Big John (oz2364)
About this Plan
Big John (aka Big John the First). Radio control sports model biplane. Wingspan 76-3/4in, wing area 1,500 sq inches. For .60 power.
Note although Bill Northrop published this design in 1973, the model was designed and flown much earlier, circa 1958 (see article text).
Quote: "The prototype Big John is still this editor's all-time favorite of his own designs. Perhaps you'd like to share the pleasure of flying a big, lazy biplane that will do just about any maneuver - if you don't mind waiting a little while for them to get completed. A great exhibition airplane! By Bill Northrop.
The prototype Big John (BJ the First) came about, indirectly, as the result of our purchasing a set of English-made, 6 inch diameter, M & S Airwheels. This was in late 1957. Being a typical, balsa dust-in-the-hair modeler (the ones who stick pieces of wood together, cover them with something, and then somehow make the whole assemblage stay in the air without visible means of support), we built a model just to suit the wheels, a 3 inch scale Gipsy Moth. We purchased the last completely assembled Forster .99, two speed ignition engine for power (Forster Bros put it together for us from parts and said it would be the last one they'd sell complete). The finished plane weighed just a spec under 15 lb and had wing area that wouldn't quit! The combination turned out to be too much for the Forster, but by now, we were determined to get that engine airborne on something, so we drew up and built the prototype Big John.
Even though it was 6 pounds lighter and much smaller (only 1500 sq in!) the Forster still didn't seem to have the power, and so as with the Gipsy, we went to a Fox 59 in order to fly.
By the summer of 1963, we had acquired a Quadruplex proportional system, and had a real ball flying Big John at various R/C meetings, where it attracted lots of attention. The most often heard comment; sort of a back-handed compliment, was: Gee, that flies real great... for a biplane!
Tell ya what, it's the kindaplane that makes you want to shoot touch-and-go's, tankfull after tank full. It' ll do 3-point or wheel-only landings with equal agility. Aileron rolls are a little slow, but oh, so to majestic. Throw in a little rudder and they're a bit faster. Snaps and spins are easier with the enlarged rudder area, but still not quick and jumpy like a model just slow, realistic, and pretty - like a real airplane!
On Labor Day Weekend, 1963, we joined some pretty noteworthy company at Dahlgren Naval Weapons Lab, Dahlgren, Virginia - namely Maynard Hill, Walt Good, and Howard McEntee. The occasion was the first of many World R/C Record Trials sponsored by the DC R/C Club, and the primary objective that year was to capture the R/C Altitude record, then held by Russia. We brought Big John along for the fun flying between trials, but were convinced by others that we should also shoot at the record. And whaddya know? Big John flew to 7,470 feet; enough to beat the Russians, but not as
high as Maynard (13,320), Walt (10,080), or Howard (9,210). Hmmm. Maybe we should have tried to convince the FAI to establish a record category for R/C biplanes. Don't think it's been beaten yet!
A year later we developed Big John One More Time (oz6522) which had numerous modifications, including many added construction details such as fairings stringers, full symmetrical tail surfaces, thicker wing section, wheel brakes, nylon bolt assembly, etc. This was published in RCM in 1965.
In retrospect however, we still sorta favor the simpler construction in the prototype. In the November 1971 issue of MODEL BUILDER, we printed a picture of BJ the First and promised to publish a construction article on it, someday.
So, in spite of numerous requests, we bring it to you now, our own all-time favorite design. Certain new modifications have been added without losing the basic simplicity of the prototype. Rudder area is increased, ailerons have been widened and shortened, and the original top-opening hatch has been replaced by the bottom wing opening. For reasons discussed in the building instructions, we also made a change in the stab and fin construction. After reading that portion, you can decide for yourself whether to follow it... "
Direct submission to Outerzone.
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User commentsThank you for all these plans. I made the the Big John from these. The Big John has been made smaller to 1,4m and is electrified. Great flyer. Here are some pictures [more pics 005, 006]. Thank you again for all your good work!
RalfMuskens_Netherlands - 29/03/2018
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