SKY PUP NEWS






Newsletter No. 29                                                                                                                                                          June 1993


Todd Douma Returns to Oshkosh ‘92

Bob Schaeffer Setting More Sky Pup Records

Sky Pup Builder Update

Construction Tips

New Pup Completed in the Northwest

The Terry Rockwell Story

Letter from Newton Borden

Landing Gear Damage Repair

Al May's Card


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SKY PUP NEWS is published irregularly, once or twice a year, for builders and owners of the Sport Flight Sky Pup ultralight. Unless specifically stated, all ideas, suggestions, and building tips are strictly the opinion of the contributor and have not been approved by Sport Flight Engineering. No warranty is made as to the airworthiness of modifications or building tips. The subscription rate is $1.50 per issue. Back issues are $1.00 each. A full set of back issues is $25.00. Write to Dan Grunloh, P.O. Box 368, Loda, IL 60948. Please call me at 217-386-2213 after 9 PM if you have any questions about the Sky Pup or the newsletter. Also send photos and details about your project so others can share your experiences.


Todd Douma Returns to Oshkosh ‘92





























Todd Douma of Hortonville, WI flew his Sky Pup to the Oshkosh ’92 convention. This was his second year at Oshkosh and Todd is still the only builder to actually FLY his Pup TO the convention. Also, all four Pups which have been at Oshkosh have been there at least twice. Todd’s Pup was essentially the same as it appeared the previous year, except the wheels had been changed to wheelbarrow tires with nice aluminum covers. He had a landing accident on the return trip from Oshkosh ’91. He flew to his Dad’s farm and was dismayed to find that no hay fields had been cut. He chose to land on a road he had used before. While trying to avoid poles on one side, he hit tall weeds on the other and the Pup turned sideways, broke both wheels, and went into the ditch. Damage to the fuselage was very minimal. One final note; the Oshkosh ’92 Convention video tape produced by EAA includes a brief shot of Todd coming in for a landing (you have to look to find it).


Bob Schaeffer Setting More Sky Pup Records


Bob Schaeffer of Boise, ID called in March ’92 to report he has accumulated 430 hours of flying time (see issue no. 26,28) and will exceed the time needed to build the Pup this year, his goal since completion. When I saw Bob in August at Oshkosh ’92 he was up to 498.5 hours. Also, he decided to try and see how many airstrips in his area he could land at in only one day. He searched for airstrips and carefully planned the route. The final total was 51 airstrips in one day. Some were only touch and go’s, but it took almost 5 hours flying time. At Oshkosh ’92, he showed us a map with all the airstrips marked and the route that was used. A truly amazing record. Bob report some engine wear after almost 500 hours of flying. He has worn out the carburetor. Carb slide and guide pin slot were worn. Float guide pins worn thin and the sleeves in floats were almost gone. He replaced the guide pins with brass hardware rod and the sleeves with new brass tube which were an exact snug fit. Last minute news July 1, 1993: Total flying time is now 608 hour and everything is OK. Bob decided to best his previous record for the “Worlds Smallest Sky Pup” (see issue no. 23). The new version fits on a one dollar bill and won an award at a local model contest. I will include a better photo in the next issue.


























Sky Pup Builder Update


-----Iowa Pup Almost Ready to Fly-----

Dana Rauch writes Dec. ’92 that he has the entire airframe covered and is now working on the controls and engine installation. Dana plans to visit another Pup builder, Ray Dean from Melvin, IA, who will weld up his exhaust system and help with the mounting. If things go as planned, he hopes to have his sky Pup at Oshkosh ’93 for our 10th Anniversary. He still has to build a trailer. Dana called June 1, 1993 to say his Pup is 99% completed and still hopes to have it at Oshkosh but will probably not be flying at the convention. When he visited Ray Dean he learned that Ray has damaged his Pup in a forced landing. Apparently, a ground adjustable prop had been installed with the wrong pitch. The engine reportedly ran OK on the ground but quit soon after takeoff wit only 20 ft of altitude. The forced landing in a field completely totaled the front of the fuselage (wecan’t stress enough the importance of ensuring that your engine turns the correct max RPM at full throttle BEFORE you take off (6200-6400 RPM for the Rotax 277)). If the Rotax turns less than 6000 RPM or more than 6600 RPM at full throttle you should correct the problem before attempting flight.


-----New Illinois Builder-----

Don Handley or Martinsville, IL reported he has the right wing ready for cover, left wing hasD-cell, aft ribs and trailing edge. The tail feathers are built. Says he has been on the project over two years and doesn’t intend to try to rush to completion. He is taking his time, enjoying the building process, along with the frustration of not having four hands! He says the centersection is coming along but he would like to see a fuselage to clear up some questions in his alleged mind.


-----Most Northerly Sky Pup-----

George Gaudet of Iles De La Madeleine, Quebec wrote in April ’92 that with only 4 month construction he has completed the wings and tail and has put 300 hours in the project (see issue no. 28). He says he hopes everyone doesn’t get the impression that the weather up there is always like the colored description given by his friend, Paul Pontois. The winds there are terribly stormy or near calm. There’s no in between. That’s why he would like to hear from readers any idea about building a shelter over a wing deployed Sky Pup. See the mailing list for his address.


-----Pup Project with Musical Overtones-----

New builder Harris Hanser of Warren, OH called to say he has purchased a partially completed Sky Pup from a builder in Kansas. He says the workmanship was very good as the original builder was a violin maker! The Pup was about 2/3 completed (the D-cell was ready for plywood), and he has a new Rotax 277 still in the box.


-----News of Other Projects-----

At Oshkosh ’92, a builder from Quebec reported that Paul Pontois (issue 13,18) has begun work o a Hi-Max. It will be interesting to hear how it compares with his Sky Pup. Also, I have a note that Al Clements of Sechelt, B.C. (issue no. 17,18,21,23) has started building a second Pup to replace the “Green Machine” which was destroyed in a weather related accident.


-----Sky Pup Plans Needed in Brazil-----

Sky Pup News received a plea from Luis Fortado of Rio Claro, Brazil asking for help locating a set of plans for the Sky Pup. There is growing interest in homebuilt aircraft in Brazil. If you can help start a new litter of Pups in South America, please write to….

International Designers Club Engineer Luis R. Fortes Fortad AV. 2 #1718 –Rio Claro, S ZC 1350 Brazil, South America


Construction Tips


-----Bonding and Cutting Wing Spar Foam-----

Arthur Hall of Garner, NC wrote in July ’92 about a method for bonding and cutting 2 inch sheets of foam together to get the 4 inch thickness required for the main spar. Most builders can find the 2 inch or less sheets of foam locally, but the main spar often requires a special order and shipping costs. Splicing foam components is permitted anywhere in the airframe though it will add weight. The hotwire however will not cut through the bond line. Arthur has found that a carbide tipped blade on his bench saw will cut through the foam and epoxy bond line. He cuts just outside the line and then uses a sanding block with 80 grit to smooth the surface. He also reports that epoxy will hold rib caps on 100% but Titebond glue can be pulled off. Sport Flight Engineering announced in an early newsletter that epoxy is recommended for all the different bond types, wood to wood, wood to foam, foam to foam.


