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     yep, that made my morning. 

All the Avids I've been around had a nut welded onto the top of the seat truss that you could screw a bolt into that would act as a stop for the flap lever.  I believe Doug's picture is of a Kitfox, but the Avid is built very similar in that area.  Here is a shot of a MK IV Avid getting the seat truss strengthened.  See the 1/4" nut and bolt on the top center of the seat truss.  Jim Chuk

What Ed said!  There are literally thousands of Avids and Kitfoxes flying using the flaps in the original mixer setup.

Fly the airplane.  Try it out at altitude to see what you have.  Set up an adjustable stop like in Doug's photo (if needed!) and you are all set.

I don't care who you are, that's funny right there...

(Julie thought so, too!)

Cliff,

     The later model Kitfoxes have differential ailerons - The early models take lots more pedal work to counteract the yaw - these planes had lots of hours flown before any improvements.

Good Flying,

EdMO

Thanks for the info. I always use flaps for take off in my Cessna 180. Our kolb does just fine without them and many other light planes that I have flown such as Champs, Luscombes, and T-craft don't have flaps. I just figured that It wouldn't much matter if they were dissabled but, your reasoning makes very good sense. I will limit them to 15% which is better than 0%. I have a know it all at the airport that tells me we will die if we fly this thing without the mixer modification, It always helps to look for a second opinion. Thanks again.

Happy B'day guys, I made you a cake. ;-)

Leni,

    I wasn't saying that anyone was wrong - I just wondered if the TCDS on every plane lists the wing rib profile - I had never searched them for that.  Sorry if you took it different than what I was trying to say.

EdMO

It's 15 degrees max if you don't have the f7a. And this came from across the pond as a possible issue, not from this side of the ocean. If I remember correctly, one of our members in the recent past made a bunch of the f7a kits and was selling them. I have as much flap as I can get now and my limit is the control horns hitting the turtle deck, and I have never felt a hint of reversal. I darn sure wouldn't be so scared of it that I disabled the flaps. Not only will they get you off the ground quicker, but they will help for minor trim in flight and if you watch the gps you would be amazed at how small of a deflection up or down will make you loose 5+ MPH. I like to set them in the air where I have the least resistance to roll input. You can get a heavy stick feeling real quick with only a couple degrees either side of the optimum position.

I don't need a tcds to tell me what I know first hand from working with a wing manufacture and limited involvement in subsequent testing and certification on the Yankee cub. I had the original drawings and subsequent updated drawing to study. A quick Google search will net you a whole lot of hits that state the USA 35B.

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Just add a simple stop to limit deflection to 15* degrees max. Pic shows one option, more good info on control rigging and reversal in this thread: http://www.avidfoxflyers.com/index.php?/topic/595-kf-iii-rigging/

Because I didn't know you could do that. What is the proper procedure to do so? How much travel can you safely have? 

Over 7 months since last post in this thread. Is there any update on the status of Airdale?

Congrats on your new toys Colonel, you got one hell of a bargain IMHO! Russ talked me out of an extra set of door latches to use on that plane, I think he still owes me a beer though...

Why make flaperons totally ineffective when you can easily limit travel to prevent reversal?

Well I read it on the internet, so it must be true... 

Luke,

    I thought that there were two different ribs used on the Cubs - but thought the change to the 35 came with the late J3 and for sure on the PA-18 SuperCub.  I didn't know what Taylor used.

    I wonder if the rib type is listed on the TCDS for each plane?   I never checked them for that.

Thanks,

EdMO

Mark.  I meant it to say that the flaps were in the up posistion not the handle.  The handle will be secured in the level flight posistion.

Ed, I remember looking this up one time and one person on a forum somewhere mentioned that lots of people assume that the cubs have the Clark Y because it looks so much like the USA-35B. That must be accurate because I did a quick google search and found this quote from Flying magazine.

 

Taylor chose the lightly loaded USA-35B airfoil for the E-2, a design that provided good low-speed flying qualities — it was reluctant to stall and provided plenty of warning before it did. All Cubs, including the J-3 and Super Cub, have used this same airfoil shape. For this reason, the Cub is a forgiving airplane in the hands of a novice and downright divine with a skilled pilot at the helm.

 

Read more at http://www.flyingmag.com/aircraft/pistons/piper-cub#TQ6rMDEBjmJp22h4.99

Edit: Flying doesn't mention it, but I read in other sources, they mention that some cubs used a USA-35B (modified) because they added 4% to the top surface ordinates.

Unless I'm thinking wrong, you'd want to wire the flap handle down.  Pulling the handle up moves the flaperons down to act like flaps, and is when the control reversal might happen.  Down is the 'no flaps' position.

Mark

Thanks Leni,

     I knew Piper had changed the rib design after using the Clark Y - but guess incidence made the difference.

EdMO

No.... before john stoner died, he was building the ribs for Dakota cub at his hangar in soldotna. I spent a good bit of time with him there going over some drawings they had, one of them being an overlay drawing of an 18 fuse over the 12 to show the difference in the aoa. They both use the USA 35B airfoil.

The early model Avid that  we are rebuilding doesn't have the flapperon mixer upgrade to stop the controls from reversing.  We were going to wire the flap handle in the up possistion to keep aileron throw at it's fullest and keep them from reversing. We have Kitfox 3 wings with droop tips and we don't plan to operate off of short strips. The Kitfox wings are a couple of feet longer than the original avid wing. We will basically be using the plane to fly local only for fun. no long cross countries. Our Kolb Twinstar doesn't have flaps and we seem to do just fine. Are the flaps really that important on an avid considering the way we are going to use the plane? Should we look into upgrading the mixing system?  If we should upgrade the mixing system, where can we get the parts now since Brent isn't answering his phone? Will wiring the flapperons in the up possistion eliminate the chance of aileron reversal? We are getting very close to being ready for taxi testing and we would like to hear your input. Thank You.

Ps, How do you use the spell check?

Leni,

     I forget where it was posted, but you were comparing the PA-12 cruise with the slower PA-18, and talked about the change in incidence:

I don't have documentation on this, but I believe the PA-12 had the Clark Y ribs, like the J3, and the 18 was changed to the NASA (something) 35  or one of the NASA Dud patterns - This could be why the 18 was slower in cruise even with a lot more horsepower?

EDMO

Off the top of my head the axle moves forward 6". Tri gear mains put the axle 1/2 between the gear mounting points and the tail dragger gear puts the axle directly under the forward mounting point. I think the span between the 2 mounting points is 12". Bryce