Sky Pup News
Newsletter No. 11 April, 1986
Sky Pups Around the World
Patriotic Pup from Maine
Loyd Powered Pup from Michigan
Safety Item from Sport Flight
Inadequate Bend Radius in Centersection
Plans for Oshkosh ‘86
Building Tips
Miscellaneous
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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 to share thei 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, all ideas, suggestions and building tips are strictly the opinion of the contributor and have not been approved by Sport Flight Engineering Inc. No warranty is made as to the airworthiness or 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.
Subscriptions are $7.00 for the calendar year ($10.00 overseas). Your comments from the previous newslette have been very encouraging. I wish I could meet and talk with each and every one of you. 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. Keep sending your letters and photos. Color photos are fine if they have good contrast.
Sky Pups Around the World
The photo on the left is from Kim Ashton from Perth, West Australia. This has to be one of the neatest trim schemes seen on a Pup. The logo on the tail fin is reproduced on the back page of this newsletter. The simulated cabin window painted on the headrest side panels is a nice touch. Landing gear axle tubes pivot at the ends of the wood gear spring and are supported by rubber bungees at the inside ends. A hinged cockpi cover includes a small windshield. (Builders should note that use of low profile wheels could increase landin and take-off speeds by reducing the angle of attack in the 3-point position. Ground clearance of the propeller will also be a consideration).
The photo on the right is from Dr. Helmut Bucker from West Germany. No details are given but this Pup has wire-spoked wheels, a tailwheel and a twin cylinder engine with a belt drive. Control surface hinges appear to be a metal pivot type probably made from short sections of aluminum channel. Converting the dimensions to metric units and accommodating the use of metric hardware and materials would be an added challenge.
Patriotic Pup from Maine
Sky Pup SN2469 is red, white and blue and was built by Leroy Thomas from Belfast, Maine as a retirement project. He is 69 years young and says he has worked as an electrician, plumber, farmer, cabinet maker and deputy sheriff investigator. Construction took eight months and the total cost was $1986. First flight was September 18, 1985. The engine is a Rotax 277FA with gear drive and a 60x27 prop. Empty weight is 228 lbs. Weight and balance gave the CG at 5.2 in. No corrections were necessary. He plans to recover the aft portio of the wings because his original covering sags badly in cool or wet weather. It tightens up fine on hot dry days.
Leroy reported considerable vibration (not his exact words) but it is not known how it would compare to other Rotax powered Pups. He moved his instruments from the forward deck to a location under the centersection to avoid vibration damage. (All builders should be aware that a new prop is not always correctly balanced. My Shettler prop was way off. Also note that the breadboard holes must be chamfered enough s that the rubber stoppers are not over compressed). High cylinder head temps were a problem with his Rotax even though exhaust gas temps were near normal. He points out that the cooling fins on the head are curved the wrong way to scoop in air from a left-hand prop. If anyone else has overheating problems with the Rotax, please let us know about it. (Builders using the Rotax should follow the recommended one-hour break-in procedure religiously and avoid doing lots of continuous low speed taxi work immediately after break-in. When the break-in procedure is completed, either fly it or try to simulate normal operation).
Loyd Powered Pup from Michigan
Cecil Bosworth of Charlotte, MI. sent this photo of his Pup coming in for a landing. He says it flies very good, has good climb and no problems except for crosswind landings on a narrow runway. Ground handling was very easy for a taildragger. The colors are blue and yellow. The engine is a Loyd 386cc twin with the fan housing removed and the exhaust is a tuned straight pipe of about 24 inches. Empty weight is 229 lbs. Since his engine cost him only $150 and he made his own belt drive and propeller, the total cost of the complet aircraft was only $1000!
Construction took about 500 hours. Cecil says he is a life-long mechanic (both aircraft and automotive) and he has previously built a Heath Parasol and a Longster. He felt that some parts of the Sky Pup construction were harder than anything on his previous homebuilts. The covering on his Pup is aircraft fabric and the finish is two coats of semi gloss acrylic latex paint. (I am aware that several othe ultralights have been finished with latex house paint including the Minimax and some of the Fisher geodetic designs. The results look very good and I’m told it’s very easy to apply but I have no first-hand information about fuel resistance, flexibility, or possible weight build-up). Cecil says he learned (as have other builders) that a hard crosswind landing can damage the lower longeron under the landing gear. In a one-wheel landing, a downward load is applied to the longeron on the side still off the ground. Trying to straighten out a crabbing approach just before touchdown may raise one wing. Some reinforcement in the form of a wood doubler or extra fiberglass might be advisable. (On my own Pup, I added a short piece of softwood under the longeron a the gear location to serve as a “hard point” for blocking up the fuselage during construction or repairs).
