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Nicholas Wood's RANS S-10 Sakota

By Pat Panzera, EAA 555743, ppanzera@eaa.org

RANS S-10 Sakota

Nicholas Wood, EAA 831459, (nicholasmwood@gmail.com) is a sport pilot who proudly carries the moniker “The Seven Day Wonder.” The title was given to him by his instructors Bud Cushing and Andrew Kellogg after he completed a challenge to go from zero to sport pilot in seven days. He accomplished this on May 27, 2008. But long before he was given the opportunity to prove to himself that he had the wherewithal to pull this off, he bought into a fractional ownership of a RANS S-10 Sakota, an experimental amateur-built kit that is clearly sport pilot eligible.

The plane was meticulously built by Steven Day of Fresno, California, a machinist by trade and a perfectionist by nature. After a few hundred hours of flying, Steve decided to pull the Rotax 582 engine apart and rebuild it—just to be on the safe side. After the engine was completely overhauled to zero hours since major overhaul status, including a new crankshaft, pistons, and rods, the balance of the show-quality airplane sat in his hangar (in pieces) for nearly a decade. The plane was then sold to a friend of Nick’s. This friend then offered Nick a one-fifth share of the ownership in trade for Nick putting in some regular hours at his friend’s new business. The plan was to restore the plane to its former glory while making a few improvements along the way and for Nick to receive his sport pilot training in it when all was said and done.

To move the plane from its Fresno digs back to a hangar at Nick’s home airport, it needed to be trucked. Once unloaded into the hangar leased by their third partner, Nick and his two friends seriously evaluated all the systems. The years of sitting and the previous owner’s use of auto fuel had taken its toll on the neoprene fuel lines, so that was certainly the first order, to replace them all—as they were removed from their fittings, they literally crumbled. This was certainly alarming to all involved as some of the lines were not accessible without destructive measures, namely the flop tubes in both wing tanks and the header tank. There were no access points in any of the tanks—the only way to get to the fittings inside the tanks was to cut holes.

Fuel Tanks
Deteriorated fuel lines were not the worst of it. While finishing some preliminary work with the wings fitted in place, one of Nick’s partners made the proclamation, “You know, if we really wanted to go flying, we probably could get the plane airworthy by the end of the day.” The partners then took lunch and while reading e-mails, Nick’s partner read on the RANS e-mail list a warning about fiberglass fuel tanks failing from the use of automobile fuel (mogas). The writer mentioned a simple test to see if one’s tank was affected, and sure enough, right after lunch the two partners were heartbroken when it was determined that the tanks were toast.

After much lamentation and research, including considering changing them to the newer poly tanks offered by RANS, the partners decided to use the existing tanks as plugs from which molds could be made to cast new tanks, with the understanding that mogas was never to be used in the future. The poly tanks, although a great product, required cutting and patching the fabric—an unacceptable option for the trio as the paint on this plane is a “10”, save a bit of hangar rash suffered throughout the years.

RANS S-10 Sakota

Carbs and Cables
So with that plan in mind, the team moved forward with other tasks. New carbs were ordered and installed with new boots and new K&N filters. The existing carbs were in good enough shape to simply rebuild, but a replacement set was found on eBay for just a little more than the rebuild kits. Nick rebuilt the fuel pump and replaced all the cables. Since RANS also builds bicycles, all the lighter-weight cables such as those used for the throttle, choke, elevator trim, and the flap mechanism came from that industry, and a quick trip to the local bicycle shop netted a complete set of new material to work from. The aileron cables, however, are very robust (not bicycle related) and were in fine shape so they weren’t replaced.

Cooling System
The cooling system was in need of a little TLC, so Nick removed the radiator and all the hoses and gave everything a thorough cleaning and inspection. He then decided that the weight gain from installing high-quality hose clamps would be offset by the comfort of knowing that they won’t become a point of failure or create any further issues by cutting into the hoses. “Constant torque” hose clamps were sourced, purchased, and installed. In addition to using Belleville washers to maintain consistent pressure on the hose and its fitting, even as it expands and contracts, the band that comes in contact with the rubber hose does not have any of the typical slots found in worm-drive clamps that are notorious for cutting into the surface of the hose. A little overboard? Probably.

RANS S-10 Sakota

Exhaust System
The stock Rotax exhaust system was showing signs of neglect. Structurally it was sound, but cosmetically it was certainly the worst-looking part on this plane. Several hours with a few wire wheels and it looked like it could be chrome-plated. But Nick took a few rattle-cans of high-temperature ceramic exhaust paint and made everything look new again. Some new exhaust gaskets and some new fastening hardware, including new springs, and the system was as good as new.

RANS S-10 Sakota
A sharp eye will see the bicycle handlebar-end shifter lever used for pitch trim, affixed to a weldment on the curved control stick. In this photo, Nick is threading new cable from the flap handle to the spring-loaded flap system. The full-span flaperons are held up against the stops by a pair of strong springs.

While stringing the cable from the trim tab to the handlebar-end bicycle gearshift lever fitted to the control stick (another RANS piece of cross-over technology), Nick noticed that the elevator didn’t seem to have the proper travel. The RANS assembly manual called out the travel, but it appeared that the builder set his differently. A simple fix was to re-index the pushrod tube connection to the control stick by drilling a new bolt hole. A digital protractor from Harbor Freight was called upon for the measuring task, and as it sits now, it’s spot-on with the assembly manual.

Starter Button
Another mod brought about by the concern for safety was to relocate the starter button from the instrument panel—which is not within reach while properly strapped in—to the flap handle base between the pilot’s legs. Should there ever become a need to restart the engine in flight (maybe the header tank was accidentally allowed to run dry?), the pilot would not have to unstrap to hit the starter.

