I was wondering whether any of you chaps has flown a R/E model with flaps. If you have, were there any problems with that set-up?

The reason that I'm asking is that I want to build a large-ish Southerner to use as a glider tug ... towing vintage gliders. I'd like to keep the Southerner as authentic as possible, but it will definitely need some extra glide-path control; hence the flaps.


[link]http://www.flairmodels.co.uk/Aircraft/Ben_Buckle/Images/Southe50.jpg[/link]

Flaps require a strong wing structure that resists their twisting effect when deployed.

It seems that the structure of the wing of model in the picture resists little in that direction.

You could try fixed flaps that can be removed at will, avoiding all the mechanisms and anchoring them to the fuse, liberating the wing of some stress.

Check the attachment for additional information.

Oh, don't worry, I'd create my own wing structure ... suitably stiff.

I should have made myself more clear; when I said that I want authenticity, I meant "authenticity of outline, rather then of internal structure.

I'm anticipating a model of around 96", with two-piece wings and a decent four-stroke in the nose (Enya 1.20R, most likely).

On reflection, I can probably answer my own question. I mean, I know that glider-guiders use R/E in conjunction with flaps, so it shouldn't really prove to be problematic in this case.

Bob I do have considerable experiance with aerotow and at both ends of the towline. I have flown many tows with R/E gliders and found that is a challange that never looks very pretty. Therefore we have always recomended gliders with ailerons.

Now in the case of the tug I have never tried a R/E tug and don,t think that would be a choice I would want to spend a lot of time on and attemting chamber control with the tug is only going to complicate matters more.

I do understand the desire to want to use old timer type airpanes on both ends but a better choice for the tug would be an old time with dihedral instead of polyhedral and reduced somewhat with ailerons. There are many old timers which could fit this bill nicely with just the addition of ailerons.

Actually using chamber control on the glider is an asset that that I have experimented with considerably. I have a Seniorita without engines in this case, that I use as an aertow trainer and has full span ailerons that are also set up to provde chambercontrol. For tow the ailerons are set at full reflex which reduces lift and helps the tendency for the towed aircraft to overclimb the tug and improves the pilots ability to maintain control of the glider when it is being towed. After releast the ailerons are put into down position to provide max lift and the slowest descent.

I wish you the best with your adventure aertow is great fun in itself and something more than just a way to 'get it up'[8D]

John

I don't have too much towing experience ... a few dozen lifts, mostly on the tug' controls. We are currently using a T180 as the tug. This is fine, but it's too small to allow a really high tow - it disappears from sight long before the gliders.

There's just a small bunch of us who are interested in this business. One of the chaps has been successfully towing smal-ishl gliders, using a Junior 60, with a .25 two-stroke. As you might know, the Junior 60 is R/E.

Certainly, my own R/E glider tows fine. The only problem seems to be the launch; but the use of a dolly obviates any problems with a wing-tip digging in.

My thinking is that a tug which has oodles of built-in stability can be flown much higher than a conventional model. There will be no fear of losing control, even when it becomes a speck in the sky. As long as the pilot can see which way the model is headed, he is guaranteed to get it home ... power to idle and extend the flaps. This thinking extends to the glider, too. Apart from anything else, vintage models tend to be good light-weather soarers and I live in a region where thermals are thin on the ground. At least, I can't seem to find many of 'em!

Anyway, it wouldn't take much effort to pop some ailerons on the wing of the Southerner.

Right now, I'm building a 115" Ivory Gull; have just begun to cover the airframe. Nylon and dope (masochist, eh?). http://www.myhobbystore.co.uk/produc...g148ivory-gull.

Our little group began its adventures using an old power model as the glider. Very successful and easy to tow, with a surprisingly good glide. We even tried "heli-towing" ... actually, that simply involved lifting the glider straight up and then popping the nose release. Worked a treat; then he flew off and crashed the helicopter. Ah, well, probably the kindest thing.

You can see our original efforts here http://www.youtube.com/watch?v=WGQ7tU8DylE ... the glider with the Maltese crosses belongs to me.

Cool to see your group of fella's enjoying the Aerotow experiance it indeed is a wonderful experiance in itself beyond just the need to get the gliders up.

One thought on the very real difficulty in maintaining control of both aircraft as you gain altitude is a simple climb procedure we have worked out here and seems to allow us to climb higher.

Most RC pilots will tend to fly in a more or less rectangle pattern which is fine to a point. But we have found that left or right if the tug pilot will start a shallow turn roughly after stage center and never come out of this turn for the duration of the tow that this make thing far easier on both pilots for the entire tow.

This is especially useful the higher one gets when orientation becomes a problem. Relative position is controlled by the tug pilot simply by opening or closing up the turn as neccessary to maintain position during the climb.

This technique also make it easier for the glider pilot use the ability to track just outside the big turn more or less to maintain a good tow tension and avoid whip lash.

Here are a couple of shots of some dollys we use that I make up both land tow and water tow. I also added a link here of a tow using my current tug a Great Planes Stearman towing the Oxy Moron a bashed Seniorita for a aerotow trainer that also serves as a twin engine trainer its a quick change artist.

http://www.youtube.com/watch?v=wwXN8Z2inyo

John

I'll probably filch your dolly design ... it's better than the one which I had in mind for my Ivory Gull.

We did get quite a bit more proficient at the aerotow. Here's me on the tug and my two pals on the gliders... http://www.youtube.com/watch?v=k74EqrITs6E

But, we found it much easier to simply climb straight ahead. I expect we'll graduate to a more complex pattern next year. The problem is that we are "flying blind", so to speak, because there's no-one round here with any practical experience of this art.

Please be my guest Boq, the vid of the double tow is awesome never tried a double tow not even when I was still active in full scale, of course the big problem would be a turn. Seems likely that it may end up like WW11 when the Germans attempted to tow the Me 321 with three Me 110's

This is my current tug the Stearman with an OS 120FS, previously have used a Midwest trainer floatplane with a K&B .45 for the water tows, two different Lazy Ace biplanes one with an OS 1.08 two stroke and one with a G-23 gas engine, and a Senior Telemaster with a Magnum .91FS.

John