Safety Item from Sport Flight
Steve Wood reported that they have reason to suspect that a centersection wing spar which was proof-loaded by the builder, may have failed because of inadequate bend radius in the lower spar cap. He says the specified bend radius of 72 inches was carefully calculated to allow a known amount of prestress in the wood. If the bend at the attach upright location is too sharp, then considerable stress will be applied to the wood even before flight loads are included. My own experience was that a gentle curve extending several inches of either side of the point of bending will allow for bonding of the spar cap without using excessive force. Some difficulty in bonding the lower centersection plywood to the resulting curve is to be expected. Incidently,
Steve says that they have been keeping busy consulting on various interesting projects including a 6-place canard and a very special one-of-a-kind design intended to break a world speed record for propeller drive piston engine aircraft. He says not to worry though, they haven’t forgot about the little guy (like us).
Plans for Oshkosh ‘86
Since the next newsletter will be out in late July, I’ve decided to include some details and suggestions about Oshkosh. Several Sky Pup builders have indicated they hope to bring their Pups to Oshkosh this year. For those who’ve never attended, convention registration is $9.00 per day ($50.00 for all 8 days) and includes the flight line pass for EAA members. Avoid trying to arrive or depart during peak hours on the weekend due to heavy traffic. To fly at the convention, you should have a minimum of 15 hours total and 7 hours on the aircraft. Camping with either a tent or vehicle is the most convenient way to stay overnight. Showers and grocery store are available. EAA campsites are $10.00 per day. Plan to arrive early or your camp will be long walk from the showgrounds. My favorite spot is a private campsite, Ollie’s Farm, which is just outsid the ultralight entrance. The silo marks the ultralight landing approach. Space is almost always available and the location is very convenient for the UL exhibit area. Look for my green tent and probably a Sky Pup sign in the front yard. The evening of Saturday July 2nd after the last ultralight flying period would be a good time fo a group gathering of Sky Pup builders. If you plan to attend, call me in July for last minute details at (217) 569-2131.
Building Tips
1. Gerry Coppock says be sure to provide for drainage of the upper forward wingtip compartment before you cover the wings. Because of wing dihedral, a drain hole in the fabric will not suffice. You need small hole in the tip rib or gusset.
2. Jim Beatie reported he developed a strong sensitivity to Apco Saf-t-poxy. He switched to Gougeo marine epoxy and used PR-88 hand protectant from Wicks Aircraft Supply (allergic reactions to epoxy can be very serious so you should avoid direct contact with the skin. The PR-88 cream is very highly recommended)
3. Phill Hartzell sent a sample of “Herculite” fabric which he used to make the wing gap covers. It’s strong, lighter than naugehyde and will not stretch. Attach with Velcro.
4. Several builders reported that covering the fuselage sides is simplified if the control cable fairleads ar added after the fabric has been applied.
5. Harry Grape (SN2729) installed Teflon bearings in the wheels, around the elevator torque tube and on the rudder slide block. Glue will not stick to Teflon so small screws or bolts must be used.
6. Foam brushes are ideal for applying the polyurethane varnish (especially the last coat). I also use foam brushes to apply the latex fabric cement.
7. Be sure to bend the control horns with at least a 3/32 radius. One builder said all of his broke before the first flight. It’s recommended that all bends be perpendicular to the apparent “grain” of the metal.
Miscellaneous
The next issue will have pictures and details of a Sky Pup built by A. Napper of Kingsgrove N.S.W. Australia. also received pictures from Newton Borden whose Konig powered Pup is nearing completion. This is a very sharp deluxe model. Paul Pontois (also nearing completion) sent pictures and detail drawings of his ballistic chute installation. The canister mounts above the centersection on wood and foam reinforcements which include a false aft spar component. The bridle is attached to the spar and has back-up straps going to the seat cross member area. More details later.
