it started raining again. I wasn't going to let it stop me so I forged ahead anyway. I fueled it up and it started with no problems. I taxied it out to the runway and other then the rain everything was going fine. This is the biggest plane I have ever flown (the wingspan is 90" ) so I wasn't really sure what to expect.

I gradually advanced the throttle and it was on its way. It went about 75' and it started to get very difficult to control on the ground and then it did a ground loop. I have heard people talking about this with Cubs so I figured it might happen. Everything was still fine with the plane, it was just sitting there facing the other direction. I taxied it back to the starting position and tried again. The ground loop happened again and again and again. I'm starting to get a little frustrated at this point and it is still raining. Then I had another surprise, the engine quit running. When I went to restart it I couldn't get it going for anything. I came to discover that it was too hot. I will need to get some more air flowing through the cowling.

I flew another plane for a few minutes and waited for it to cool down. Once it was cool it started right back up again. By this time at least the rain had stopped. I tried to takeoff again and I kept having the same problem, it just wouldn't go straight down the runway. Then it dawned on me that I wasn't using enough elevator to initially hold the tail wheel on the ground. I was trying to go easy on the elevator because I didn't want an early takeoff. I thought I had everything figured out and I just knew it was going to lift off this time. I had it in position and started to advance the throttle when the engine quit again!!

At this point I was about ready to make an anchor out of the whole thing. I waited for the engine to cool down again and then got it restarted and back on the runway. By using some more elevator I was able to control it much better this time. It had picked up quite a bit of speed so I figured it was now or never. It rotated and was finally airborne. It was an amazing experience to see a plane of that size lift off. I did a real shallow climb and started my turn. It flew beautifully and I didn't even need one click of trim for it to fly hands off. I flew around for a few minutes and brought it in for a landing. I had no problems with the landing and it came to a stop right in front of me. I decided to give it one more try and this time the takeoff was even better. I flew around some more and then when I was on the landing approach the engine quit. I was able to bring it in just fine but I decided that I should quit while I was still ahead.

All in all I guess everything ended well but it sure was a frustrating journey getting that thing in the air. Here are some pictures:

On my taildragger, I let the tail come off the ground and use rudder to control direction down the runway.. though I have not flown a cub before. This way it will just lift off on its own when sufficient airspeed is reached.

i'd find a way to get more airflow thru that cowl so that engine doesnt shut off mid flight or when you REALLY dont want it to.

The engine may be lean too. That would cause it to heat up and stall.

I feel your pain on the rain deal I live just South of Tampa Bay in Bradenton, Manatee County.

Nice looking Cub.

are you in the rain with your tx, and its getting wet?????? I wonder also about the engine being lean.

I was able to keep the transmitter from getting too wet. It wasn't pouring rain, just a light rain.

The engine was actually set a bit rich, it's new and is still breaking in. I'm pretty sure that the airflow through the cowling is the problem. When I was running it without the cowl on I didn't have any problems.


It's tough sometimes to get away from the rain down here. It seems like it will be dry all day and then start raining as soon as I am on the way to the field.

Well the engine could have heated up or been too lean like most everyone has suggested. Did you fell the spinner? Was it extremely hot to the touch. My T-28 quit on me and man was the engine hot. I know for a fact it needs more of the cowling cut to get more air over the head. As far as the take off finally. Congrats. I had a cub and got rid of it. I just could get that dang thing off of the ground. I am an avid user or the rudder and elevator and have never had more trouble trying to get a plane to take off that that stupid Cub. I hear the real ones are just as much a pain in the rear as the ones that we fly. Congrats again and happy flying.

Well, I took the cub out again today and it is flying very well but I am still having engine problems. I knew that the overheating was a problem so I flew it today with the cowling off. That helped tremendously but then I started having another problem. I can takeoff and fly around as long as I want and the engine works fine however when I lower the throttle below about 25% it will quit. This happens every single time and as a result all of my landings so far have been dead stick. It doesn't ever do this on the ground, just in the air.

The engine is a K&B 65 and it is mounted inverted. I am using the Top Flite in-cowl muffler. Like I said, it runs fine on the ground and it will run fine in the air until I lower the throttle. I don't even have to bring it down to idle, anything below 1/4 and it will die. The needles appear to be set right and it is running slightly on the rich side. Has anybody ever seen this before?

By the way, this has to be the messiest engine I have ever seen. It spits tons of fuel out of everywhere.

Poor idle on an engine that was running OK is usually a sign of either a bad glow plug or bad fuel. Since you're having heat problems as well, I'd be suspect of the glow plug.

Brad

Yeah, people don't realize just how little it takes to destroy a plug. Just the other day I was helping somebody set their engine. They had been running it a bit lean. Anyway, their engine was giving signs that the glow plug was bad, so I told them to take out the plug. He thought I was nuts because he had just replaced it a few flights ago. He took it out anyway, and lo and behold the plug had a frosty white appearance (bad plug).

I had to put a onboard glow driver on mine to stop that problem. Mine is an OS 91 mounted inverted in a 1/4 scale cub also. Now no problems at all.

You may try leaning the low speed needle as much as possible. I have had inverted engines with the same problem. If leaning it doesn't help then as already said, buy an onboard glow driver.

For some reason a bad glow plug never occurred to me but that makes sense. I will be taking it out again today and I will replace the plug and see what happens. If that doesn't work I will look into the onboard glow.

Thanks for the help guys, I will post my results.