-----Idea for Sealing and Protecting Foam-----

Paul Koleamainen of Lake Osweggo, MI called with a question about sealing and protecting foam parts on the Pup. The plans call for polyurethane on fuselage foam (under the fabric) to protect from fuel. Latex paint has been suggested for interior foam in the wing and tail to reduce ultraviolet degradation. Paul says why not use oil based enamel throughout the airframe instead. He tested latex paint versus enamel and found much better protection against solvents. He plans to cover his Pup with conventional aircraft fabric and methods so the foam must be protected from the fabric cement. He will use a fast dry oil based enamel primer on the entire airframe instead of latex on the foam and polyurethane on the wood. 4-26-92


-----Full Size Rib Templates Available-----

Builder Guenther Schmidt of Seattle, was sent several sets of rib templates. He carefully plotted out the airfoil and then duplicated it with an oversize copy machine. Write to me or to him if you would like to use them. He says he can make more copies (these are new plots, not copies of the templates that were once available from Sport Flight). Guenther reported he came to be the guest of builder Harry Grape at a local EAA meeting. The club president reported he saw Bob Schaefer and his Pup at the Alvard Desert and was quite impressed.


New Pup Completed in the Northwest

















Included here are a couple photos from Bob Schaefer of Boise, ID. This white Pup with tri stripes belongs to Dave Scott and Larry Reidenaur and was built with advice and help from Bob. No details are available but the engine appears to be a Rotax. The photo on right shows the ne Pup with Bob’s (now) 600 hour bird.


SKY PUP NEWS SUPPLEMENT TO ISSUE NO. 29


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THE TERRY ROCKWELL STORY





























On the occasion of the 10th anniversary of the Sky Pup design, Terry Rockwell, of Susquehanna, PA, one of the early builders (see issue no. 4, 12) sent the following letter summarizing his experiences with his Sky Pup. Terry was a model airplane enthusiast (U-control and RC) and had the help of his father who flew Cubs in his younger days. He saw the ad for the Sky Pup in Ultralight Flying magazine and sent off for the info package and later the plans. Here's his story in his own words.


We began actual building in October 1983 and completed it in May 1984.

Several times during the project I called Steve Wood and he was always very pleasant and helpful.

My Dad dropped out of the project about 2/3 of the way through when he realized I was actually serious about flying the little bird. The guys down at McKinney’s' field paid me periodic visits during the building of the Pup and I think they had a few doubts about any positive flight ever happening, but not me! I knew, just knew it would be OK. The ultralights of choice those days as you know were mostly rag and tube and most people looked at the Pup with amusement and commented, you're not really going to fly that thing are you?". To which I'd reply ''oh yes, I don't see why it shouldn't fly just great, I built it all myself and completely trust the design and my workmanship''. Usually at this point they'd shake their heads and ask my wife Wanda how much life insurance she had on me. She never seemed overly concerned so I guess the coverage was adequate.


The great moment finally arrived when we transported the Pup to McKinney's Field via my brother Poppy's Chevy Pickup. We got a few startled looks as we passed through town on our way to the strip. Naturally it started to sprinkle and I felt a little uneasy as the Pup wasn't covered. We got it unloaded and bolted on the wings as I was anxious to do some taxiing up and down the grass strip. On the third trip down the runway, the left axle tube slid off the maple gear beam and down she went, breaking my nice new prop. I was devastated. Reluctantly we took the wings off and put the Pup in the hangar alongside Tom's Kolb Flyer and Mel's Skyseekers.


While waiting for the new prop, I did an engineering change to the gear so the axle tubes could never again slide off no matter how great the side forces. I felt confident about flying the Pup for a variety of reasons. I knew my model airplane experience had taught me a lot and I knew my building techniques were good. I was also working at Link Aviation and spent line hours ''flying'' simulators ranging from F-4's to the F-l4's, and even the F-117A. Lastly, Mel had been given a little dual in a Cessna 150 flying around the area using rudder only for turns in preparation for the first Pup flight.


Finally, the new prop came in and I was back taxiing up and down the strip. holding forward pressure on the stick and keeping the tail up as the Pup tracked straight as an arrow. Sometimes it seemed like the reduction belt was slipping and I'd stop and tighten it and it would be OK again. I was getting used to the rudder bar and the cockpit felt natural after a while. I learned to grab a wheel for a tighter turns. The time had finally arrived when I felt it was now or never. Wanda was cooking hamburgers and had prepared a picnic real for the gang assembled. We all gathered around enjoying the fellowship of ultralight flyers, family and friends. I keep in thinking about the PLAN. The PLAN was to go full throttle, lift off, climb to 50 ft. or so, throttle back and land. The weather was perfect-., a warm June evening, no wind, just right. I taxied down, turned around, and executed the first part of the plan.


The Pup climbed quicker than I anticipated, and for the first time in my life I was flying alone at least 50 ft in the air. I didn't panic, but decided to skip the part about throttling back and landing. I was going to go for it! My wife and friends were astonished to say the least. I felt OK as the Pup cruised along past the end of the runway and out over the Susquehanna River. Something didn't seem right though-., I was no longer climbing and seemed to be losing airspeed. The Cuyuna was maxed out but I wasn't getting full thrust.... The belt drive was slipping badly. No time to lose my wits now. I had read Stick and Rudder several times and everything about stalls and glide technique was running through my mind like a freight train. I remember Mel pointing out power lines passing across the river just ahead. I breathed a sigh of relief as I spotted them ahead and above me.

I lowered the nose and set up a glide, looking down at the river below through the hole in the floor. With tall trees on my left and a steep bank on my right, I was committed to a water landing. By this time I'm not getting any thrust so I pull the power back. The river took a bend to the left up ahead and we had no rain recently. I could see the bottom on the left side. There were willow-type bushes, flat rocks and gravel on the bottom and the water was about a foot deep. The Pup touched down and was rolling along quite well with those large diameter wheels and I thought ''so far, so good".


The next thing I knew we were on our nose and I got a bath! A mini tidal wave washed over the engine and me as the Pup stopped and went up on its nose and then back down. I quickly got out and surveyed the situation. We had landed on the only shallow spot around. The prop was scuffed but not damaged and there was no apparent damage to my beloved Sky Pup. I heard a noise and looked up to see Mel and Mike circling in the Cessna 150, flaps down and waving madly I waved back standing in the water next to the Pup.


Mel landed back at the field and assured everyone that everything was fine. My brother Stan located an aluminum rowboat and was working his way upstream while everyone else was trying to bust through the thick riverbank vegetation in an effort to reach the landing site. When they got there they broke out in laughter as they saw me standing there soaking wet next to the beleaguered Sky Pup. We gently lifted the Pup onto the boat, setting it onto cushions, and proceeded to float it back down the river. The whole thing looked like something out of Indiana Jones'' as the Pup came down the river on the rowboat.


We did sort out the problem with the reprove belt and my first successful solo flight on June 30, 1984. I lifted off, flew down the valley, did a 180, came back and landed. As I taxied back to the hangar I killed my engine. My daughter after ran up to me and I took her in my arms, savoring the moment as Mel and Eddie began ripping my shirt tail off. It's a feeling I'll never forget as long as I live.


On July 28, 1984 Ron Jones and Tom Wood from Norwich, NY (see issue No.l6) trailered down their Sky Pup and flew with us. As far as I know , that was the first time two Pups had ever flown together. Tom also flew along with his twin-engine Kolb Flyer. The Sky Pup was my faithful companion for the next two summers as we flew around most of Susquehanna County and even getting into New York at times. In early 1986, I began construction of a Kolb Firestar and as it neared completion around August, began to get a funny queasy feeling in my stomach realizing that my Sky Pup days were numbered. I had a buyer for it and the Firestar was waiting to be flown. I wondered how I would handle a plane with ailerons for the first time.


