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CL model towing a glider?

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Old 09-23-2010, 07:18 AM
  #1
Avaiojet
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Default CL model towing a glider?

OK, call me crazy I don't mind, so here goes.

Has anyone ever pulled an airplane that had no power source with a CL airplane? Like a glider.

This would mean that the tow airplane would be controlled by another pilot. Both airplanes on different lines.

Pilot and one set of lines for the powered model and another pilot and lines for the tow plane.

I see no reason why this cannot be done?

Thanks,

Charles

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Old 09-23-2010, 08:47 AM
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Default RE: CL model towing a glider?

There was a construction article - long ago ( '70's ????) - for a scale Control Line Army Airborne glider. Don't remember the mag - probably FM or MAN. I always wondered "Why?" ...
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Old 09-23-2010, 12:28 PM
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Default RE: CL model towing a glider?

I have seen it done at the Brodak flyin with a Curtiss Commando tow plane and a Waco glider (IIRC). I have no details.
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Old 09-23-2010, 03:51 PM
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Default RE: CL model towing a glider?

You know the arguments about locating the CG for pitch stability and how lethal a CG can be when too far aft?

Consider the problems you'd encounter with something attached to a CL model. Whatever the item, a banner or glider or such, is going to encounter the same centrifugal forces the tow plane encounters. If the glider is on lines, then that problem is partly solved. If the glider isn't, then maybe the glider needs to be R/C controlled if only to trim it to fly around in circles with the least problems for the tow plane. In either case, the tow line probably should be attached at the Neutral Point of the tow plane so it'll cause the least steering effect.

I'd think the most important problem to solve would be how to get the glider/banner to track with the least effect on the tow plane.

Experience with R/C planes towing gliders convinced me to go instead to cradles for the power plane to carry the gliders aloft. You can't imagine how badly the glider pilot can affect the tow plane if the glider pilot doesn't know what is required and can do it. And setting the gliders trims so it could be towed without a pilot's input really doesn't seem possible to me. And that's possibly what some might want to do for this CL deal.
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Old 09-24-2010, 04:44 PM
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Default RE: CL model towing a glider?

Avaiojet Certainly go for it. I beleve it is entirely practical with a double controlline pilot setup. Mixing RC and controlline for the two I feel would be a mistake.

I have done considerable RC aerotow on water and land as well as both ends of the towline but not this and its definately an exciting challange. Indeed the question as to why is simple 'its the challange' Composite cradle launch is a bore, Aerotow is very cool.

Dang this is exciting, heck I even have a Waco PG-1 which was the one off twin engine version of the CG 4A troop glider. I flew it a bunch as an RC airplane with a couple of 15's untill I got bored with it. This would make an easy conversion back to a glider and controlline. OH man now I need a C-47. bet that top flight kit would be a perfect conversion.

I hate it when on these aerotow gigs I always somehow end up building/converting both ends. I wished you lived near AJ. Anyway you are not crazy and its a perfect challange, is doable and do not let anybody talk you out of it even if you have to do both ends of the tow line and train a pilot for one end or the other

John
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Old 09-27-2010, 07:46 PM
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Default RE: CL model towing a glider?

John,

Is that model a kit!

The tow thing?

The biggest issue would be keeping the lines tight. This could be enhanced by connecting the tow line to the port side of the fuselage? Instead of in the center.

I'm thinking about this line issue.

Charles
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Old 09-27-2010, 10:05 PM
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Default RE: CL model towing a glider?


Quote:
ORIGINAL: Avaiojet

John,

Is that model a kit!

The tow thing?

The biggest issue would be keeping the lines tight. This could be enhanced by connecting the tow line to the port side of the fuselage? Instead of in the center.

I'm thinking about this line issue.

Charles
Now that's an interesting idea.

It wouldn't be scale, but if you figured out where the glider CG was in all 3 dimensions.......................... hmmmmmmmmm........ But you've also got aerodynamic drag to "pull", not just weight........ hmmmm
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Old 09-27-2010, 10:51 PM
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Default RE: CL model towing a glider?

Quote:
ORIGINAL: Avaiojet

John,

Is that model a kit!

The tow thing?

The biggest issue would be keeping the lines tight. This could be enhanced by connecting the tow line to the port side of the fuselage? Instead of in the center.

I'm thinking about this line issue.

Charles



No Charles it was published in an old flying models mag can,t remenber its date in the seventies but was smaller and intended for .074's and I built it from those plans.

My own speculation would be that keeping it on the lines may not be as big an issue as you think , perhaps skewering the thrust line (towhook) just a small amount inboard a small amount as you suggested, but of course I have not done it. Please keep the project alive and posting about it here.

I want to attempt it so bad but I am the only one here flying any controlline so that can be very frustrating.

John
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Old 10-01-2010, 01:05 PM
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Default RE: CL model towing a glider?

Back in the 1948-50 era of Control Line Precision Aerobatics, there was a separate 'special maneuver' which was up to the flier. I Know banner pick up and tow was done, and I think glider tow as well. I would't have control lines to the glider. Maybe just some sort of relaese mechanism.
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Old 10-01-2010, 02:28 PM
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Default RE: CL model towing a glider?

I would have loved to see that Jim, no doubt very cool. Also would have loved to see some of the carefully calculated pubic stunts that Jim Walker became so famous for But alas it was not to be.

Fortunately I was able see many of the cool flights by the gentlemen from Cox at the circle in front of Tomorowland at Disneyland in 56 and 57.

So how about it Avaiojet gonna give it a go?

John
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Old 10-01-2010, 05:25 PM
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Default RE: CL model towing a glider?

