The Pathfinder series of stunt designs.

A history.  By John Miller

 

Many of my readers may have wondered about the Pathfinders, how they came to be, and what are the different versions that have existed.

 

It might surprise some to hear just how many different versions there really are. For instance, they have been built for just about any size engine you can imagine, starting at 1/2A and up to .60 size. They have included, not only profiles, but full bodied versions. Most have retained the signature, combat inspired airfoil, though a few used something more conventional.

 

The beginning.

 

Back when the first one was built, They didn't look anything like they do now. The numbers were about the same, but the fuselages looked more conventional, and most were set up as tail draggers. The fuselages were used with salvaged wings and tail planes. It seemed a shame to not use perfectly good parts after a crash. Many modelers have been doing this for years. At first, they were given names that described the linage of the salvaged parts combined with "Chicken" to describe the plane. There were numerous Noble Chickens, Thunder Chickens, Sky Chickens, (Skylark wing) and such.  Eventually, in the late 60's, the design started taking on more of it's current form. They featured a Jet look, with many using trike gear. Gordan realized that there were easy pattern points available for a design that could do smooth takeoffs and landings. Trike gear excels in ground handling, so, eventually Tricycle became the preferred gear.

 

A few of these early "Chicken" designs were still around at the beginning of the '90's, One, a Noble Chicken, may still exist, but alas, most have gone on to the big hangar in the sky.

 

It was about 1993 when Pete Peterson was getting back into the Hobby-Sport of competitive Cl aerobatics. Pete, as a young lad, had flown with Gordan, Jim Rhoades and others from the Utah State Aeromodelors club. Pete was looking for a good profile to re-learn, and practice the pattern with. He discussed his desires with Gordy, and what he was looking for. Gordy suggested he couple the wing from his Challenger Combat ships, with the latest “Chicken” fuselage, and that was the beginning of the modern Pathfinder.

 

Yep, it’s a marriage between a Combat design, and a profile stunter fuselage for recycled parts.

 

Gordan, over the years had been building, and winning combat, with his own design. The Challenger started life as many did, a modified Flight Streak. Over the span of a few years, it lost almost all resemblances to it's parentage. Gordan found that he could build them faster and straighter, if he made the airfoil flat from the high point to the trailing edge. He could use a flat building surface and no jigging was needed. This was pretty good thing to have, when you were building a bunch of them at the same time.

 

He found that larger, thicker; wings didn't give up as much speed as was thought by most at the time. He seemed to have an added benefit of not losing speed as badly as other, thinner winged, designs did when maneuvering. He'd show up with a combat ship that had a wing as thick as a Nobler, and 48” or better span. Often, his opponent might be a little faster when flying level, but when they started maneuvering, he'd eat them alive, 'cause his plane kept it's speed up.

 

Another secret he learned with the Challenger design was that his modified airfoil seemed to allow him to carry the CG further back, while maintaining stability. He reduced his control throws, which also lessened his drag when maneuvering. All in all, a pretty successful combat design, Good enough that a foam winged version won the first Bladder Grabber.

 

He built a series of Challengers, each pushing the envelope by being thicker than the previous version. He had found, and proven in actual combat, that the drag from these thicker sections wasn’t near the problem some thought it was, especially considering the advantages.

 

Gordan loaned Pete the “Chicken” fuselage drawing and a rib from one of his really thick winged Challengers. Pete went home to build what would become, after consultations as to other numbers, the first Pathfinder. When He brought the finished, but unflown plane to club meeting, the remark was made that it would never fly well with that combat airfoil. The plane proved the skeptics wrong on its first flight, flying better than many of the built ups that were being flown in the club at the time.

 

Another was built, and I asked to have the fuselage drawing, and the airfoil to make the first complete Pathfinder drawing.  It needed to be done, so more Pathfinders could be easily built in the future. I was at the time studying for a degree in Cad at the local College, and it made a good project for one of my classes. Several more were built locally, and then we published the design in Flying Models, back in 1994. Smith model products kitted the first design, published as the Pathfinder Pro. It had a large wing, 58" long, and used a semi I beam type construction, but otherwise not too different than later versions.