On September 25, 1986, I flew the Pup for the last time. It was a cloudy grey day of about 65 degrees with hardly any wind. The dark grey skies matched my feelings as I motored around the area, the little Cuyuna humming along. I felt as if I was losing a member of the family, my best friend. As I taxied up to the hangar for the last time, I slowly reached up and shut off the engine and just sat there not wanting to get out.... thinking shout the last three summers and all the wonderful and sometimes scary times we'd been through together. I finally climbed out telling myself that all things must come to an end even when we don't like them to. Driving home my eyes watered over as reality set in and I thought about the little plane sitting in the hangar and what the future held for it. As I parked the car in the driveway and entered the workshop, I gazed at the finished Firestar and began to feel a little better. A whole new adventure lay ahead that's for sure I thought.

But I knew I'd never forget where it all began.... seeing an ad for a little ultralight from Sport Flight called the Sky Pup.



Letter from Newton Borden


Newton Borden of S. Weymouth, MA sent an update back in December of 1991 that didn't make it into issue no. 28 so here it is 1 1/2 years later.































I still have my Pup but didn't get much time on this summer due to lousy weather. I did take advantage of the good days and maybe got 25 hours. After many one-wheel crosswind landings the gear spring broke through the bottom of the fuselage. This was due to landing on my right wheel most of the time and the free floating spring bar acting as a leverage finally broke through, no other damage was done and I still managed to taxi back with it.


I wood screwed an aluminum angle bracket to the gear spring on the inside of the fuselage on each side and then went through the hard spot that supports the gear with a 1/4 x 28 and through the aluminum angle ( see drawing). This supports the spring bar on each side and prevents that lever action.


I towed my Pup down to the ''flight Farm'' in Monterey, N.Y. again this year. Again I had the only sky Pup but met and talked with many other builders. My Pup always gets lots of attention and I spend a good part of the time answering questions. I had a bad experience on my first takeoff at Monterey. At about 300ft. with no runway left, I developed a bad vibration and loss of 3/4 of my normal RPM. I managed to hold what altitude I had and tried to get into downwind position for a landing, but with 10-15 other planes in the pattern and no way to communicate, it took me three tries. On the last attempt the engine quit and I cut off a couple of planes, hoping they saw my dead prop and got it back down on the runway with no damage. I found my adjustable pitch prop was to blame. One of the blades had loosened up and went into high pitch. The announcer and spectators, not knowing the trouble I was having, thought I was making the low passes for their benefit.


Did you happen to see the picture of my Pup and article in Kitplanes magazine? I am still receiving mail and getting calls from all over, even a builder in Malaysia. I have received over 50 letters and calls and have managed to answer all of them. It's cost me plenty in photos, copies and postage but I met a lot of nice people so it's been all worthwhile.


I have a Mitchell U-2 SuperWing in my shop that was built by a friend who is hesitant to fly it. He has gotten of the ground and flown the length of the runway, but that's as far as he goes. He has a Zenoah engine in it but it was always overheating or the reduction belt was slipping etc. I suggested he let me put my Konig engine in it and we both fly it. He bought the idea so I'm in the process right now. I had a buyer for my Pup less engine and instruments but I haven't heard from him in a while. I would rather keep it but have no place to store it and don't want to leave it outside. It's still in good shape and is now painted in the mid 30's Air Force colors, orange wings and stabilizer with the early stars, blue fuselage and fin with vertical red, white and blue stripes on the rudder. A dummy gatling gun sticks out the nose like the A-l0 Warthogs. It gets much attention at the shows. I got invited to show the my Pup at Otis AFB at their annual show but had to pass as I already had plans to attend the Maunder event. I sure would have liked to get a video of it parked alongside the F-l5's and Thunderbirds. Maybe next year. As you know, there's never a dull moment owning and flying a Sky Pup.




- - - from Al Mays, in a card to announce the birth of his son, Lucas.



























Dan J. Grunloh

P.O. Box 368

Loda, IL 60948


Original Newsletters edited by Dan Grunloh, electronic edition compiled by Edwin Lelieveld and Roger Ford.


SKY PUP NEWS








Newsletter No. 27                                                                                                                                                   January 1991



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SKY PUP NEWS is a quarterly newsletter for builders of the Sport Flight “Sky Pup”. The purpose of the newsletter is to provide for the open exchange of information and to encourage builders t share their experiences of building and flying the Sky Pup. Beginning with this issue, the newsletter will be written by Sky Pup builders and enthusiasts. Unless specifically stated, al ideas, suggestions and building tips are strictly the opinion of the contributor and have not bee approved by Sport Flight Engineering Inc. No warranty is made as to the airworthiness o suitability of modifications or building tips. When in doubt, you should follow the plans as close as possible and contact Sport Flight Engineering if you have questions. SKY PUP NEWS is compiled and distributed by Dan Grunloh…Rt 2, Box 82, Potomac, Illinois, 61865. Subscription are $7.00 for the calendar year ($10.00 overseas). If you want to talk about the Sky Pup, or about airplanes and homebuilding in general, please feel free to call me at (217) 569-2121 late evenings.

Please keep sending your letters and photos.


Ray Dean’s Fast Track to Fame















Sky Pup builder Ray Dean of Melvin, IA bought a partially completed kit from a friend, began work in May 1990, and made his first flight in August. He sent photos to Kitplanes Magazine and the Pup was featured in the February 1991 issue. Since the magazine came out, he has been flooded with letters asking for information and also received a call from the magazine for more information as they have also received many inquiries. A future issue of Kitplanes will have details about the newsletter so there will probably be many new builders as a result. See elsewhere in this issue for Ray Dean’s letter about his Pup.


Caution Mounting Chute on Landing Gear


Howard Fortner of Houston, TX called to say that he had a forced landing due to a fuel flow problem (strictly pilot error). He intentionally ran his upper fuel tank dry to determine the maximum time before switching to his other fuel tank. However, the engine would not restart. He later learned this was not due to lack of fuel but rather he forgot to reduce the throttle before attempting the restart. The bad news was that he encountered a ditch during the forced landing and broke off the landing gear which pulled on the cable activating the chute mounted on the gear. The ballistic chute fired off resulting in a very costly repack. Darnn! Anyone contemplating mounting a ballistic chute on the landing gear had best re-think the routing of the activating cable. Howard will switch to a soft pack ballistic but says he has had poor response and service from BRS.


Cooling the Rotax 277F

















A number of Sky Pup builders have reported high CHT temperatures with the free-air Rotax 277 engine. The problem has also occurred in the Mini-Max ultralight which has the same engine configuration. Readings of 375 to 425 degrees are common. The primary cause is assumed to b the gear drive and prop hub which block air flow to the cylinder when mounted in the up position. Also, the cooling fins on the head are curved the wrong way. Several builders have tried to rotate the head and cylinder 180 degrees but this leads to numerous complications. Included here are photos and drawings of two cowlings (or air scoops) which have proved helpful on Sky Pups. Before you add a cowling, you should determine that your gauges are reliable and the prop i correctly matched to your engine. Though a 60x28 prop is suggested, differences in props and engines make this only a rough guide. If the max RPM is over 6300 to 6400, the engine will not be operating under enough load and it will run hot! The engines do vary a lot! My original factory prop turned 6600 to 6700 RPM. After trying two more props the RPM was down to 6400 with a 60x31 prop. However it still ran about 400 degrees CHT when climbing. After trying several different cowling designs it now rarely exceeds 350 degrees. Also you will find out how difficult it is to get accurate numbers for RPM and temperature. Most analog gauges are greatly affected by vibration in the instrument panel. I carried instruments in my lap and strapped to my arm to totally eliminate vibration induced errors. Ideally, you should make repeated tests in climb and cruise with severa different probes on the engine to detect any hot spots and make corrections for ambient temperature. This procedure should be repeated for each variation in cowling design. Unfortunately the Rotax factory has never done this work and few of us have the time, equipment, or knowledge. In spite of the lack of truly scientific testing, the two cowling designs shown her have demonstrated a 50 to 75 and even 100 degree drop in CHT temperatures on several Sky Pups. The photo on the left is from Howard Fortner, who also built and extra cowling which h sent to me for testing. I got a 75 degree drop in climb and about 50 degree drop in cruise. the photo on the right is from Paul Pontois. See also Bob Schaeffer’s Pup in its trailer, and other Pup in previous issues. Generally, the cowling should enclose the sides and top and it should extend 2 to 3 inches in front of the cylinder to be effective. Note Howard Fortner’s cowling flares outward to collect more air. These are actually “air scoops” not true pressure cowlings so accepted rule about inlet and outlet size may not apply. They can be built out of any thin sheet metal, plain, galvanized, or aluminum and painted if desired. The lower edges must be secured against vibration with bolts, tabs, springs, or safety wire. Cracks will eventually occur at sharp bends or welds if vibration persists. One final idea. It has been suggested that a prop spinner might also help the cooling by improving the airflow over the engine. You must preflight prop spinners often as they are prone to come off in flight and could damage the prop or airframe.

