RCU Forums - Flew Great Planes Stuka

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Flew Great Planes Stuka

Flew Great Planes Stuka.

Recommended CG was 3.625 to 4.375in. From leading edge. I set my CG at 4.2in. Because even with the strut bent forward the wheel axles where not even close to the wing LE. So I hoped the aft CG would help with ground handling and not make this a one flight wonder. Ailerons were set for max. throw, by max. throw I mean the aileron would hit the wing above it if I had any more. Flaps were set for 45 degrees when deployed. Elevator I usually set between 10 and 12 degrees this one was a 12 degrees. Rudder was as much as I could get. Power was provided by a Super Tigre S-90 (which I might add we could not get to run consistently on 10% nitro 20%oil mix, but it was totally tamed by 20% nitro 20%oil) turning a 14x8 prop..

After an hour in the sun it was more wrinkled than the seran wrap on last nights chicken but time should fix that? Once the 20% nitro was in and the engine had convince Bill and I it was done with it's foolishness I taxied out to the runway and turned into the wind. On the taxi out I noticed it was taxiing favoring one side, I knew what had happened the screw on axle on one side had come loose. So as I was taxiing I had to decide stop and wait to fix it (which probably ment not flying it today) or give her the gas and adjust for min. Smoke.

That was a tough decision! So I increased the throttle and the tail came right up. So I rotated. It rolled hard left, I slammed the stick to the right and it slowly came back to level. I'm thinking oh great another first flight from h3ll because it took for ever to get those wings back to level but they came back level and I continued my climb out now that I'm committed (wheels have left the ground). I always like to turn away from the role tendency of the plane as I'm trimming so it was a long climb out with a turn that brought it right back in front of me. The final trim settings were just a couple of clicks from were we started. Once trimmed I checked the rudder trim then thrust angle and it checked out good in both up & down, then left and right. Then the heavy panel check, and slow clean and dirty to stall. It never dropped a wing! I though with the thin wing tips this model has it would surly be a candidate for tip stalling but no. Clean it would drop the nose and immediately go back to flying without my releasing the elevator (I was trying to make it spin). Dirty I could swear it was standing still in the air before I ran out of elevator when the nose would drop and it would go right back to flying. Also when the flaps were deployed there was no induced role.

Now that all the compulsary's are done lets have some fun. I found that a good scale speed was around half throttle although full throttle was not a lot faster. I wanted to see how active the elevator was so from a ½ throttle pass I pulled full elevator to see how tight a loop I'ld get. I have to much elevator! The loop was 10-12 ft in diameter. Then I moved on to roles, I have read a bunch on how poor the role rate is on this bird (why my throw was so drastic). A 360 degree role takes for ever to complete but of center (like you would use it to bank prior to a turn it is as quick as any sport plane. Then some low passes for the camera, A out of plane barrel roll or two, and it is time to land.

So one low pass to see how that one loose tire is doing. Ooooops, its not there. A second pass just to verify, and its really not there. Now comes the adjust for minimum smoke part. I hit the flaps at ¼ throttle and it slowed like I hit the breaks, at the completion of the down wind turn I had to push the nose down to fly to the runway and reduced the throttle to 1/8 (I was still carrying some) and let the plane dive to the runway. At about 4ft I started to pulled parallel to the runway and reduced the throttle to idle, finally leveling off at about a foot to 6in. Above the runway. Now the trick was to run out of elevator at the same time I touch down. I ran out of elevator an inch or two above the ground (just as I was getting into the grass). I could have used more elevator here and it showed no signs of tip stalling (tip stall at this point means nothing accept I was going as slow as humanly possible with this plane). She touched down on the back of the wheel pants and as the plane slowed and the elevator lost effectiveness she began to rock forward until she hit the small bit of the strut that stuck below the wheel pants. Then up onto the nose balancing there for a second while deciding which way to go, finally falling over onto its back. Which was better than coming back down on those wheel pants. No damage, other than missing a wheel and axle adapter but the local hobby shop took care of that. She is ready to go again this weekend with the dubro axle kit which is much better than what comes with the kit (I had to drill thedubro's out to fit the strut).

If you want to know
Joe

Flew Great Planes Stuka

Excellent example of a well written flight test :cool:

Well done, now where are the pictures ?