 

The next year brought a slew of variations. The first 1/2A Pathfinder was built by Dale Smith. It differed from most 1/2A designs for its time, it was quite a bit larger than most previously seen. It flew very well with a Cox Tee Dee .049. It was decided that a drawing would be created using Dale’s numbers..

 

At the same time, I desired a full-bodied version for my own stunt work. I had built and flown the profile, and liked it. I started with the Profile drawing and made modifications to convert it. It kept the same faux I-beam look, but the fuse was stretched a bit to allow a longer root chord. It lost its Hershey bar rectangular plan form, and gained a tapered, swept leading edge.  Gordan checked out the changes, made some suggestions, and I started building the plane. It served me well, getting me through the cut in Advanced at my first Nat’s, in 1995.

 

Also a smaller, .15-.35 sized version was built and flown by Dale Smith, but, since it gave about the same performance, it was easier to build the bigger one to a decent weight, so as far as I know, that was the only one built. After a nasty crash, I was, given  the wing. It’s hanging on my shop wall today.

 

Development continued at a rapid pace. Gordys .60 sized full body was built after the ’95 Nat’s. It used the same faux I-beam wing, and that would later, be the cause of its demise.

Gordy had a good season on the plane. It flew well with good corners. One day after flying the pattern, he decided to see how small and tight he could do a bunch of squares. They got pretty tight and small before the outboard wing blew up. Hmmm, maybe we should look at changing the spar type. My 40 sized version had developed a bit of wing bowing in hard corners. It probably had a cracked spar from several bad landings. I hung it on the wall, and there it is today.

 

By ’98, I was now doing drawings for Brodak. I talked to him about this neat profile stunter I knew about. As things went, John was interested, but Gordan wanted to make some changes he felt were needed. The Pathfinder Mark 2 was born. The faux I-beam was gone, so were the half ribs, replaced with standard ¼” sq. spars and leading edge sheeting. The span was reduced, but most everything else remained the same.

By ’98, I was now doing drawings for  I talked to him about this neat profile stunter I knew about. As things went, John was interested, anted to make some changes he felt were needed. The Pathfinder Mark 2 was born. The faux I-beam was gone, so were the half ribs, replaced with standard ¼” sq. spars and leading edge sheeting. The span was reduced, but most everything else remained the same.

Carl Shoup, over in Colorado, had built a pair of them, a full sized and a 1/2A version. He finished them identically, they were a trip to see fly. Later when Carl built another one, he added a bit more to the top of the vertical stab. This worked out well, and the Brodak kit was changed to reflect this improvement.

 

 

were a trip to see fly. Later when Carl built a

 Right after the plans were drawn for the Mark 2, I drew up the plans for the Mark 3 profile. Basically a profile that uses a tapered wing layout similar to the full bodied versions. Several have been built over the years.Tim Meeks also built several versions  of the MK3 as full blown I-beamers.

 

 During the summer of 2007, we finished up a pair of Pathfinder twins. They are powered with a pair of .15’s. The plane is roughly the same size as the well-known .40 sized Mark 2. The tail moment is 1 inch shorter, the vertical stab is changed slightly, and the main fuselage is a built up profile to save weight..The Twin was published in “Flying models” during the summer of 2010.

Gordan really enjoys flying his, and is often heard saying that the little twin is his best flying plane.

 

 During the spring of 2008, we began building what Gordan says is the Last Pathfinder. It’s a full bodied design for a piped, or rear exhaust, engine. It uses a NACA 6 digit airfoil, rather than the more familiar combat airfoil. Known as the Pathfinder L.E. (for last edition), it was published in “Flying Models” during the summer of 2009.

 

 Gordan has said that this will be the last Pathfinder, but then there’s that full bodied twin we’ve talked about, oh yeah, the 1/2A twin, and a .15 sized Pathfinder LE.

 

Here is a picture of both mine, and Gordy’s Pathfinder LE’s

 

So, there you have it, a short history of the pathfinder design. It’s hoped you enjoy yours as much as Gordan, I, and others, have ours.