(Fortner cowling)











































Note: The above sketch needs to be joined with the following sketch (2piece)













































Note: The above sketch needs to be joined at the center with the sketch below.(Triangle)










































(Join tabs)














































More Ideas for Trailers


A trailer setup for transporting your Pup is most essential. You may have to haul the Pup fro your workshop to the airport for its first flight, travel to distant airshows, or more important, rescue the bird after a forced landing on a cross-country flight. The design of your trailer is important as it is easier to damage the Pup when trailering it than when flying. An open trailer may be better than a fully enclosed design as you can see in the rear view mirror how it’s riding and if your ropes have come loose. I’ve had friends haul their ultralight to Oshkosh and not discover until they arrived that it had come loose and been damaged in its trailer. Also, fully enclosed box trailers are sometimes top heavy and more sensitive to wind. Ideas for trailers have been reported previously in issues no. 14, 21, 22, and 24. The photo on the left is from Ray Dean of Melvin, Iowa. The wings are mounted in a box, covered with a tarp, and the fuselage is loaded tail first on top.



















The photo on the right is from Bob Schaeffer of Boise, Idaho. The wings are mounted in foam cradles above the fuselage. The design is similar to that used by Newton Borden and Donald Diggs (issues 21 & 24). The logical points for attaching the wings to the trailer is at the steel win attach brackets as they are the strongest part of the wing. Use aluminum bolts or rods if you wan to reduce wear on the fittings over rough roads. The fuselage will be more stable if you also bungee it down from the centersection wing attach fittings. I threaded two strands of no. 12 insulated copper wire through the holes to make a loop for the bungee. You will also want to tie the control stick or attach wind locks to the elevators to prevent them from flopping up and down on bumpy roads.



Working On the Belly






























Working on the belly is easy if you know this trick. I had flown my Pup for four years before I discovered that the Pup would sit in this position. Turn the prop horizontal, drain or remove the fuel tank, and push down on the nose until the CG comes ahead of the gear. It’s quite stable in this position though I wouldn’t try it in a wind. Put a foam pad under the nose if you want. Great for cleaning underneath, or inspection and repair of the tail.


Miscellaneous


Terry Chupp of Elkhart, IN is an avid RC builder and new Sky Pup builder who is building a 12x16 ft. shed for construction of a Pup. Will it fit?


New builder Jon Speak of Burlington, IA is planning on writing a multi-part magazine article on the construction of a Sky Pup.


Builder W. Laan from New Zealand reported that a 36 inch wingspan RC model Sky Pup was flow at the National Championship competition in New Zealand.


For Sale: 50 yards brand new Ceconite fabric for Sky Pup. Paid $257, make offer. Contact Dan Rauch 3187 Country Park Dr., Toddville, IA 52341


Thomas Wood of Unadilla, NY, (issue #16) reports that he still has his Sky Pup but it’s under repair. His partner, Ron Jones, was teaching his 16 year old stepson to fly when he dropped it in and broke the gear. The nose and engine came off at the wing support. It’s currently back up on its gear and waiting for warm weather for recover and paint.


Greg Pardee of Owosso, MI (issue #18) has sold hid Pup to David Meihl of Springboro, PA. Greg has built and is flying a Mini-Max which he says is very responsive and fast but draggier than the Pup.


Ray Dean called to say he has straightened out the plastic wheels on his Pup which were bent in landing accident by putting them in the oven at 350 degrees for 10 minutes!!


RAY DEAN'S LETTER


I purchased this airplane from a friend who had started on it a couple of years ago and had made very little progress. I began working on it in May 1990, and flew it for the first time in August, 1990. It is powered by a Cuyuna 215 engine and covered with Stits aircraft fabric, which I put on, and my wife, Barb, shrunk to fit (she only made one small hole with the heat gun). It is painted with Sears Weatherbeaten paint. I built the reduction drive myself and used a 52'' propeller. I made the instrument panel from aluminum and installed an airspeed indicator and exhaust gas and cylinder head temperature gauges. I found the 2 gal. gas tank in a friend's junk pile.


Although the windshield is optional, I made one from 1/16 lexan and am glad I put it on as it sure helps keep the wind out of my face. I did not put anything over the hole in the bottom. The air that comes through there is minimal. I used a tail wheel rather than a skid. Originally, the tailwheel was not steerable, but I latter added the necessary cables to make it steerable. I made the gap seals from denim fabric, using eyelets and matching shoelaces for fasteners and they work very well. Barb made the seat cushions from denim.


On August 7, 1990 a couple of friends, my wife and kids helped load the plane in pickups to haul it to the airport where the wings and gap seals were installed. After admiring our handiwork, I taxied up and down the runway for a while to get the feel of it. Slowly at first then faster, letting the tail come up, and eventually it was time to bring the whole airplane off the ground. I ''hopped'' a few feet off the ground several times and when it looked like the Pup was going to be airworthy, I went ahead and took off. The plane handled okay, but there was a problem with the reduction drive, it was nose heavy, had pretty strong vibration, and also needed a lot of right rudder. After a couple of short flights in the traffic pattern, I hangared it until I could get some of these problems worked out. I did, however, put it on display at our airport breakfast and it sure drew a lot of comments and head shakes (people could not believe anyone would actually fly something made out of styrofoam.


The reduction drive went back to the drawing board, a new belt, and two weeks later it worked like a charm. I added some weight to the tail (a little at a time) and a small aluminum trim tab, raised the front of the engine a bit, and changed the brackets on the exhaust pipe to reduce vibration. After making these modifications, the engine purrs like a kitten and the aircraft handles very well. Once all the ''bugs'' were worked out, another friend who owns an automobile striping business, added the finishing touches.