Several builders have asked about clamping and fixturing. An excellent short article on the subject is, “Clamps and clamping in general” by Tony Bingelis in EAA Sport Aviation magazine February 1983. It has lot of good information in a few pages
A significant number of subscribers have only recently started construction of their Pup. We can expect to see Sky Pups being hatched out for many years to come. Here are some of the builders whose Pups are nearing completion - Jim Beatie, Lake Geneva, I - Donald Diggs, Monon, I - Lanney Fields, Rimersburg, PA - Paul Pontois, Quebec Canada - Paul Rasmussen, Urbandale, IL - Newton Borden, So. Weymouth, MA - Larry Meyer, Alberta Canada - Todd Douma, Appleton, WI - Dan Grunloh, Potomac, IL
Sky Pup News
Newsletter No. 12 July, 1986
Fuji-Robin Powered Pup
Newsletter Editor’s Pup Flying
Canadian Pup Ready to Fl y
Feedback from Early Builders
Miscellaneous and Building Tips
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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 to share their experiences of building and flying the Sky Pup. Beginning with this issue, the newsletter will be written b Sky Pup builders and enthusiasts. 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 Inc. No warranty is made as to the airworthiness or 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. Subscriptions 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.
Fuji-Robin Powered Pup
This Pup was built by Alfred Napper of Kingsgrove N.S.W. Australia. The color is white with a yellow nose and fuselage stripe and matching yellow wheels. He says he has previously owned a DH82 Tiger Moth, a DH85 Leopard Moth, a MK5 Auster and a BD-4 which he built and flew some 450 hours. His total flying time of 2000 hours was not much help, he thought, when it comes to flying an ultralight. He says he is gradually becoming its master with 30 hrs. logged to date. The fabric covering is 1.7oz Polyfiber with Stits polyspray finish. piece of local hardwood of unknown species for the landing gear has stood up to some terrible abuse. A 2.5 gal. fuel tank was installed just aft of the wing spar above the shear panel and has a simple float type gauge.
An 18hp Robin EC25 engine brings the weight to within the allowable limit. (The Robin engines are popular in Europe and are built by the makers of the Subaru automobile). He originally installed a 4-cycle horizontal twin cylinder engine which was too heavy but performed beautifully. He abandoned it because of the lack of forward visibility. There was no way to look over, under, or around it when flared for a landing. Small spoilers which were added between two wing ribs proved useless for roll control so they were removed. homemade airspeed indicator of the spring-loaded vane type was installed near the wing joint. It was calibrated by mounting it on a car and driving down the runway on a calm day.
Newsletter Editor’s Pup Flying
Sky Pup SN2028 built by Dan Grunloh of Potomac, IL made it’s first flight on July 3rd, 1986 after over two year of construction. The colors are brown and gold, the empty weight is 225 lbs. and the total cost was $2200 with a Rotax 277 engine. I have 6 hours on my Pup at this time and I am absolutely delighted with its performance. The Rotax engine starts easily and has more than enough power. The Pup was my first airplane project and my first solo powered flight. The first three flights exceeded the airtime I accumulated in my three years of flying hang gliders.
SN 2028 is very much “per plans”. All the wood was obtained locally and the fabric covering is “Gloriosa” sheath lining and polyurethane varnish. The fabric was applied using the “two dry coat” method described in the October ’83 newsletter. I attribute the extra weight to the generous use of epoxy and latex fabric cement.
For me, the most difficult parts of the project were ripping the 14 ft. fir lumber to uniform thickness for the wing spar caps, fitting the diagonal headrest panels, and attaching the fabric hinges for the control surfaces. Shaping the leading edge strip took quite a few hours as I was reluctant to use power sanding equipment.
Incidentally, my Pup was built entirely with my own two hands. I was glad to have friends who provide advice and encouragement and a very patient and understanding wife. Total construction time was about 800 hours
My first flight was a most rewarding and exciting experience. Flying my own homebuilt aircraft is something have wanted to do for about 20 years. I was not nervous or worried about the airframe because I have come to know every stick of wood and glue joint on a personal basis. Cylinder head temps were above 400°F the first few hours even though the EGT was only 1100°F. The CHT seems to be coming down as the engine loosened up more with time. The landing gear spring of white ash (instead of maple) proved it’s worth on the first landing. When I throttled back on final approach, the idle setting was too low and the engine stopped, I immediately discovered that my airspeed was too slow and made a hard “pancake” landing from 30 feet. From the descent rate, I was certain that the landing gear and prop would be damaged, but the impact was softened by the springy gear and possibly by the ground effect on the wing. There was virtually no damage. I climbed out and danced around the Pup waving to my friends at the other end of the field. I was very thankful that Steve had designed the Pup to be a very forgiving little airplane.