Ifound it!
Iwas sure I'd seen a treatise about flying a glider towed by a U-Control plane and it turns out it was in a book Iown and have had since the 60's. "Building and Flying Scale Model Aircraft" by Walter Musciano (of course) has a WACO CG-4A glider set up for pick up and tow. The book is still in print and can be had from Amazon.com for about $7.00 It's a great classic and should be on the modeler's shelf.
The model has a fuselage with sheet sides, bottom and top, wings with moderate dihedral and usual rib, leading and trailing edge construction. A trapeze affair over the nose and projecting forward provide the catch point for a hook trailed behind the tow plane.
I'd copy the plans, but I'm pretty sure I'd be busting some rules, just be assured that it has been done befort and worked.
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Old 10-01-2010, 06:22 PM
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Default RE: CL model towing a glider?

So for the 64 thousand dollar question, is the towed Waco also controlled with controlines by a second pilot?

John
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Old 10-01-2010, 06:48 PM
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Default RE: CL model towing a glider?

The towed glider is just in trail, no pilot. Isuppose you could try to do it with two pilots...sorta captured combat style.
The method described in the book actually has the powered plane do a "pickup" by having the tow line for the glider held about 8' abover ground between two bamboo poles.
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Old 10-01-2010, 07:32 PM
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Default RE: CL model towing a glider?

Thanks I can just imagine how long free flight tow on a controlline airplane would last but still very cool. That probably explains the bridle harness for an airborn snatch.

Oh, man don,t do it bucky controll yourself Think I would be inclined to do it with two controline pilots and no snatch departure but a towed take off.

John
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Old 10-01-2010, 07:39 PM
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Default RE: CL model towing a glider?

Go for it!... Let us hear the story and see the pics!
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Old 10-01-2010, 07:46 PM
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Default RE: CL model towing a glider?


Quote:
ORIGINAL: BtnFlyGuy

I found it!
I was sure I'd seen a treatise about flying a glider towed by a U-Control plane and it turns out it was in a book I own and have had since the 60's. ''Building and Flying Scale Model Aircraft'' by Walter Musciano (of course) has a WACO CG-4A glider set up for pick up and tow.

Would you be so kind as to scan the article and see what, if any, trim settings Walter suggests for the glider. How does he suggest keeping it in trail?

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Old 10-01-2010, 07:46 PM
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Default RE: CL model towing a glider?

The dihedral has got to cause a roll when yawed, and left yaw is what the glider will see as soon as the towline tightens up.

Heck, maybe it stabilizes with the towline tangent to the circle or some other surprising result.
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Old 10-01-2010, 08:39 PM
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Default RE: CL model towing a glider?

Rock,
Ican't send yuo the article because it's an entire chapter in the book, but most of the idea can be figured out from this diagram (probably illegal). The plane can also be flown as a hand launched towline glider, hence the two launching hooks on the bottom and the 100 foot launch thread.
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Old 10-02-2010, 08:43 AM
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Default RE: CL model towing a glider?

Quote:
The dihedral has got to cause a roll when yawed, and left yaw is what the glider will see as soon as the towline tightens up.
Yes, I agree.

There's absolutely no way a towed model will stay stable without control.

My guess is it would corkscrew like a kite. The second pilot is necessary as is the lines.

I'm saving that glider drawing, thanks for that.

With my software, I can scale drawings easily. I only need the outline to build, so I do a perimiter trace and enlarge the drawing to any scale. My cutting machine will hold a special pen. Acts like CAD.

I traced the Tiger Shark plans and enlarged them so I would have a 72" model. I used an Astro Hog wing but made many changes to it. This was for RC. I may CL it now.

I did have a Thread on the Tiger Shark, but the R/C guys didn't know much of it, or have real interest.

Here's a photo or two. You can see the Tiger Shark fuselage on my old bench.

Charles
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Old 10-02-2010, 09:59 AM
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Default RE: CL model towing a glider?

I bought one of the Stanzell Tiger Shark kits that were original kits repackaged four or five years ago. Could not resist buying such and old kit from the orginal producer in new boxs and perfect condition for so little, it was a hugh attraction, could not resist.

On the plans in mine it shows the installation of the G line system and a fellow flying it with a bamboo pole. Also shows articulated rudder and elevator with a rubber band system to make them stay in place and remain adjustable.

John
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Old 10-02-2010, 10:59 AM
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Default RE: CL model towing a glider?

John,

Great to hear about your TS.

Even though I go way way back, I never could understand or had it explained to me how a CL model could fly on only one line.

Or have I got that wrong too?
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Old 10-02-2010, 11:12 AM
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Default RE: CL model towing a glider?

With the modern monoline, developed by Stanzel, a solid line is twisted to give control. It never became greatly popular except for speed. However, I have seen Joe Kirn (Dale's son) fly a very reasonable Old Time Stunt pattern with a monoline airplane. If you are ever in Schulenberg, TX, be sure and visit the Stanzel Museum.
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Old 10-02-2010, 11:39 AM
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Default RE: CL model towing a glider?

I have never done any form of monoline myself. The Stanzel G-Line as depicted on the Tiger Shark kit is not the same as Stanzels later mechanical Monoline system that actuates the elevator by twisting the single line.

G-Line did not actuate the elevator instead the airplane was controlled on a single line with the pilot wielding and eight foot bamboo pole with the prescribed length of line from there to the airplane.

Key to the operation was that the line did not connect to the airplane in what became the normal CG relationship as did Monoline or U Control. Instead the line attached well forward of the CG somewhere between the firewall and the leading edge of the wing and this was done with wire standoffs in front of the wings leading edge.

Also with G-Line the rudder and elevator were articulated (hinged) and at the juncture of the elevator and rudder was a simple wire sliding device at the surfaces trailing edges that used a rubber band to hold their position. This to make small adjustments with.

I have not flown this way but just describing what G-Line was. I beleve it was the first system the Stanzells used in defiance of the Jim Walker patents.

John

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