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Flaperon's

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Hey guys,

 

I'm thinking about turning my elevators into flaperons on my Austflight wb503.

 

I understand there used to be a kit available from Austflight for this, firstly is it still available and secondly if not, can anyone fill me in on how it worked? If I cant acquire one I have a few ideas as to how to manufacture one, but I would rather stick with the tried and proven method if I can find out what that was.

 

 

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Why? You don't have stall speed problems and you would already have enough adverse aileron effect, and plenty of drag . This mod will make it worse. It is an idea that seems good till you try it or think it through.. I have been involved with taking it off a plane that was originally fitted to. It flew much more controllably and the later factory ones were eventually modified too. I'm assuming you mean ailerons.. Nev

 

 

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I hope you mean Ailerons Timbo!!! hahaha. From what I have heard over the years they (the seperate flap/aileron config.) is an unnecessary addition to something like the Drifter ....But keep us updated on your decision I'd be interested to see what difference they make and how you'd go about desiging them.....

 

 

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Flapperons are useful but no so much on the drifter as it has a great stall speed and short field capability. If anything do some short field landing practise. If you want to change something, I would condider changing the ailerons to 2/3 aileron and 1/3 flap, but good luck and let us know how you go.

 

 

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Since Timbo is like me and enjoys his slow flying and general loitering as well as using his plane to get quickly from A to B, the conversion to flaperons would be a great benefit at both ends of the speed scale. The Drifter has plenty of rudder authority so the adverse yaw with drooped ailerons is a non-event to anyone who doesn't have dead feet, certainly no different from a Foxbat for example.

 

The benefits, disregarding the only marginally improved short landing performance (since in the right hands the Drifter can already be dropped on a dime), is the considerably slower loiter (for checking the size and quantity of the fish in the waterhole) and also the much faster and more comfortable cruise if you set the flaperons to be able to provide 5 and 10 degrees of reflex as well as the, perhaps, 15 degrees of positive flap effect. I experimented with my Drifter years ago and set the ailerons with 5 degrees of reflex, it made the takeoff and landing rather long and faster but I got a cruise of over 60kts compared with 52kts with the standard setting. Having discovered that I had a plan to convert mine to flaperons but it got overtaken by other events.

 

All you need is a relatively simple mixer system but it does need to be built well, if the existing Drifter one works OK it's best to stick with the proven design but if you end up needing a hand with a new design you can give me a hoy if you like.

 

 

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Dazza, Justin's Drifter has flaps and ailerons, not flapperons.

 

 

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sorry guys! I cant believe I wrote elevators! this is what happens when you try and squeeze out a post when your partner is trying to get you out the door for a dinner date!

 

HITC is 100 percent correct, though the other reason is I want to experiment with improving the takeoff performance. see if I can get them down at that last minute and get the wheels up that few meters earlier. All in all i just want to experiment a bit with the drifter to see how good a bush plane I can make it.

 

Wayne was helping me come up with some ideas for a great little bush plane drifter to build next. So i thought now i wont be building that aircraft with him, I would experiment with some of the ideas on my own.

 

regarding the 70 / 30 flap aileron, thats the other option im looking into, but for experimentation sake, this will be alot easier to achieve

 

 

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I like the idea of being able to reflex them for a few extra knots. 50kts can get a bit tedious especially with a headwind. Interested on your progress tim

 

 

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Yes, I've seen one before, it was a while ago and integrated into the engine mount for the 582 IIRC. Facthunter has obviously had more to do with it though since he removed one, perhaps he could describe it?

 

 

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The plane involved wasn't a drifter. It involver a major redesign of the control and.trim system..Nev

 

 

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Interesting that Ole at Australian Aircarft Kits (AAK Hornet Manufacturer) dropped the flaperons on the Hornet in favour of separate flaps and ailerons. I think the Foxbat is one of few remaining flaperon fitted AC these days.

 

 

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I wont lie, I would rather the flap/aileron setup. still with reflex like a Maule. Wayne and a few other people however have just told me how simple a modification is on the drifter given the linkage method used on the aircraft and I just thought this may be a very simple way of getting that little bit extra performance.

 

As I said, its not really landing im worried about. I have a reasonable amount of STOL experience and can get the aircraft in some fairly tight spots, and can get it out again to no worries. I would just like to see if this mod will help bring the Takeoff performance in a bit closer to the landing performance. also to if reflex will successfully give me that bit extra cruise speed, what a great addition!