After about ten flights I have learned that with a CG of 4.3 inches, my Pup is still nose-heavy even after adjusting the stabilizer. With a full load of fuel (2.5 gal.) it wants to be wheel-landed. When low on fuel, it flies much better and is easier to land. I need to add some weight to the tail. A Hall airspeed indicator mounted just below and in front of the wing at the attachment joint has not proved entirely satisfactory. I’ experimenting with the mount to get it out of the high pressure area near the wing. Vibration with the Rotax can become bothersome on long flights as the “tingling” in your feet becomes numbness. Rubber mats o the floor boards reduce the problem.
Canadian Pup Ready to Fly
Sky Pup SN2236 built by Paul Pontois of Quebec Canada is shown being carefully lowered from an upstairs attic which was his workshop. The window was built to fit the dimensions of the Pup. Note the ballistic parachute mounted above the centersection. Paul has sent detail photos and drawings of the parachute installation. If you are interested, please let me know and I will gladly share the information with you. The engine is a Rotax 277FA with gear drive. He has apparently named his Pup “La Tulipe” which is very appropriate as the color is a brilliant red-orange. I must confess to a certain amount of envy as the workmanship and finish appear to be flawless. Even the photos I just received are of the highest quality. Paul is currently taxi testing and doing low hops. He will probably be flying by the time you read this. “La Tulipe” is one very attractive Sky Pup.
Feedback from Early Builders
Terry Rockwell of Susquehanna PA writes to say that he is beginning his third summer of flying his Sky Pup #1863 which was featured in the July ’84 newsletter (No. 4). He says it’s really a fun ship and he only flies when the wind is down. He doesn’t enjoy rough air one bit and goes out of his way to avoid it. He has 121 hrs. on his Cuyuna powered Pup and went through several propellers before he found one that would allow the engine to develop the full RPM. The engine will bog down and quit running if the prop has too much diameter or pitch. A Ritz 54x20 prop on a 2.25 ratio belt reduction has worked fine for him. His Pup came out a little nose-heavy and has about 4 lbs. of lead in the tail. The Pup weighs 235 lbs. and requires slight back pressure on the stick for level flight. Before flying this year, Terry replaced the fabric elevator hinges which were of the model airplane type (not the sewn method). The rudder hinges were fine but dirt and debris collect in the elevator hinge and may contribute to its wear. He also noticed that the varnish on the wing fabric seemed to be cracking along the edge of the capstrips on the ribs. He glued strips of fabric over the ribcap for reinforcement. Terry says he’s having fun taking aerial photos from his Pup but hasn’t tried changing roll of film while in flight. When not flying his Pup, he is in the process of building a Kolb Firestar.
The following passage is from a letter to Sport Flight from Dave Beres of Walla Walla WA. SN1941 was featured in the October ’84 newsletter (No. 5). Here are his own words. “My little plane is still flying, strong as ever and has just logged its 400th hour! I’m still running an old point fired Cuyuna 215 which has had two majors (two pistons) and a few seals. On that engine I have only dead sticked once, fortunately into a horseless horse pasture. The plane crashed badly once due to a sick Yamaha engine so it has a repair in the main spar of the left wing but 390 hrs. have been put on that spar. The plane is starting to show some age and patches but that just helps nostalgia. I’m on my 2nd set of tires, 3rd tailwheel, 3rd strobe bulb, and lots of engine parts. The longevity of the Pup is due to a good design, good care, and staying out of bad weather. I don’t fly in the heat of the day due to thermals and don’t fly in wind at all. Earl morning and dusk are great and I get lots of flying in during those times. My longest trip was 60 miles one way. I cruise at 43 mph and slow down to 36 or so if it gets bumpy. It’s a good solid little plane and is hangared next to a Piper Colt which I also own but can’t afford to fly much. The Pup fits the bill for anyone who loves to fly and will stay together a long time.”
Sincerely, David E. Bere
Miscellaneous and Building Tips
1. Here’s a tip from Sport Flight. The axle tubes which are usually a loose fit inside the wheels should have brass shims added to reduce wobble and prevent wear should you forget to keep them well greased. Almost two full turns of .010 inch sheet brass from the hardware store worked fine for me.
2. Paul Pontois reports that excess low speed vibration in the Rotax engine can be caused by a rich fuel mixture. Opening the idle air screw should cure the problem.
3. Several builders including myself can verify that the fuel consumption of a Sky Pup at moderate cruise with the Rotax or Cuyuna is one gal. per hour or less!