On board glow is a band aid that will not help and only make things worse. An inverted engine in most cubs is a bad idea, real bad The simple fact is you will not be able to lower the tank enough in that small nose to prevent hydro locks, syphoning and excessively rich low range mixtures. In Cubs the only orientation that works well is sideways and thats why almost all you see will have a sideways engine.

In the pictures you have virtually no inlet air and not much outlet either of course its getting hot and quiting.

You said you set the 'needles' are you aware the K&B Sportster .65 does not have a second low range needle but instead has that brass serrated disc that rotates the jet just slightly within the venturi throat to control the low range mixture.

Reread the instructions for your engine or better yet get someone experianced with the old Sportster series engines to help.

I do know how to adjust the engine and I am aware of where the low range adjustment is. I did a lot of reading on this engine so I knew how to adjust it before I even started it up the first time.

You're right that I didn't have a large enough air inlet hole and that has since been fixed. The reason I didn't have it larger from the beginning is that there's not a lot of space on the front of the cowling to cut a hole.


Well, I'm off to give it another shot.

I just thought I would post an update on what happened at the field today. I changed the glow plug and that seemed to do the trick. The engine was running great after that and I had it idling at about 2300 RPM.

I took the plane off to see how it would do in the air and it was running perfect. I could pull the throttle back to idle with no problems. So I thought I had all of the problems with this plane taken care of-WRONG! I was doing a low and slow pass over the runway when I heard a *boom* and I could see that something didn't look right with the plane. A pretty good chunk of the covering from the top of the wing had torn off and was flapping in the breeze. I lost about half of the covering on the top of the right wing panel.

For some reason when that happened I lost aileron control. It looked like the piece that was flapping around was wrapping around the aileron and keeping it from moving. When all this happened I immediately cut the throttle as low as I could to just keep it at flying speed. The only way I could turn was by using the rudder so I brought it around and actually got it down on the runway.

When I looked at it up close it was the most amazing thing. It looked like the covering was "cut", there are two perfectly straight tears where it separated. When I installed the covering there were no seams in this area, it was just one solid piece. I have no idea how it could come apart like that.

I think I have had about all I can take with this plane. I know that most of the problems are my fault but I have never worked this hard to keep a plane flying. Does anybody want to buy a Cub that just needs a little bit of the covering repaired

With the top of the wing gone the aileron was getting nothing but "bad air" from all the turbulance and was probably fully stalled. You were probably using plenty of up-stick to keep that side of the wing level and it had no more to give.

Torn covering from powered dives killed a lot of pilots in WWI.

Can't say what happened to the covering?? I've seen panels spontaneuosly explode with a "BANG" during winter flys when the temp is near zero F but that's usually a single tear. It shouldn't happen to a sane pilot.

I was looking it over some more today and I just can't figure out what could have caused it. It looks like it was cut with a knife, the edges are not even jagged. I'm wondering if it might have been a defect in the covering, maybe it was slightly cut in that location from the factory.

I guess I should get busy recovering the wing. I can't wait to see what goes wrong the next time I fly it.

Hey, ply2win. You've been having a run of bad luck -bad weather, engine problems, deadsticks and torn covering and all - but you seem to handle all the situations handed to you so far very well! I've had my share of that stuff as well and I'm just starting to fly solo. Bummer.

Keep plugging and things will turn around.

Happy belated Birthday by the way!

cappaj1, thanks for the kind words. Sometimes this hobby can get a little frustrating but it is all worth it in the end. I'm determined to get this plane flying after everything I have been through with it.


Thanks also for the birthday wishes, I have now reached the point where I will be the same age for a long time (at least that's what I will tell people)

Sometimes determination to get a plane flying can be the worst enemy we face. We forget to check the basics and miss something critical. It happens to the best of us. Case in point - last Sunday I went to the field expecting to spend 2-3 hours with my friends flying my current favorite plane (only because my last favorite expired on July 4). I did my usual preflight, took off, and halfway around the first circuit, the engine dead-sticked! There was a pretty stiff wind, and the plane was flying downwind, but I had plenty of altitude, so I brought it around and was on the normal approach, but a bit slow. The plane landed hard and flipped over.

When I got it back to the pit area, I inspected it thoroughly and found the reason for the deadstick - My throttle linkage had disconnected from the carb, and luckily the fuel line passing through that area had pushed the throttle closed. I had also cracked the reinforcement on the fire wall.

So I used some thin CA to repair the cracks, reconnected the throttle linkage, and back in the air. At this point, foul weather looked to be moving in, so I did a few practice landings. Finally I was setting up for my final landing and realized I had no throttle response, only it was stuck at about 3/4 throttle! Far to fast to land, so I had to fly for another 10 minutes waiting for the plane to run out of fuel. After safely landing on another deadstick, I realized that my bell crank had come loose from its mounting.

The point of the story is that I should have looked at the bell crank during the pre-flight (yes its visible), and I should have caught it during the repair of the linkage the first time. I didn't, and it put my plane at risk.

As for the covering, its interesting that the covering came loose during a "low and slow" pass. Normally, the stresses on the covering are pretty low during that kind of flight. As for the cut, it could have happened during transport or storage. "Hanger rash" is fairly common. Look at your car and your storage area for anything that might have come in contact with the wing that might have scratched or cut the covering.

Brad

That's very true and I have been guilty of that a few times. When I was building this plane I took a lot of time to make sure everything was just right but then when it comes time to fly and something doesn't work properly that is when I tend to "force it". I think that is probably a pretty common thing, when you get down to the field you want to fly one way or the other.


Regarding the covering, you may be right. I have been trying to think what could have come into contact with it but I haven't found anything yet. Maybe it was sabatoge