Sounds good in theory,,,

Two hurdles:

1.  Getting a 1/2A engine to throttle properly.

2. Scaling down the 3-line bellcrank.

Any proposals?

          We have been looking at putting two Sig 1/2a bellcranks together to make a simple 3 line system, there is another experiment that we are working on with line and a spring but that does not seem to be practical. There are several 1/2a engines that throttle pretty well, another option might be a simple fuel cutoff with no slow speed laps. I like the slow speed laps so I lean towards throttled engines.
Larry

Now all I have to figure out is how to make it big enough to see. 

7-18: I think this one looks OK.  This is as supplied in an MO-1 kit.
The hook sticks thru the fuselage, dowelled and bushed, with a wheel collar on the other side.
The about 1" coil is the spring to hold it down.
The trip wire originally went through a bushing, but that broke off during use and turned out to be unnecessary.  Full down releases the hook.

I agree with Pete about the size of the plane being difficult. I fly both 36 profile and 15 carrier and the plane is much harder to fly than the 36. For most the full sized profile would be much easier to learn on and get to enjoy.

I think the old WAM 1/2A did have some throttle. The Cox motors back then had an exhaust baffle/ring that was operated by the third line. The extra line exited the model near the tail and that helped pull the tail in and the nose out for hanging. As I remember there were some very good fliers that could pretty much hover the airplane around the circle. It was interesting to watch. Never flew it myself. With the aft mounted line the line tension would be minimal and make it extremely difficult to hang the airplane.

Larry: I think that it's great that you are proposing doing something positive for the event rather than just lamenting the passing of the good 'ol days.  My concern is that the plane you propose will be difficult to successfully fly at low speed and discourage possible converts.  I know I had zilch luck flying 1/2A WAM (on a borrowed plane) - one flight was enough to convince me to stay with my 36 sized planes.  The only way to resolve this is to design, build, and fly the plane - and see what happens - wishing you great success with the project.  

bfrog is correct, WAM 1/2A carrier did have some throttle input.  The third line went from the exhaust baffle, around the tail and to the handle.  Two handles and both hands were used, one for elevator, a second for the tail/throttle tweaker.  I really don't think it is the way to go here.  Very difficult to do successfully and a little too much like a "puppet plane" for me.  Spectator appeal was minimal as the airplanes pretty much hovered around the circle with their Tee-Dee and Medallion engines screaming at almost full throttle.  Noisey, irritating,  many crashes.  That was one reason it died out.  OK Cub engine would not have enough power for this type of flying.  A standard 3 line bellcrank set up would be preferable if it could be made to work and the airplane could be made reasonably easy to fly.  Tall order.  FWIW: WAM profile carrier was flown the same way, .40 max engine size, two handles etc.   Prop hanging was the norm well before it became incorporated into the AMA event. 

Just a thought:  Enlarge by 10% and you are getting into .15 carrier numbers.  Might be a way to go - R/C .15s are available, better fit for currently available bellcranks and handles, a competition class should you want to go that route and a good training class for the other carrier classes. If fun only is the goal, certainly other sized engines (ie:.09,.10)  could be used. Suggestion Larry - design a 1/2A size and a 10% larger .15 size and have a fly off.  Best beginner plane wins.  My pet beginner idea is to steal a cue from the racing guys and propose a Goldberg (maybe OS-Berg) Carrier Class...but that will be the subject of another thread when I get around to it.   

        For the table top models You should try one of the new reed valve engines from OK they are really very good, better than the 'A' engines that we were selling.
Larry

AIRFOIL:  We have been working with a symmetrical airfoil and planning to make it thicker but maybe I should be looking at a flat bottom airfoil?

What do you think of these: Seafire (carrier version of the Spitfire), Zero, Helldiver, and Hellcat.
Larry

Gotta get another 2 cents here - Thin air-foil, design optimized for "hover" flight is the way to go if...the goal is to produce a competative .15 carrier design.  Heck, just get permission to kit Bill Bishop's "Sniper" design  - not a bad idea, actually.  But, if the goal is to produce a more versatile design, one may want to consider a fully symetrical airfoil - and a more attractive design.  Regarding the airfoil, a medium thick symetrical airfoil would give the modeler (customer) the option of building a carrier plane or... a sport/stunt trainer.  This would broaden the appeal of the design and     who knows, maybe the plane will foster another racing class. 

As far as carrier flying goes, it could still be competative at the level of its target market, beginner or intermediate carrier.  Personally, I would de-emphasize the "hover" flight aspect for the beginner.  Let them fly fast, fly slow, and learn to make a scale type carrier landing. Not that difficult and a very satisfying maneuver.  My son was WAM junior champ (twice) when he was 13 and 14, only event he flew was profile carrier but made every landing using this style of flight.  Later, the leadouts could be moved back and a hover style developed - after interest in the event was developed.

Regarding the choice of designs:  I'd rule out the Spitfire and Zero.  Love both of them but they are pure low wing designs.  Mid wing, shoulder wing, and even high wing are more stable in low speed, probably having to do with the vertical CG.  OK, the Helldiver and Hellcat are not exactly mid wing but the wings sit higher in the fuselage than the previously mentioned designs.  Also mounting the wing through the fuselage rather than gluing to the bottom makes a sturdier wing mount.  Of the H-Cat and H-Diver, I prefer the Diver, only because it is rarely modeled but the Cat might be more attractive to a beginner modeler and, squared off wing tips (Cat) are easier to build than rounded tips (diver).

Reading this post over - I was thinking .15 when I wrote it, but most of everything would apply to 1/2 A as well.

OK so I am getting a picture here...I think I am ready to order in ribs. I am looking at putting the bellcrank outside of the wing and locating its mount so that it can be placed on either the right, left or center of the wing...up to the builder. This should make hooking it up and adjusting it easier.
Thanks 
Larry

We will probably make 3 or all 4 of these at the same time.
Seafire (carrier version of the Spitfire), Zero, Helldiver, and Hellcat
They will all be very similar to one anther and use the same plan. They will also fit into our war bird series. I know....low wing....but that is what we are using on our current war birds and a couple of these new ones were designed by Walt Musciano(without the carrier stuff)
Larry

 H^^now if blackhawk could make a real nice looking plane  that would be great