R/C Chief (oz7476)

About this Plan

R/C Chief. Radio control version of the Veco Chief. An R/C version of Bob Palmer's 1950s controline stunter. Span 53in, area 560 sq in, weight 70 oz, for .30 -.40 engines.

Quote: "An R/C version of the C/L Chief. A new twist to the Old Timer theme, an R/C version of the famous C/L stunter, originally designed by Bob Palmer. R/C Chief, by Ron Farkas.

For several years I had been thinking of building a radio control version of one of the control-line planes that I learned to fly on. I missed the era of the ignition engines and the evolution of control-line airplane design. Some of my friends who were modelers back then have in the past told me very interesting stories that often got me in the mood to start building something new. So one day, while I was visiting my good friend, Hank Stumpf, I spied a Veco Warrior (oz7584) hanging up on the wall and my brain started working. This was my first stunt airplane with a built-up fuselage, but somehow it sure looked bigger when I was a kid. Hank suggested that the Chief (oz10269) would make a better R/C conversion because it was considerably larger. When Hank produced a dusty box containing a complete Chief kit, I couldn't possibly put the project off any longer. This particular kit was produced by Dumas who had taken over the original Veco line. The kit is no longer in production but you might still see one buried in the back of a hobby shop. That's quite a record for a design that goes back to around 1950.

I just had to know more about the Chief so I contacted the original designer, Bob Palmer. The story goes something like this. Up to around 1949 the usual stunt airplane was small and fast with a big ignition .60 for power. Bob's Chief was larger than average and he initially intended to use an Orwick .60 engine. Hi Johnson did the drafting work and Bob did the building and flying. Around this time Bob was teaching a buddy to fly
with a Go-devil (oz960) so they put an Ohlsen .23 in it to slow it down. To everyone's amazement the plane flew a better stunt pattern at this speed, so the inspiration was born. Also around this time Bob severely injured his hand, requiring a special mitt to enable him to fly U-control at all. Flying with a .60 was too much strain on Bob's injured hand so, based upon his experiences with the Go-devil, he decided that the Chief should use a .19 to .35 size engine.

At the 1949 Nats Bob demonstrated the Chief with both McCoy .19 and .29 engines. Eventually he settled on the Fox .35 as the ideal engine for this size plane. Bob showed that the lower powered plane could generally turn tighter than the .60 powered ones and so the Chief set an example that soon became universally followed in competition aerobatics. Considering this trend and the increasing availability of glow engines, the ignition .60 soon disappeared from the market. Glow engines produced more power for their size and did not require the payload of battery, coil, etc.

Another trend-setting innovation on the Chief was the use of full span flaps coupled with the elevator. They really tightened up the turns. The use of flaps became a standard feature that still survives today. You really must have flaps to be competitive in Stunt. When the Chief was kitted it was the first production design to have flaps. Bob had many contest wins with the Chief which was followed by his famous Smoothie (oz480) and Thunderbird (oz6238) designs. So it appears that the world of competition control-line aerobatics owes a great deal to Bob Palmer and his Chief.

Bob is still active in the hobby and flies R/C with a special transmitter arrangement. His specialty is making patterns, molds and fiberglass fuselages with a lot of his work going to kit manufacturers. It was a pleasure to correspond with Bob as he is a truly dedicated modeler.

I never intended to build that old Chief kit as it will be a collector's item some day. However I used it to get the original dimensions while I completely redesigned the structure. Several problems confronted me right away like moments, balance, construction and equipment layout. The Chief is very short-coupled for an R/C airplane yet any major change would defeat the purpose of the conversion. I decided to make subtle changes in the direction of a more conventional design. I placed the wing an inch forward of its original location and the stabilizer a half inch rearward. The flight control surfaces were very large so I moved the elevator hinge line back by a half inch and trimmed down the chord of the flaps (which are now ailerons). I widened the fuselage to account for the radio equipment, fuel tank and a modern .40 size engine. The depth of the wing is so great in proportion to the fuselage that I chose to mount it permanently and provide radio access through a removeable top hatch. Otherwise the fuselage would have been rather weak through the midsection and the radio installation would be very tight. Two spruce spars and two fiberglass shafts pass through the fuselage and tie everything together very securely. The lack of a removeable wing is only a minor aggravation in transporting the model. Just about all other modifications in-volve building practices, in which case I looked for stronger, more modern or just plain easier methods.

The power, moments and generous control surfaces give the R/C Chief a spunky personality. It does not need a .40 engine, in fact a .30 would do nicely. The very thick wing section makes the R/C Chief gentle at low speeds. Still, it is too responsive for an absolute beginner. It would be best to have some experience on an aileron trainer before advancing to the R/C Chief. It is a great airplane for Sunday afternoon hot-dogging. I sincerely believe that I have captured the spirit of the original Chief. Anything else would have been just another sport airplane. The R/C Chief gets plenty of favorable comments and it is amazing how many modelers recognize it right away. If the Chief brings back fond memories for you, or if you just want something a little different from your last kit, then I suggest that you read on.

Construction. Having chosen to make the wing fixed, and needing all the available fuselage space for the radio, I decided to butt the wing panels up against the sides. The spruce spars enter the fuselage and are spliced together by utilizing one of the main formers. Two fiberglass arrowshafts pass completely through the fuselage, joining the wing panels. The ideal way to build a symmetrical wing is on a jig and in this case the jig rods become built-in spars. The result is a wing that is very strong in spite of having an 'empty' center section. Since this construction technique requires holes to be drilled in the fuselage I selected Sig Lite-Ply for the sides. If you substitute balsa then you absolutely must use plywood..."

Direct submission to Outerzone.

Update 24/05/2016: article pages, text & pics added, thanks to RFJ.

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