In mid September, I decided to fly the Sky Pup from the airport to my home about 7 miles away so I could keep it in my own hangar and eliminate the drive to the airport every time I wanted to fly it. I planned to land in my front yard but wasn't sure there was enough room. After making a pass and deciding that it looked okay, I went for the landing. I had to come over some trees about an eighth of a mile from my yard. Everything went fine and the landing was a ''greaser''. However, after the nice touchdown I realized I did not have enough room to get stopped (what brakes?). It was too late to add power and get off the ground again, and another set off trees were meeting me head on. When all was said and done, the airplane had pitched forward, breaking the prop and bending the spokes on the tires. I learned that even though 350 feet may be enough to take off, it is not enough for landing. I now have a new prop on 'order and will put on different tires. My wife says it sure would be nice to have some brakes (I wonder why?). I plan to have as Sky Pup back in the air before the snow flies. – Ray Dean





















































































More Ideas for Trailers
























A trailer setup for transporting your Pup is most essential. You may have to haul the Pup fro your workshop to the airport for its first flight, travel to distant airshows, or more important, rescue the bird after a forced landing on a cross-country flight. The design of your trailer is important as it is easier to damage the Pup when trailering it than when flying. An open trailer may be better than a fully enclosed design as you can see in the rear view mirror how it’s riding and if your ropes have come loose. I’ve had friends haul their ultralight to Oshkosh and not discover until they arrived that it had come loose and been damaged in its trailer. Also, fully enclosed box trailers are sometimes top heavy and more sensitive to wind. Ideas for trailers have been reported previously in issues no. 14, 21, 22, and 24. The photo on the left is from Ray Dean of Melvin, Iowa. The wings are mounted in a box, covered with a tarp, and the fuselage is loaded tail first on top.

The photo on the right is from Bob Schaeffer of Boise, Idaho. The wings are mounted in foam cradles above the fuselage. The design is similar to that used by Newton Borden and Donald Diggs (issues 21 & 24). The logical points for attaching the wings to the trailer is at the steel win attach brackets as they are the strongest part of the wing. Use aluminum bolts or rods if you wan to reduce wear on the fittings over rough roads. The fuselage will be more stable if you also bungee it down from the centersection wing attach fittings. I threaded two strands of no. 12 insulated copper wire through the holes to make a loop for the bungee. You will also want to tie the control stick or attach wind locks to the elevators to prevent them from flopping up and down on bumpy roads.


Working on the Belly






























Working on the belly is easy if you know this trick. I had flown my Pup for four years before I discovered that the Pup would sit in this position. Turn the prop horizontal, drain or remove the fuel tank, and push down on the nose until the CG comes ahead of the gear. It’s quite stable in this position though I wouldn’t try it in a wind. Put a foam pad under the nose if you want. Great for cleaning underneath, or inspection and repair of the tail.


Miscellaneous


Terry Chupp of Elkhart, IN is an avid RC builder and new Sky Pup builder who is building a 12x16 ft. shed for construction of a Pup. Will it fit?


New builder Jon Speak of Burlington, IA is planning on writing a multi-part magazine article on the construction of a Sky Pup.


Builder W. Laan from New Zealand reported that a 36 inch wingspan RC model Sky Pup was flow at the National Championship competition in New Zealand.


For Sale: 50 yards brand new Ceconite fabric for Sky Pup. Paid $257, make offer. Contact Dan Rauch 3187 Country Park Dr., Toddville, IA 52341


Thomas Wood of Unadilla, NY, (issue #16) reports that he still has his Sky Pup but it’s under repair. His partner, Ron Jones, was teaching his 16 year old stepson to fly when he dropped it in and broke the gear. The nose and engine came off at the wing support. It’s currently back up on its gear and waiting for warm weather for recover and paint.

Greg Pardee of Owosso, MI (issue #18) has sold hid Pup to David Meihl of Springboro, PA. Greg has built and is flying a Mini-Max which he says is very responsive and fast but draggier than the Pup.


Ray Dean called to say he has straightened out the plastic wheels on his Pup which were bent in landing accident by putting them in the oven at 350 degrees for 10 minutes!!


RAY DEAN'S LETTER


I purchased this airplane from a friend who had started on it a couple of years ago and had made very little progress. I began working on it in May 1990, and flew it for the first time in August, 1990. It is powered by a Cuyuna 215 engine and covered with Stits aircraft fabric, which I put on, and my wife, Barb, shrunk to fit (she only made one small hole with the heat gun). It is painted with Sears Weatherbeaten paint. I built the reduction drive myself and used a 52'' propeller. I made the instrument panel from aluminum and installed an airspeed indicator and exhaust gas and cylinder head temperature gauges. I found the 2 gal. gas tank in a friend's junk pile.


Although the windshield is optional, I made one from 1|16 lexan and am glad I put it on as it sure helps keep the wind out of my face. I did not put anything over the hole in the bottom. The air that comes through there is minimal. I used a tail wheel rather than a skid. Originally, the tailwheel was not steerable, but I latter added the necessary cables to make it steerable. I made the gap seals from denim fabric, using eyelets and matching shoelaces for fasteners and they work very well. Barb made the seat cushions from denim.


On August 7, 1990 a couple of friends, my wife and kids helped load the plane in pickups to haul it to the airport where the wings and gap seals were installed. After admiring our handiwork, I taxied up and down the runway for a while to get the feel of it. Slowly at first then faster, letting the tail come up, and eventually it was time to bring the whole airplane off the ground. I ''hopped'' a few feet off the ground several times and when it looked like the Pup was going to be airworthy, I went ahead and took off. The plane handled okay, but there was a problem with the reduction drive, it was nose heavy, had pretty strong vibration, and also needed a lot of right rudder. After a couple of short flights in the traffic pattern, I hangared it until I could get some of these problems worked out. I did, however, put it on display at our airport breakfast and it sure drew a lot of comments and head shakes (people could not believe anyone would actually fly something made out of styrofoam.


The reduction drive went back to the drawing board, a new belt, and two weeks later it worked like a charm. I added some weight to the tail (a little at a time) and a small aluminum trim tab, raised the front of the engine a bit, and changed the brackets on the exhaust pipe to reduce vibration. After making these modifications, the engine purrs like a kitten and the aircraft handles very well. Once all the ''bugs'' were worked out, another friend who owns an automobile striping business, added the finishing touches.


In mid September, I decided to fly the Sky Pup from the airport to my home about 7 miles away so I could keep it in my own hangar and eliminate the drive to the airport every time I wanted to fly it. I planned to land in my front yard but wasn't sure there was enough room. After making a pass and deciding that it looked okay, I went for the landing. I had to come over some trees about an eighth of a mile from my yard. Everything went fine and the landing was a ''greaser''. However, after the nice touchdown I realized I did not have enough room to get stopped (what brakes?). It was too late to add power and get off the ground again, and another set off trees were meeting me head on. When all was said and done, the airplane had pitched forward, breaking the prop and bending the spokes on the tires. I learned that even though 350 feet may be enough to take off, it is not enough for landing. I now have a new prop on 'order and will put on different tires. My wife says it sure would be nice to have some brakes (I wonder why?). I plan to have as Sky Pup back in the air before the snow flies. – Ray Dean



Original Newsletters edited by Dan Grunloh, electronic edition compiled by Edwin Lelieveld and Roger Ford.


SKY PUP NEWS






Newsletter No. 28                                                                                                                                                         January 1992



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SKY PUP NEWS is published irregularly, once or twice a year, for builders and owners of the Sport Flight Sky Pup ultralight. Unless specifically stated, all ideas, suggestions, and building tips are strictly the opinion of the contributor and have not been approved by Sport Flight Engineering. No warranty is made as to the airworthiness of modifications or building tips. The subscription raet is $1.50 per issue. Back issues are $1.00 each. A full set of back issues is $25.00. Write to Dan Grunloh, P.O. Box 368, Loda, IL 60948. Please call me at 217-386-2213 after 9 PM if you have an questions about the Sky Pup or the newsletter. Also send photos and details about your project so others can share your experiences.


