UFO (oz6024)

About this Plan

UFO. Pattern plane by Joe Bridi. 65-1/4in span, 692 sq in area, for .61 engines and 5 channel RC. Model # pl-698. Designed by Joe Bridi. Featured in RCM 9-77.

Quote: "It has been interesting to watch the evolution of pattern R/C aircraft over recent years. The changes we can all recall by flipping through the pages of some old RCM magazines were brought about for more than appearance reasons alone. Though looks do undoubtedly play a part, there are several other more significant factors which have stimulated the on-going modifications we've seen. For example, probably one of the most easily remembered was the emergence of reliable proportional RC equipment. As a result, the airplanes no longer needed as much built-in stability so the maneuvers could be flown more accurately. And, proportional control of the surfaces made flying much smoother and more predictable. New, more powerful engines made it possible for the planes to fly faster. Then retracts made it possible to build cleaner pattern aircraft and designs were modified to take advantage of this new development. Effective fuel pumps increased the power of our engines and the airplanes flew at still greater speeds.

While pattern pilots have become more and more adept at making their planes respond in unbelievable ways, they have also continued to experiment with the design of their airplanes to take advantage of a new development or to try out a new idea about what might make this or that maneuver go better. Changes made in search of that elusive edge that hopefully will add a few points to their scores at contest time.

It's interesting to note that all of these factors seem to be kept in motion by re-occurring changes in the AMA-FAI contest pattern. New aircraft designs fly the pattern better and/or the pilots just get better at it. Changes are made in the pattern to make the contests more challenging. Then new designs are created to fly the new pattern and the pilots do the job better. Changes are made in the pattern, and on and on.

Joe Bridi's birds have evolved as have the aircraft of any of the pattern pilots who have been able to hang in there successfully over the years. First there was the Kaos (oz6251); a pattern ship which, as far as we know, has been unsurpassed in pattern contest wins since it was first flown. And it can still be found flying in Class A successfully in many pattern contests. Then, when other pattern aircraft began to sprout retracts, and change-overs made in the Class D and FAI patterns, the Kaos became less competitive. Then came the Super Kaos (oz5523); a cleaner, faster plane with retracts that flew the revised AMA-FAI pattern better. Contest wins proved the point.

More changes in the AMA-FAI pattern, coupled with the availability of pumps, created new demands on pattern aircraft. To meet these new challenges, the Dirty Birdy (oz4915) hatched to begin its history of contest wins for Joe and many other pattern fliers.

Now we present Joe's latest, the UFO. While at first glance this RC pattern aircraft seems to bear a very strong resemblance to the Dirty Birdy, several significant design changes underscore the fact that looks are only skin deep; this is really a new flying machine. Taking advantage of a pumper, retracts, and a tuned pipe, the UFO uses a swept-back wing and stabilizer for better roll characteristics. The stab is thicker to increase the drag at the back end to make the tail more stable in some of those near-stall maneuvers. Anhedral is used at the stab to keep it out of much of the wing turbulence for better control at lower speeds. The deeper fuselage makes retract installation easier. The increased side area at some critical points along the fuselage and larger fin and rudder help out in knife-edge flight. The thicker wing cross section - shades of the Kaos - makes for better constant speed flight in those big loops and diving maneuvers — and the longer fuselage offers increased stability. The UFO makes its debut to join the unending quest for perfection.

Building Notes. We're presenting the building notes for the UFO based on a couple of assumptions. First, because the aircraft is designed for the contest-minded pattern flier, we've assumed that the builder has already had experience in building and flying this kind of RC aircraft. It's a high performance model airplane designed to do a job; fly the AMA-FAI pattern. And it does that well! A second assumption we've made is that all of the wood parts are ready - that is, all of the pieces like the wing and stab ribs, bulkheads, fin, rudder pieces, elevator halves, and such, have already been cut out. Incidentally, the stick-on templates available from RCM will save you loads of time. We cut up some plans and stuck the pieces to the wood with rubber glue.

Getting back to the wood, you will probably find it hard to locate some of the sizes called out on the plans. Joe cuts his own wood and you may have to do the same, or substitute. We solved most of our problems by buying balsa pieces of the proper thickness and then ripping them to the correct width..."

Supplementary file notes

Article.
Left wing panel.

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