Met the guys for a late breakfast then to the field. Perfect blue skies and no wind. Warmed up flying my trusty Air Tractor then made ready for the P12 test flight. After everyone, five of us, checked over the plane I taxied out and on the take-off run the foam rudder hinge completely gave way. I was able to abort and no other damage. I have less than 1 hour of in the shop time on moving the controls and glad This happened during run up and not at take-off which I was almost at speed. So back to the hanger for real hinges and will try again. Wonder if real test pilots had abortive take-offs during testing. I expect they did. We did fly for 3hr after because it is a beautiful blue-sky day. Pic of it back in the hanger4.
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Hi Rex: glad you caught that while still on the ground. You can give it another go after you have done the repairs. I've handed off my P-12 to Dan to see what he can do with it. Last takeoff attempt it rolled onto its nose before taking off, broke the propeller, and skinned the corners slightly of both wings. I'm done with this POS. For me, lesson learned. Such a beautiful looking plane, though...Met the guys for a late breakfast then to the field. Perfect blue skies and no wind. Warmed up flying my trusty Air Tractor then made ready for the P12 test flight. After everyone, five of us, checked over the plane I taxied out and on the take-off run the foam rudder hinge completely gave way. I was able to abort and no other damage. I have less than 1 hour of in the shop time on moving the controls and glad This happened during run up and not at take-off which I was almost at speed. So back to the hanger for real hinges and will try again. Wonder if real test pilots had abortive take-offs during testing. I expect they did. We did fly for 3hr after because it is a beautiful blue-sky day. Pic of it back in the hanger4.
Cheers
Davegee
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I've been rattling this one around in my head for a few days now and I'm convinced it's tail heavy. The plane just doesn't want to drag it's fat derriere into the air, so to speak.
Wes kind of hints around about that when he mentions that a bigger battery aka more weight would be a way to go.
Years ago, I had a small Waco that I went through the same thing with, so I have an idea of what to expect, but I want to check that CG!
She's still hanging in the basement, flew great, but the plastic supports dried up and broke, danged Wyoming dry climate!
Grossman56
(Dangerous Dan)Team Gross!Comment
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Grossman56,
I have several ounces of weight in the cowl of mine and it's now a little nose heavy. Too much wind today to test fly, I may get a gyro rec so I have that control. Right now, I have a 6-ch Lemon rec in it. Really want to fly this but want an almost perfect day to do it
Best Regards, RexComment
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Dave was saying that his wouldn't even get it's tail up, so that to me says waaaay tail heavy. If she won't lift her skirts and fly, makes you wonder. I ordered a 2200 4s but am wishing I'd gone bigger. I have several 3600 4s's and may try them or, like JF did, add some weight to the cowl.
I ordered the 7 ch Lemon rx with the gyro.
If you go that route, you have to set the gyro up with just the ESC plugged into the rx, once it's set up, then you plug the rest of the channels in. Not stated in the manual and I spent several frustrating hours figuring it out. They may have upgraded it now, but every one that I've got was the same.
Oh BTW, where are you measuring your CG from?
I was taught that the thickest part of the wing is where your CG is, with a biplane, figure the thickest part of both wings and split the difference. Worked great for the Pitts.
Grossman56
(Dangerous Dan)Team Gross!Comment
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I added just over an oz. of weight (29 gm) so we'll see if I can at least get the tail up. Once I get it figured out I'll find out where the CG really is and post it. Too bad airplanes have to be put out like this. I'm betting there is an inconsistency in the weight of either the tail section or the horizontal stab.
Watching Wes bounce it in on the 'fun flight', knowing that he's a very experienced pilot tells me that it's not a beginner airplane.
It occurred to me that it could be something as simple as a type-oh in the instruction manual on where to place the cg?
Grossman56
(Dangerous Dan)Team Gross!Comment
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Grossman56,
I made a new c/g balancer and set the c/g at the manual recommendations. I'll take a picture and post later.
Going to fly tomorrow so hope to test fly mine. If it's squirrely I'll put a gyro rec in, just need to order one. Mine has several oz. in the nose before it had a slight down nose position.
Best Regards, RexComment
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Success! Today a blue-sky perfect day. The test flight of my P-12 went very well. The takeoff run was short because our grass runway has some mole lines in it so after a 30' rollout I gave it full power, and she lifted off with some left torque roll that I was able to override with ailerons. The high ail settings per the manual are very touchy and a lite hand is required. After gaining altitude 3 mistakes high my caller had to add down elevator because it kept climbing with no input. While I kept the plane under control. We had all the down trim in the elevator, but I still had to hold down on the stick to fly level. Flew around high for 4 min then set up for the landing. No wind and the landing was about perfect, and I taxied back to the pits. I turned the clevis in on the elevator, 4 turns, and tried a second flight after I relaxed a little. Second flight was better, but we still had to add all the down trim. Flew another 4 min and during landing we had a wind gust crosswind, and the landing was slow and good except the crosswind turned the plane at touchdown and I bent the right axle, no biggie I just need to straighten.
My thoughts on these 2 flights
1) Ailerons are very touchy, great for aerobatics but not landing. I will set my low setting half of what the high rates state
2) Definitely still tail heavy so will add another ounce to the nose. I have almost 4 oz now in the front side of the cowl
3) has all kinds of power for aerobatics or speed but slows down and fly's well slow, I flew circles mostly at 1/3 throttle
4) turns do need rudder to make a nice turn, ail. only and it drops the wing more
More testing and tweaking will follow but it looks great in the air and think I will enjoy it once it's dialed in.
My .02 worth, RexComment
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Great report, Rex. I was talking to Dan yesterday about the P-12 and mentioned that the tail seemed "glued" to the runway. It was obvioulsy way out of wack CG wise. Very interesting that you put 4 oz in the nose. We'll remedy this one and hopefully can get the tail off the ground next time. It shouldn't have been that hard to fly, but maybe with some trimming and weight adjustments, it will be easier like what you reproted.
Cheers
DavegeeComment
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