Todd Douma at Oshkosh ‘91


















Sky Pup enthusiasts at Oshkosh ’91, who were there on the first opening day, were delighted and surprised to see a Sky Pup appear in the ultralight pattern. It was Todd Douma of Hortonville, WI with SN 1916 (first reported in issue no. 22). He had flown for just the one day. Todd’s Pup was only the 3rd plans-built Sky Pup to fly at Oshkosh. Seeing this very high quality Pup first hand was a real treat. Todd works for a company in the aircraft business and has access to materials an methods not as easily available to many of us. For example, the custom leather headrest and use of real swaged cables instead of nicopress sleeves. The attention to detail and quality of workmanship can be seen throughout the aircraft. He machined his own adapter plate to mount a Rotax gearbox on the Kawasaki 340, the custom made throttle features a nicely knurled handle, and the lightweight muffler is stainless steel. Changing exhaust systems on 2-strokes can be tricky and Todd admits he has a minor flat spot in the midrange which is not a problem. the weight savings helps offset the gain from the use of a slightly heavier engine. The final empty weight is within the range of Rotax powered Pups at 229 lbs but the engine is much smoother (an much cheaper). The blue and silver covering was achieved with light aircraft fabric and finishes, and should last a long time. Thanks again Todd for showing us how to build a really good one!


Sky Pup Builder Has Flown 286 Hours His First Year


Bob Schaeffer of Boise, Idaho (see issue #26) writes that on the one year anniversary of the first flight of his Pup, he has logged a total of 268 hrs. Total time as of December 1991 is 340 hours. He says it could have been more, but due to screw ups and subsequent repairs the Pup was out of commission for two of the first twelve months. It hasn’t been idle for very many weekends. Also these hours were logged with only a 2.5 gal fuel tank and flights were seldom over one hour. Bob sent along some aerial photos. The Snake River from 6000 ft over Murphy, ID and the mountain and valleys are beautiful. No wonder he flies so often. The only parts wearing out were the tailwheel and the elevator horns on the control stick wore the holes out of round. He noticed the turnbuckle clevis is wide enough to allow the bolt to move sideways and wear on the hole. The replacement horns are doubled so there is less movement. (Builders please note: thin washer should be added between the ears of the turnbuckle clevis to reduce lateral movement.) Bob say he broke off two landing gears during rough landings so he laminated a piece of 16 Ga. Steel to the bottom of the maple gear with epoxy. He says it seems quite strong but doesn’t have much spring to it. Bob also designed and built custom disc brakes for his Pup. See enclosed photos and drawings. He says the total weight of the brakes, cables, and two levers mounted just below the bend of the control stick is 2.5 lbs. They are not strong brakes but do help in slowing and turning. Any stronger brakes may nose over the plane or twist the wood axle. Be advised that dimension on the enclosed drawings are approximate and that parts should be cut to fit. Also, the cable attach bracket in the drawing is different (and better) than the one in the photos. Bob also added an electric trim tab to the elevator which he says works great. It’s powered by 3 AA batteries, controlled by a switch (spring loaded center off) and the motor is from a RC-model servo. Retractable landing gear servos work best.


Another Wisconsin Pup Ready to Fly































Rex Rhode of Montello, Wisc. Reports his Sky Pup shown at right is completed and ready to fly. The covering is white sheath lining, the colors are grey and white and the finish is latex and polyurethane. The engine is a Rotax 277 with a homebuilt 4-belt reduction (2.33 to 1). The 54x32 prop did not initially deliver the full RPM that was expected. Reducing the outlet diameter of the homemade exhaust system brought the RPM up to 6000. Tires are wheelbarrow 8”x4” rims hence the need for a reduced prop diameter. The empty weight is 220 lbs and the fuselage is 2” wide than the plans. The CG came out to 5.9 inches and he says the tail lifts easily. Initially the use Rotax refused to start until it was discovered the cam that drives the points was loose on the crankshaft. Rex reported he was having so much fun with taxi testing he made 10 long runs each direction until he overheated and froze up a wheel due to lack of lubrication. He has since added wheel bearings. The Pup also features a lexan windshield hinged in front and held down with bungee, and a lexan cover over the hole in the floor. An unusual modification is the control stick which is mounted off to the right side so it doesn’t get in the way when climbing in and out. Re has a trailer which is an old 16 ft camper gutted out. The wings slide in close to the ceiling, and the fuselage rolls underneath. He covers the back with a tarp and it’s ready to go. The trailer can still be used for camping.


Jim Liebich Ready to Fly


Jim Liebich of Hoffman Estated, IL reports his Zenoah powered Sky Pup is finally ready to fly. Se issue #21. The trailer he had built was collapsed by snow the previous winter (the trailer was empty at the time). He has now replaced the tarp over conduit framework with plywood sides and foil coated Styrofoam roof. Now the Pup can be stored in the trailer and his garage is a garage again instead of a hangar. Jim just recently retired and now hopes to find the time to get the bird in the air. He has a problem finding a place to fly as he lives only about 10 miles from O’Hare International airport.


Update from Al May


Al Mays of Normal, IL (see issue #15) reports his Cuyuna powered Sky Pup is still flying nicely and that he has logged about 170 hours. The only problem has been a forced landing and a broken landing gear. After about a one hour flight, he returned to his home strip and the engine quit in the landing pattern when he throttled back to idle. After turning on final, he could see he would not clear the fence at the end of the runway and elected to turn and land in a neighbor’s field. There was no damage. After pushing the plane 150 yards to the airstrip, the engine started on the first pull. He suspects carburetor ice. The broken landing gear occurred when he hit a small bump while taxiing and was due to defective materials. The wood kit from Wicks was excellent except for the landing gear which was laminated lengthwise from two pieces. It worked without problem for about 100 hours and many landings. When the gear broke and split in the middle it was found to have a knot on one of the inner faces. The break had spread from that point outward in both directions. After making repairs, the Pup was happily back in the air with a solid maple gear. Also Al reports the performance of his Pup increased dramatically when he switched to an adjustable prop. The original 58x24 prop gave only about 5000 RPM at full throttle.


Beware of “Velocity Never Exceed”


I received a report from a Sky Pup owner that he has repeatedly flown well in excess of VNE (69mph) on numerous occasions without any problem. I strongly urged him to show some restraint. VNE is a little different than maneuvering speed or stall speed. So many different things can go wrong at high speeds. Designers look at all the different factors and then pick a “best estimate” based on the mission of the aircraft. It is then flown to that speed to see what happens. If everything is OK, that’s the VNE. You can fly at VNE all day if you don’t exceed the structural loads in gusts or in a sharp maneuver. Just because one copy of a homebuilt design has exceeded the design VNE does not mean they all will. Besides, next time his control cables might be a little looser or the dive a little longer and a flutter begins. The real danger at the higher speeds is not VNE but maneuvering speed or structural cruising speed. A sudden control movement or a wind shear can easily over-stress the wings when you are at VNE. If you exceed 69mph in a Sky Pup at any time, or fly over 54mph in rough turbulence, you are asking for trouble!


Trouble Finding Fabric Cement?


Several builders have reported difficulty location latex contact cement for gluing on the fabric cover. Kingko which was available from Wicks can no longer be obtained. I cannot find Borden’s acrylic latex cement which I used on mine. Dana Rauch has found that DAP acrylic latex contact cement can be obtained or ordered from the hardware store. He says it works great. It’s slightly thicker than the others and dries faster. He uses a hair dryer to set the glue even faster. Another source might be Macklenburg-Duncan acrylic based contact cement which I have not yet tried. Any contact cement labeled “flammable”, contains solvents which will dissolve foam. To us them any foam must be very well sealed with polyurethane to protect it.