Since the plane was going to be used for training, and since it has conventional landing gear (tail wheel), it made sense that there should be differential brakes available for both occupants; the plane came with hydraulic brakes only for the left-seat. All the hardware for the retrofit was still available from RANS even though at the time, the Sakota was out of production. At this writing, it’s back in production. So the parts were ordered, preassembled, but have not been installed as of yet.

RANS S-10 Sakota

RANS S-10 Sakota

The S-10 was in need of all new Lexan when Steve grounded it. He kept the old stuff to be used as templates and passed them along to the new owners. Two 4-by-8 sheets of 3/32-inch smoked polycarbonate was mail-ordered, and with some skill and a lot more patience, the sheets were transformed into a new windscreen, two door windows, and two side panels.

Since the doors hinge in gull-wing fashion, the plans call for a piece of rubberized cloth to span between them on the hinge line, to complete the sealing job. With no source for this material available, Nick’s partner opted to use Plasti Dip (an air-cure, synthetic rubber coating similar to the rubber coating found on the handles of pliers and other such hand tools) to impregnate fiberglass cloth. The product is available in a liquid form or an aerosol spray can, so they opted to wet out the glass cloth with the Dip just as one would do with epoxy. That was a failure for multiple reasons, the largest being the viscosity was just too high. Not wanting to give up on the idea, they switched to the aerosol version, which in order to spray has a very thin viscosity. With the glass cloth laid perfectly flat and held in position, several heavy coats were sprayed on. When it cured, it was flipped over and coated on the other side. This was at least a year ago, and it seems to be holding up very well.

RANS S-10 Sakota
The original panel held a few instruments, all of which were out of the reach of the pilot if the shoulder harnesses were kept snug. From left to right: g-meter, altimeter, airspeed indicator (ASI), vertical speed indicator (VSI), GPS, and engine instruments—tachometer, exhaust gas temperature (EGT)/cylinder head temperature (CHT), Hobbs, and volts. And overhead is the radio.

Instrument Panel
The last thing to be modified was the instrument panel. The original builder was not really interested in anything except local flying, the occasional $100 hamburger, and some mild aerobatics, so minimal day VFR instruments, supplemented with a g-meter, GPS, and a handheld radio, were all he installed. Nick and his partners had no intention of doing aerobatics beyond the occasional wingover or roll, so the g-meter was out. The GPS that was built into the panel was outdated and the partners were interested in serious cross-country flight capability, so a “real” radio and a transponder was slated to occupy that spot—a handheld GPS would be carried when flights dictated its use. The final iteration of the panel design calls for the radios to be under the panel, not in it. However, that has happened as of this writing.

Since the original panel is structural and since the guys were not interested in trying to make a new one and align the 40 or so rivets with the existing holes in the airframe, the decision was made to laminate over the existing and cut new holes for the new instruments. Carbon fiber was the material of choice, more for appearance than anything else.

RANS S-10 Sakota
The new panel supports pretty much the same flight instruments with the addition of a few more engine gauges. From left to right: VSI, altimeter, ASI, turn and bank, tachometer, dual EGT/CHT, water temperature, water pressure, and volts. The upper row is the Hobbs and ELT reset.

To produce the sheet to be laminated to the original aluminum panel, the guys went to the local glass store and picked up a sheet of 1/4-inch plate window glass to use for laying up the composites. The glass was cleaned and waxed with automotive paste wax. A sheet of carbon was then laid on the glass and taped in place around the perimeter, assuring that the strands that make up the weave were perfectly straight and perpendicular to one another. Then West System epoxy was applied to what would become the back of the sheet, and with the proverbial rubber squeegee, the epoxy was forced through the matrix while also forcing out any trapped air. In order to feel completely confident with the process, this process was carried out for more than a half-hour. The payoff was a completely smooth and bubble-free finished surface. But knowing that one layer would not be strong enough to support the instruments, after the epoxy was set but still tacky, two layers of fiberglass cloth were added and wetted out accordingly. After all was cured, the finished product just popped right off the plate glass.

With the new piece completed, it was cut to rough shape with a small band saw. The face of the original instrument panel was then roughed up with an angle grinder to get a good “bite” into the laminating media, which was a five-minute epoxy. With the back of the carbon laminate roughed up as well, it was mated with the aluminum panel and weighted down.

Once the five-minute epoxy was cured, the carbon was further trimmed to fit with the band saw and ultimately a belt sander. The panel was already designed in a computer aided design program, and a full-scale template was printed. It was then just a matter of accurately locating the template on the panel and drilling pilot holes in all the critical locations and making the final cuts.

At this point it’s safe to state that the restoration is 75 percent complete with 75 percent to go. The fuel tank issue has yet to be fully resolved. The old tanks have been prepped and are about ready to begin the arduous task of producing female molds. I would assume that as soon as the tanks are completed and plumbed, the partners will once again be at the point where that can say, “You know, if we really wanted to go flying today, we probably could get the plane airworthy by the end of the day.”

RANS S-10 Sakota

During the restoration, even though the primary reason for owning the plane was to get his sport pilot rating in it, Nick was given a golden opportunity to travel halfway across the country to accept a “challenge” to become a sport pilot in seven days. He accepted the challenge and pulled it off. Now more than ever he’d like to see this plane back in the air, with him at the controls, and with his fiancée literally by his side.

RANS S-10 Sakota
Ever the romantic, Nick set up a photo shoot of his plane and asked his then girlfriend Retanda Chi to join him so they could get some photos of themselves together as well. Unbeknownst to “Tanda,” Nick’s true intentions were to ask her to marry him, and he wanted photos of that event. Since his plane is almost as close to his heart as Tanda, Nick wanted it in the photos, too.

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