Flew Great Planes Stuka

Joe, You said"It rolled left so I slammed the stick all the way over to the right." Here is the classic combination for the dreaded warbird snap on take off. You were very lucky that it did not. You should have used right rudder to get the wings level, it would have reacted much more positively and would avoid the snap-roll. If you look at most pictures of warbirds just about to hit the ground in a landing or take-off snap you will notice that there will be full aileron deflection and the rudder will be neutral. Also how many times have you heard" I had full right aileron in and it still rolled to the left into the ground." The reason is that the aileron on the left wing is down causing a higher angle of attack and that causes the left wing to stall before the right wing and it snaps left. At low airspeed and high angle of attack as in take-off and landing the rudder is the primary control to bring the wing back to level. Don

Flew Great Planes Stuka

Pittsdriver, you are absolutely correct! But the problem started long before then, It actually started when I taxied out and realized that it was tracking funny. I knew that it was one of those d**med self adjusting axles was loose. A more conservative person would have put the plane down and come back another day. But my fanny isn't strapped in it so lets see what she'll do. After the flight was over I realized what had happened was the good wheel had left the runway first (20/20 hind sight is a wonderful thing) and the side load pushed the wheel against the pants (I think it was there all through the roll out) causing a yaw as well as the drop of the wing. I did not go into this in the write-up partly because I'm embarrassed, I did a really stupid thing. I know better! I could have forgot to mention it but this discussion is important to all those just starting out (and to some of us who have been doing this for a while, my son made me add that. He's also right of coarse and knows it, you can tell he knows just by the smug little grin on his face as he reads over my shoulder). You can't always foresee what a bad setup will cause, but the out come of a good setup is always repeatable.

The blow by blow on what happened was as follows: I had been holding no elevator and had just gotten to the stage of the roll where the elevator could be neutralized and the plane was starting to turn with the rudder (meaning I was in to flying speed and could start backing of the rudder). When it lifted off the right wing lifted and the left wing did not, also I had some noticeable left yaw. I remember thinking to my self "Great another test flight from hell", as I pushed the rudder to full right but the left yaw had pointed the nose toward the ground and the rudder was not going to do the job of bringing the nose up and level the wings so in went the ailerons. As you know Rudder coupling in war birds usually pushes the nose down any how so I'm thinking get the wings level prior to touchdown to avoid the four corners landing (wing tip, nose, wing tip, top of tail post, if it holds together for all four) or a snap which at that altatude and atitude would yeild the same results. I'm not proud of it I made a mistake. I was due some luck and now I've used it up, again. I feel lucky I still have a plane and its stability saved it.

I hope to get some flights on it this weekend, at least prove to my self that, that was a one time occurrence (caused by over eagerness). Everything else in the flight tells me that it should be. The first flight is on moving pictures, so I get to go back and see how bad it was time after time. My son seams to really like that part of the tape. I'll get some flying pic's this week end and post them.

P.S. If any of you see me at the field it was superior piloting skill that saved the plane, or I don't know you!

If you can admit your mistakes you are doomed to repeat them. The problem is I keep making different ones?
Joe

Flew Great Planes Stuka

I recently started flying my GP Stuka as well, and find it is a great flying airplane, my previous experience is only a matter of hours ona trainer and a kyosho spitfire.

Had to bend the gear forward as far as I could, and on maiden flight, one of the axles came loose and the wheel rotated 90 degrees, so needless to say, full flaps, and flew it as slow as I possible could on touch down, nosed over, no damage.

Plane take off in a remarkable short stretch, doesn't roll great, but I can fly all around the field inverted no problem. Nice landing without flaps, but still has a tendancy to nose over, we have a rough field.

Nice plane, just need to figure out a fueling method so can stick the cowl on.

Mill

Flew Great Planes Stuka

Joe, I mentioned the rudder thing because a low time pilot might read the thread. Sounds like you did everything right. Just remember: a superior pilot uses his superior judgment to avoid situations that would cause him to use his superior flying skills. Don

Flew Great Planes Stuka

Don, thanks. You did well to bring it up. And I wanted to describe what went on "blow by blow" in the hope that those who don't understand any part of it will ask questions. But the key is, it was my poor judgment that put me in the situation (it was completely avoidable) and a stable plane that saved my bacon.

The directions ask me to screw the wheel pants to the wing, and anyone who has been in this hobby long enough knows that screws come loose. Landing on it would have point loaded the pants at the attachment points and cracked the fiberglass during that one wheel landing. To attach my wheel pants I completely covered with masking tape the part of the pant next to the wing when it was installed then cut slots in the tale to allow the strut to pass through it and test fit it with the wheel until I was happy with the fit. Then I poured enough two part expanding foam on to the masking tape so that it would only foam up to the wheel compartment. I also had to place the LG straps so that the pant, foam, strut, and wheel assembly could be removed as one peace. The screws have one Big advantage they allow the pant to be removed. To remove the pant from the strut I will have to remove the asm. And cut it off and refoam it on.

To fill the fuel tank I use the same set up for everything because it passes the "KISS" test. I use Fourmost Bulkhead Fittings Available from Tower and put two into the fiberglass cowl. I run one to the tank, and the other to the carb. Then run a peace of fuel tubing between them to make the connection tank to carb.. To fill I remove the fuel tubing from the carb nipple and fill the tank from that. As time goes on the only tubing that is being abused, constantly plugged, bent, twisted is that little peace between the nipples which I carry spares for in my flight box.