Don Caron’s Warning About Unknown Foam


Don Caron of Santa Fe, TX purchased a completed Sky Pup (SN 2536) from another builder and has discovered that the blue foam that was used was not like the Dow or Corning extruded polystyrene which is recommended. It was a rough, brittle medium cell foam which crumble easily. The original source of the foam could not be determined. He sent a sample to Sport Flight where it was tested and found to have a shear strength of 20 psi. The Sky Pup design calls for strength of 70 psi minimum. Further examination of the airframe revealed that part of the aircraft including the main wing spar was built with the correct foam. Don will be facing a major rebuild before the airframe can be flown. The aircraft had a KFM engine, good workmanship, and good instrumentation though it was heavy at 250 lbs dry. It had added float hard points, spoilers, tailwheel, brakes, rudder pedals, inside cables, and about 25 sq. ft. of added 1/16 plywood in the aft fuselage. It had been taxied but not flown. Don also had suspected there was water accumulation in the rear fuselage and found that a quick thrust of the knife would easily separate the plywood from the fir. It is imperative that drain holes be provided in the aft fuselage bays an anywhere water might accumulate (cut a notch in the bottom of each fuselage bulkhead and drill hole in the tailskid mounting block, or provide a hole for each fuselage chamber). Anyone considering purchase of a completed Sky Pup should ask about the type of wood, foam, and glue that was used. Be suspicious of any aircraft with extensive design modifications. Consider building it yourself!


GREETINGS AND MISCELLANEOUS FOR ISSUE NO. 28


Dear Sky Pup Friends,


Sorry this newsletter is going out so late again. It should be called SKY PUP HISTORY instead of SKY PUP NEWS. My eternal gratitude goes out to all of you for your patience and support for this newsletter. The last time I sent out the newsletter, it was so late I had to send two issues together. This time I've Just combined everything together into one. I regret to announce the reason for the added delay is that I had an on-the-lob accident in January which resulted in 22 stitches in my hand and a cast on my right arm from the elbow to the fingertips for a month. I fell in the lab where I work at the University of Illinois and stuck a piece of glass into my hand. Tendons and nerves had to be reconnected. I quickly discovered all the things you cannot do with only one hand. The cast has been off for three weeks and I'm starting to use my right hand again. I can now hold a pencil, tie my own shoelaces, drive a car, and type with two fingers instead of one. I still can't feel two of my fingers. It will be 6 months or so before I can expect to regain the full range of motion and complete feeling in my fingers.


CONGRATULATIONS go to Howard ''Mud Puppy'' Fortner, of Houston TX who received recognition in the December 1991 issue of ULTRALIGHT FLYING magazine for his participation in the Texas TXC-IOOO. This is an organized 1000 mile cross country flight which spans several southwestern states. Howard showed that the humble Sky Pup can indeed go on a long cross-country just like the latest $10,000 machines.


BING CARBURETOR UPDATE: Rotax has announced a change in the design of the Bing carb floats which formerly had an aluminum guide tube. Material from a very worn guide tube could block the fuel jets or cause the floats to stick. (See issue #17 for a report of my own experience with this problem.) The new carburetor floats have a brass guide tubes for better sliding ability and less wear. Check your floats for wear and contact your Rotax parts source for the new floats.


REPORT FROM THE FAR NORTH: Paul Pontois sent news about George Gaudet, who is the most northeastern builder in North America. He lives in the La Madeleine Islands, very small islands in the Atlantic Ocean, belonging to Quebec. The last time George called for a building tip there was a snowstorm, with 6 feet of snow around his house, wind blowing 90 MPH, and the sea was frozen out for 7 miles. George, a professional photographer, started his Pup about 6 months ago.


NEW BUILDER Bob Miller of Nashville, TN is Just getting started on his Pup, but sent along pictures of his previous project, a Woodhopper on floats. The photos show a very nice yellow wire-braced bird on floats and in the air over a scenic lake. This is a very rare ultralight, and a major accomplishment.


ED TONER the airplane model builder first mentioned in issue no. 23, sent a copy of the magazine article which featured his free-flight Cox .020 powered Sky Pup. It was in the March 1991 ''FLYING models". Looks like it would be lots of fun. (Here's some trivia: Ed Toner's model uses a flat bottom airfoil which has a greater pitching moment. Note enlarged horizontal stabilizer in enclosed drawings.


OSHKOSH '92 CONVENTION: This year is the 40th anniversary of the event and will likely result in an unusually large turnout. I hope someone will bring a Sky Pup. The ultralight pattern and runway have been very much improved. Here is a chance for many thousands of people to see their first Sky Pup. I will be there and may have my Pup if I can get it and my trailer refurbished in time. See you there!


Dan Grunloh


Bob's Brakes

























































Electric Trim Tab








































































Ed Toner's Sky Pup Model








































More Photos for Issue No. 28

Kenneth Thompson's 1/8 scale model and middle right.

















Earl Gray's Pup for sale      



















Bob Schaefer's tail fin                                                      Paul Pontois morning flight                      












   







Dan Grunloh

P.O. Box 368

Loda, IL 60948



SKY PUP NEWS




Newsletter No. 26                                                                                                                                               October 1990

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SKY PUP NEWS is a quarterly newsletter for builders of the Sport Flight “Sky Pup”. The purpose of the newsletter is to provide for the open exchange of information and to encourage builders t share their experiences of building and flying the Sky Pup. Beginning with this issue, the newsletter will be written by Sky Pup builders and enthusiasts. Unless specifically stated, al ideas, suggestions and building tips are strictly the opinion of the contributor and have not bee approved by Sport Flight Engineering Inc. No warranty is made as to the airworthiness o suitability of modifications or building tips. When in doubt, you should follow the plans as close as possible and contact Sport Flight Engineering if you have questions. SKY PUP NEWS i compiled and distributed by Dan Grunloh, Rt 2, Box 82, Potomac, Illinois, 61865. Subscription are $7.00 for the calendar year ($10.00 overseas). If you want to talk about the Sky Pup, or about airplanes and homebuilding in general, please feel free to call me at (217) 569-2121 late evenings. Please keep sending your letters and photos.

First Pup Reported from Idaho














Bob Schaefer of Boise, Idaho called in September to say his Rotax powered Sky Pup was almost ready to fly. He bought a used engine for $600 and built his own exhaust. The 60x28 prop is fro Tennessee Propellers. Bob covered his Pup with fabric from T.E.A.M. and the finish is acrylic late enamel. This is a very sharp looking Pup. The colors are blue and yellow. The airframe is “per plans” except for a Steerable Tailwheel and a 6 inch access hole behind the seatback. Empty weight is 210 lbs. Yes, the Sky Pup can be built light! Bob painted all exposed foam with latex. H tested small pieces exposed to sunlight and discovered that even one brush coat will stop the otherwise rapid deterioration of bare foam. His plastic wheels are the type with metal star insert at each end of the hub and are reportedly stronger than Troxel wheels. Brass bushings were made on a lathe. A shroud was added to help cool the engine and he is experimenting with a cardboard lip on the rear (exit side) which seems to help even more (see cowl flaps on old radial engin planes). Bob also built a very nice trailer for his Pup. Prior to flying his Pup, he took instruction i a 2-seat Drifter. The first flight of the Idaho Pup was made on September 16th by his instructor. I flew hands off with a max RPM of 6200 and minimum cruise at 4200 RPM. It will easily out climb Mini-Max with the same engine (it helps to build light). Unfortunately, the landing gear broke while taxiing after a number of takeoffs and landings were made. The maple axle had wavy grain and the break occurred at a weak spot. A replacement was fabricated with vertical laminations. Bob say he took off on a 45 mile XC flight not long after his first flight. The nearby Alvard Desert is 11 mile long and 6 miles wide, smooth and hard, no rocks or plants. It even has hot springs for taking bath on flying outings!

