I will try to go through several possibilities that I can find that can satisfy the 5 requirements listed:
1. Must be able to use the two OS .25 FP engines
2. Semi-scale
3. Profile
4. Stuntable
5. Classic Legal.
The choices are rather limited some will be performance challenged. I am listing all of the twin "semi-scale" stunt ships, some have full fuselage, and some are not Classic legal.
Jim Kraft mentioned Bob Adair's F7F Tigercat. This has been flown at VSC by Jim Hoffman from Phoenix has made a credible showing with it. He uses two OS .15's. The use of two .25's would be a bit of overkill and the increased weight of the .25's would not help performance regarding "stuntability", at least in terms of doing a credible pattern.
Claire Sieverling did a provile of the North American A-26 Invader, Model Airplane News, July 62. Kind of smallish, even for the two Enya .19's he used. Flew at 85 mph. Thin wing section of probably less than 15%, no flaps, about a 42" span, fairly high aspect ratio so the area is not that great. This one would be pattern challenged.
Jack Sheeks did a full bodied version of the Curtis AT-9 Jeep, Flying Models, 1976. Designed for stunt and two .30's, the OS .25's would work fine, but not Classic legal.
Paul DelGatto did a full fuselage/nacelle version of the B-25 Mitchell, Flying Models, Feb/Mar 63. This was designed for stunt, thick airfoil, flaps and appropriate moments. Designed for two .19's, but 25's would not be too far out of the question because this is a "reasonable. About a 52" wing span and something over 400 sq in. LeRoy Black from Phoenix has flown one of these at VSC and it makes a respectable presentation with it.
Jack Sheeks did a version of the deHavilland Mosquito as a semis scale with "full" (albeit slimmend down) fuselage and nacelles. Used 2 .35's, but the OS .25's would be more than enough power for this. This one can be built for serious stunt competition, but its published date is August 1981 Flying Models sort of knocks it out of consideration for Classic competition. An RSM kit is soon to be available if not already released.
Jack Sheeks did the Grumman F5F-1 Skyrocket for stunt, Flying Models, Aug/Sep 63. Full body fuselage and nacelles, a good sized airplane for stunt, good airfoil and moments. Had two Fox .35's, but the OS .25 would substitute quite nicely. I-Beam wing. This could be one of the better twin semi-scale ships that is classic legal.
Joe DeMarco did a Heinkel He 219 in Flying Models, May 74 for two .15s with a 39" span. this would be kind of small for the two .25's. Really thin airfoil, but a really neat looking model. (Actually, this thing could be flown for Mike Keville's 1/2A profile scale contest with two .061s and would fly just fine for a scale contest.)
Steve Ashby, who is a really good scale builder and has been on our US Scale team a number of times to the World Championships, designed a semi-scale stunt version of the Messerschmitt Bf 110, Model Aviation, June 1980. Near scale fuselage and nacelles, flaps and a lot of area Used two OS .25's.
Aeromodeller published two twin profiles in the Dec 72 issue. One was the D.H. Mosquito and the other was the Me 110. Kind of small, had flaps, on a fairly thin wing section. Designed for .15's to 20's. Probably not Classic legal.
Lew McFarland's P-38 has been mentioned, American Modeler, Sep/Oct 66. This is not a profile, but is designed for stunt. His had two Veco .19's. 56" span, 475 sq in area. Nice airfoil with flaps. Flaps are built up as in integral part of the airfoil and are not a sheet added at the rear end of the airfoil as most stunt ships do. Kept light, this one has a lot of potential for a Classic twin scale stunt ship.
I have some plans for several twin engined scale airplanes from the 1940s that surprisingly have fairly thick and symmetrical or near symmetrical wing sections. These were designed by Paul Plecan and include the P-38, The F7F Tigercat and the Westland Whirlwind. They are not profile and build into a decent looking scale airplane. These are the plans that Bob Whitely used for his P-38 that he flew in OTS at last year's VSC and Chris McMillin used for his Tigercat, also at VSC last year. These are really a bit small, even for .15's and their wing loadings are a problem. Both of these models were definitely challenged, even for the OTS pattern. The Whirlwind would not do much better, but I intend to try one for VSC in 2009.
There may be more semi-scale twins that might be considered for use in the CL stunt circle, but these are the ones I found in my files after a quick look. I have not intentionally omitted anything from this list.
Keith Trostle
Topic: Here's a tough one... (Read 2338 times)