Joe

Flew Great Planes Stuka

Glad to hear of your flight. I too enjoyed my Stuka, it was acutally surprising to fly such a docile airplane that looks like it should have a bad reputation.
TOmmy

Flew Great Planes Stuka

First thing I did was to put the trim settings into the memory of my stylus and readied her and taxied out to fly for the its second flight. With the new Dubro #614 EZ adjustalbe axles it taxied much more like I expected. Now to make those #614's fit I had to drill them out to fit the strut, that required removing most of the paint on the end of the strut it is going on. The paint was kind of thick on mine and I wanted a good fit to avoid the same problem again.

My plan for these flight was to get to know the plane, in the first flight I was so buisy getting through the rudimentary stuff I want to know (is it truely trimmed, does it do any funny stuff, it usually takes me ten flights to get used to an airplane, comfortable). Once turned into the wind, actually I was to ROG due west and the wind was coming from the NNW, I advanced the throttle slowly untill the nose started to swing left and corrected. The objective was to track right down the center and let it lift off its self and it did. A nice gentile break from the ground and climbout, with nothing out of the ordinary. Except maybe the wind which had been calmn to 25mph all day, well if you only get one or two days a week to fly you take what you can get. I was hands off to the first turn. So I did some low passes so Bill Tozer could take some pic's for you guys then on one of the pullouts I noticed that famous Super Tigre pinging (means the engine is over heating. Down came the flaps and we landed. Well, OK I arived! Thats a term I used on Jason for meny years when his landing were not gentile. I flaired to high and stalled it to high and dropped it on the mains from about 6 or 8 in above the runway.

Reajusted the engine, four clicks richer. Again the ROG was picture perfict. This time I started to use aileron into the wind as I lifted off and it handled it very well, alowing a very slight bank into the wind.

The aileron responce is slow but acceptable and the flaps when deployed at half throttle pull the nose towards the wheels. Everything is as I expect from a warbird.

Wrinkles are kind of a goes with the teritory thing with iron on coverings. I have noticed that if after every one of the first four flying sessions I go after them with a heat gun there amount and size decreases a great deal. With this plane one has to be very carful becuse the covering has a to hot setting. If you get the gun to close or leave it to long the covering will shrival up. It does not tear, melt or get heat holes. It just srivals and usually I can smoth them out with a proper temperature iron. But just like with other coverings the second time out had much fewer and smaller wrinkles. So acouple more times and all that should be locked in.

Pic's
The best of the low pass pic's. I know the prop looks stopped that is what happend when shooting at fast shutter speeds.

Joe

Flew Great Planes Stuka

Well it looks like you will have to click on the larger picture icon to see these.
One of the takeoffs. Isn't camo great!

Flew Great Planes Stuka

I had to sneak one in of my P-51D.

Flew Great Planes Stuka

Model or mancarrying?

Flew Great Planes Stuka

Great shots. Now where was my digital camera?

Flew Great Planes Stuka

Manfred, I was a shutter bug many many moons ago, when SLR's were king. But just in case you or someone out there wants to take pictures of models in flight there are a couple of things I do that may help you or maybe you can tell me of something I'm doing wrong, but here goes.

First and most important, these pictures were taken by Bill Tozer, The P-40 was me, and he did a great job! He was using a Camcorder that can take still shots. The reason we are using a camcorder is because we are cranking the shutter speed into the 1/1000, 1/2000, 1/4000, 1/10000 speed. The bigger the lenses the more light they let in the faster shutter speed one can use. Try a fast shutter speed with your little 15mm lens digital camera and the pic's will be very dark and grainy. With a photo editing program and some experience you can take most of the darkness away and make those photo's look good. But camcorders that take stills give us a large lens which lets in enough light that we don't get the dark until we get to 1/10000 shutter speed and then we loose the corners the center of the picture is still good. That's what we have experienced on ours.

Nothing is for free and the camcorder is no acceptation, the storage of the shots is so slow that we can only get one per pass. So we need to take equal numbers of shots arriving, in front of us, and leaving. But the object was to take good digital pic's for under $400.00. Some day I'd like to try a digital SLR but they have to come way down in price first.

It took me a long time to figure out how to change the shutter speed in the camcorder because all the adjustments were in the moving picture side and not all will carry over to the still pic's side. And only trial and error will tell for each individual unit.

Joe

Flew Great Planes Stuka

Put a couple more flights on it and it performed flawlessly again. Now have one hour of flight time on it (actually 54min.). During the reheat of the covering after flying I pulled my first seam today. I don't know if I covered this before but this covering is not like monokote you can not go after it with a maxed out heat gun it will srivel right up. It has to be reset with very spacific do not exceed heat settings, I did not have time to read the info that comes with the covering roll so I'll do that another day. And report on it then.

Today my son joined me at the field and fired up the P-51D to pace the Stuka. He's setting me up for when there are alot of people around. He'll scramble right after I takeoff then dare me to avoid him. Well the gist is he's faster by 20-30mph, can role faster, turn tighter (I can fix that by cranking up the throw), and his vertical is sustainable longer. Sounds like I can expect the gauntlet to be thrown anytime now.

Experience and Gile can beet youth and exuberence regularly but he's getting smarter.

Joe