Sky Pup Crunched in Wind Gust
















On the morning of August 16, 1990, the unnamed Sky Pup builder and pilot was returning from a 45 minute flight in overcast but calm conditions when he ran into a rain shower. He put the Pup in a right turn but suddenly the Pup was in a steep bank to the left and descending. He added power but only had about 60 feet of altitude and didn’t have time to recover. The Pup crashed through a line of trees and sheared off both wings near the attachment points. It hit the ground and bounced about 15 feet into a 4 foot deep ditch and came to a very sudden stop. The pilot was amazed that he was unhurt. However, the airframe was totaled.











The aft fuselage and rudder were the only undamaged components. The prop was splintered a foot on each side of the hub but 3 or 4 tree branches an inch thick had been chopped off. The landing gear was ripped off on the initial impact and the forward fuselage and centersection cracked loose when the Pup hit the ditch. The engine mount and other major structural points were intact. There was no evidence of control system failure. The pilot practically shoveled the “Pup droppings” back into its trailer for a ride to the city dump. Bolts, fittings, and hardware which could be reused were saved. The pilot believes he must have flown into a wind gust or shear associated with the rain squall. Surface winds were cal moments after the accident. He had logged 207 hours total on the Pup. His flight suit saved hi from abrasions and his helmet was scarred by an overhead fuel valve. He states that the airframe is unbelievably tough and that it saved him from serious injury. He is wondering what color to make his next Pup and resolves to build it lighter than his first attempt. The empty weight started out at about 230 lbs but ended up near 250 lbs with the addition of more paint, a full cowling and other additions. If there is a lesson to be learned from this accident it is clearly that you should avoid flying in questionable weather conditions. Though conditions were calm at the time of this accident, a large system can produce rain, wind gusts, and lightning very unexpectedly. Unseen thunderstorms hiding above the overcast can produce a “gust front” and wind shear 30 mile away. Flying under heavy overcast is always tricky as the ceiling can drop unexpectedly. You may be forced to fly too low for safety in case of a wind gust or engine failure. Be a “fair weather” pilot.

Ray Dean's Letter

I purchased this airplane from a friend who had started on it a couple of years ago and had made very little progress. I began working on it in May 1990, and flew it for the first time in August. 1990. It is powered by a Cuyuna 215 engine and covered with Stits aircraft fabric, which I put on, and my wife, Barb, shrunk to fit (she only made one small hole with the heat gun). It is painted with Sears Weatherbeater paint. I built the reduction drive myself and used a 52'' propeller. I made the instrument panel from aluminum and installed an airspeed indicator and exhaust gas and cylinder head temperature gauges. I found the 2 gal. gas tank in a friend's junk pile.

Although the windshield is optional, I made one from 1/16 Lexan and am glad I put it on as it sure helps keep the wind out of my face. I did not put anything over the hole in the bottom. The air that comes through there is minimal. I used a tail wheel rather than a skid. Originally, the tailwheel was not steerable, but I latter added the necessary cables to make it steerable. I made the gap seals from denim fabric, using eyelets and matching shoelaces for fasteners and they work very well. Barb made the seat cushions from denim.

On august 7, 1990 a couple of friends, my wife and kids helped load the plane in pickups to haul it to the airport where the wings and gap seals were installed.

After admiring our handiwork, I taxied up and down the runway for a while to get the feel of it, slowly at first then faster, letting the tail come up, and eventually it was time to bring the whole airplane off the ground. I ''hopped'' a few feet off the ground several times and when it looked like the Pup was going to be airworthy, I went ahead and took off. The plane handled okay, but there was a problem with the reduction drive, it was noseheavy, had pretty strong vibration, and also needed a lot of right rudder. After a couple of short flights in the traffic pattern, I hangared it until I could get some of these problems worked out. I did, however, put it on display at our airport breakfast and it sure drew a lot of comments and head shakes (people could not believe anyone would actually fly something made out of styrofoam.

The reduction drive went back to the drawing board, a new belt, and two weeds later it worked like a charm. I added some weight to the tail (a little at a time) and a small aluminum trim tab, raised the front of the engine a bit, and changed the brackets on the exhaust pipe to reduce vibration. After making these modifications, the engine purrs like a kitten and the aircraft handles very well. Once all the ''bugs'' were worked out, another friend who owns an automobile striping business, added the finishing touches.

In mid September, I decided to fly the Sky Pup from the airport to my home

Mounting a Steerable Tailwheel

The addition of a Tailwheel is the most popular modification to the Sky Pup design. The original skid has the advantage of being simple, trouble free, and almost indestructible. It provides excellent service on grass runways where you have plenty of room to taxi. The skid also provide some braking action with full up elevator when landing on grass.











If you must operate from pave runways and taxi among other aircraft, a steerable tailwheel and brakes are essential. For best results the tailwheel and the swivel should both have ball bearings rather than bushings. There should be some provision for spring suspension to prevent damage during hard landings. And most important, make provisions so that side loads on the tailwheel are not transferred to the rudder horn or hinge fabric. The best method for connecting the rudder control to the tailwheel was first reported by Andre St. Pierre in issue #21 and is shown in the photo on the left. the hardware store caster is mounted on a bent bracket to provide suspension (first seen on Gerry Coppock’s Pup) and is connected to the underside of the rudder with a long spring. A tailwheel steering arm was fabricated from threaded rod with a small hole on each end for attachment of stiff wire bracket. A small wood block is added to the underside of the rudder. This method seems preferable to earlier designs which connected the steering arm directly to the rudder cabl or rudder horn. On the right is a photo of a Mini-Max tailwheel mounted on Paul Pontois’ Pup. Here the original skid block is retained so this would be ideal as a retrofit for Pups already flying with a skid. Be sure the mounting bracket has enough spring to provide some suspension. the Mini-Max tailwheel is a very well built unit. Both builders report their tailwheels work great.

Wax Your Puppy!!

After several years of storing my plane in a partially open hangar, and dealing with the dirt, bugs, and bird droppings, I finally decided to apply a thin coating of Lemon Pledge furniture polish. What a tremendous difference! Dirt and bugs do not collect on the airframe as bad and it’s much easier to clean. I suppose I hesitated to add a wax at first because of the added weight and the potential difficulty with fabric repairs. However, you have to clean the fabric with mineral spirits o alcohol to remove any oil before making repairs anyway, and the weight buildup is very, very small. It really does help a lot. You should wax your prop too! The bugs that accumulate during dawn and dusk flights will wipe off much easier. A clean airplane and a clean prop will definitely give better performance.

Update from Andre St. Pierre


















Andre writes that since Kitplanes magazine published the picture of his Sky Pup in the September 1990 issue, he has received 27 letters from readers asking for information. He answered each of them and sent technical information, copies of magazine articles, and information about the Sky Pup newsletter. A large majority of those who wrote for information have decided to build a Pup and have subscribed to the newsletter. Andre also sent this photo showing modifications to his Pup which includes side windows, landing gear fairing, and a door for the opening in the floor. H gained 8-10 mph and now has a best cruise of 60 mph. The landing gear fairing was built using the same foam used for seat padding, assembled with contact cement, and secured on the landing gear with duct tape. The door in the floor was built with ¾ inch foam, opens inward, and uses fabric hinge. When closed, the door is secured by a small Velcro tape. It works great. André reports that he has flown his Pup 106 hours in 1990. He attended a local EAA chapter fly-in, and the Sky Pup made such an impression, he was asked to give a lecture on the aircraft. Late several people said it was the most interesting they had seen in several years. It really surprised a lot of his fellow builders.


Dan Grunloh

P.O. Box 368

Loda, IL 60948