 

 

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More power is the best way. As you say the linkage on the Drifter can be easily adjusted. YOU may well be able to fly with a lot of adverse aileron but that can require more rudder effectiveness which you may run out of. The plane in a tight (gusts) situation will be harder to control, as you lose some or all of the differential aileron effect by having the aileron go down only. ( Down and further down). In reality I can't see the ground run and lift off distance being much better than with the wing clean and just hauled off a bit earlier and flown in ground effect till the safe speed is achieved. Low level power failure at slow speed isn't going to be helped much by having flaps on an already low inertia draggy plane. You would probably do better with VG's. Nev

 

 

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see this is why I come on here! cant beat knowledge from experience! and you hit my other thing I'm researching! VG's! A few people have said to me that given the shape of the drifter wing (being ribbed and not flat) that VG's wont really work. however my understanding of VG's (and this is what I'm looking into now, is homing that understanding) is that that's not how the really work. I am waiting for a few of my bush flying mates in Alaska to get back to me RE there views on it, as they already have extensive experience with them, though if there are people over here who could fill me in with an unbiased view I would really love to hear! would they work on a drifter wing and would they mount ok onto the fabric? As this would be the very first thing I want to try well before flaperons (they was a down the track idea anyway)

 

the take off method you mentioned Nev is exactly how I fly it, wheels off as early as I can to reduce drag while floating in ground effect and increasing speed as high as possible as soon as possible to be ready for a fast climb out for the first couple of hundred feet. Though I was hoping that the increase in lift may help get those wheels up that little bit earlier so I can work them with my ground speed to see if I can shorten the distance of that process. I have done it alot in other aircraft with standard flaps and a substantially more powerful engine (thats going back to the power thing you mentioned nev) and also like you said I have a feeling that the power on the 503 wont be great enough for it to really work effectively, though I just thought it may be worth a try. of course the other consideration is going to the larger engine, but From Waynes experience he felt that despite the the extra power of the 582, the extra weight is still going to keep you on the ground a tad longer anyway, and I know from experience that the 912 on the back is even worse again, the ground roll was quite a bit more than my 503.

 

 

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Rather than worrying too much about theories, the easy way to experiment with it and get some real data for comparison would be to make up a pair of shorter aileron pushrods and compare the performance and cross-wind capability. I don't buy FH's argument about crosswinds being a reason not to have flaperons because if the cross-wind component was that strong and you felt you had any problem holding a wing down you could always choose not to use the flaps (or should I say 'lower the ailerons'?). The flaperons simply add a dimension and hence more flexibility, just because they're there it doesn't mean you're compelled to use them for every landing and/or in every situation.

 

Differential aileron effect is the effect of the up-going aileron's deflection being of a greater angle than the down-going aileron's deflection and I can't possibly see how that would be changed, adding a mixer isn't going to change the Ackerman angle of the original installation. I can't imagine how having both ailerons drooped is going to affect the amount of total rolling force compared with not having them drooped, and it's the rolling force which keeps the windward wing down, not whether the ailerons are collectively drooped, centred or reflexed.

 

I've landed Drifters in some pretty severe crosswinds and never run out of rudder, as long as you don't let it get away from you in the first place I don't see how you could ever not have enough effectiveness. We're not talking about engine failure here, a burst (a trickle even) of power provides an immense amount of response from the rudder, it being so close behind the prop. I'm not sure if FH meant me or Timbo when he said "YOU may well be able to fly with a lot of adverse aileron ..." but it wouldn't worry me because I experiment with the boundaries of the envelope and I'm certain it especially wouldn't worry Timbo who was trained by Wayne Fisher aka 'God himself' where Drifters are concerned.

 

 

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Geez I wish some would read what I actually say. I said GUSTS. A totally different situation. . Happy to answer for what I write but not what I don't write . I make a big effort to be specific. Nev

 

 

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...I'm researching! VG's! A few people have said to me that given the shape of the drifter wing (being ribbed and not flat) that VG's wont really ...

The adhesives used with VGs will stick to pretty much anything, so fabric is not a problem. (Beware acrylic paint, though. Not much will stick to it.) The variable surface of a fabric wing should still benefit from the delay in airflow separation that you get from VGs. My experiments show the stall is reduced by 2 or 3 knots. With my wing, VGs have turned a distinct stall into "mushing" thru the air, losing about 700 fpm.

 

 

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was that on your jodel? and did you find it difficult calculating the best positions for them? lastly did you find any decrease in cruise speed after there installation? people seem to be saying they didnt notice a difference at all, or the difference was a good few knots, so one extreme to another. I start to wonder if that is due to installation

 

 

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They have been approved on quite a few larger GA planes. There is not generally a loss of speed. It usually improves. You can't guarantee every application will do this because there are too many variables, but the principles are the same. Nev

 

 

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was that on your jodel? and did you find it difficult calculating the best positions for them? lastly did you find any decrease in cruise speed after there installation? people seem to be saying they didnt notice a difference at all, or the difference was a good few knots, so one extreme to another. I start to wonder if that is due to installation

Yep.

 

Nope; follow the instructions.

 

Haven't finished testing, but so far no noticeable impact on cruise.

 

 

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Had flaperons on my Zenair 701. Lots of aileron authority for little deflection and the wing wouldn't stall even after the pitot and rudder had no authority left. That said, there are lots of variables for our little planes and I don't know how rigging a Drifter for a pair would work. A slightly lower stall speed would be nice but not essential. A wire braced Drifter has enough drag to land easily in any field you can safely take off from.

 

 

  • Agree 1

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