4. It has been suggested that abrasion of the tailskid from a hard surface runway can be reduced by having a welder lay down a couple of beads of extra hard material on the underside of the skid. Some type of tungsten alloy was suggested, I think?
5. It has been pointed out that some brands of polyurethane varnish claim to have an ultraviolet inhibitor or absorber. I talked with someone in the paint industry who said that virtually all reputable name brand of exterior polyurethane include UV inhibitors and other additives not present in interior varnish. Exterior polyurethane should have the words “oil alkyd resin” in the ingredients. The price will vary depending on whether the resin is derived from linseed, soybean, or Tung oil.
6. Several builders have offered a reminder that vent holes must be provided in the wing and fuselage compartments as soon as possible after the fabric is sealed with varnish. A large change in temperature or pressure can bulge and stretch the fabric. I saw my fuselage puckered inward on morning because I had sealed the drain holes with varnish.
7. A small triangular heat sealing iron available at hobby stores is very handy for shrinking the fabric in hard to reach spots. To remove air bubbles, first prick the bubble with a pin. Then, iron out gently, avoiding over-heating as steam from the latex cement will enlarge the bubble and worsen the problem.
SKY PUP NEWS
Newsletter No. 13 October, 1986
Another Canadian Pup Flying
Oshkosh ’86
Report Indiana Pup Nearing Completion
A Warning About Airspeed Indicators
”La Tulipe” Flying in Quebec
Care and Feeding of the Rotax 277
Miscellaneous
Real Adventure Right Here In Illinois
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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 to 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, all ideas, suggestions and building tips are strictly the opinion of the contributor and have not been approved by Sport Flight Engineering Inc. No warranty is made as to the airworthiness or 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. Subscriptions 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 m at (217) 569-2121 late evenings. Please keep sending your letters and photos
This issue (No. 13) marks the end of the first year of SKY PUP NEWS as a builder written newsletter. For me, it has been a very rewarding experience. As long as there is a continue interest and builders and pilots send letters and photos, I shall continue the effort. All subscribers for 1986 will receive the January issue for 1987 (No. 14). However, the newsletter is not a profit-making venture so please send your subscription for next year if you wish to be included.
It has been suggested that we, the Sky Pup builders and pilots, should form an official SK PUP PILOTS ASSOCIATION. The newsletter would be just one part of that organization. Another function might be to maintain a current directory of Sky Pups and their owners. I anyone has experience with a similar group or any ideas how we could start, please share it with us. It is up to us, the pilots and builders, to keep the design alive for the future. We are very select group of people and we should be proud because very few ultralights or homebuilt are built entirely from plans. It is a significant achievement. Like any other aircraft, the Pup has certain limitations but it’s unique combination of low cost, docile handling, and excellent performance put it in a class by itself. As for myself, I wouldn’t consider trading my Pup for any other ultralight on the market.
Another Canadian Pup Flying
Sky Pup SN2666 shown here was built by Jean-Claude Hivon from La Perarde, Quebec. The color is white with black trim and black wingtips. The name on the side of the fuselage is “L’Epervier” which translates as “The Sparrow Hawk”. First flight was just a few weeks ago with no problems reported. The engine is a 14hp Rotax twin-cylinder of snowmobile origin. He modified the engine himself for use in the Pup. He says it has minimal vibration and uses only ¾ gal. of fuel per hour. The bottom line of the rudder is angled upward slightly and wire spoke wheels are visible in the photo. Total construction time was 500 hours. Jean-Claude is a fast builder as the entire project took only 3 months. After completing the Pup, he had to wait to fly it while he earned his ultralight pilots license, a requirement in Canada. Jean-Claude built his own hangar and has a 1000 foot runway in front of his house. A pair of Mitchell B-10’s share the hangar. When all three ultralights are inside, the Pup hangs from the ceiling by strap around the center spar. SN2666 has also been equipped with skis for winter flying. Paul Pontois says there are at least two Pups flying with skis in Quebec. Jean-Claude’s English is minimal so Paul has provided some details and the translations for this article
Oshkosh ’86 Report
Only one Sky Pup was shown and flown at Oshkosh ’86. Gerry Coppock from Escanaba Michigan returned for the second year with SN 1173 “Gerry’s Dog House” which was feature in newsletter #7 and #9. I had hoped to have my Pup there but with only 6 hours of airtime and no trailer, it just wasn’t possible. Gerry had built a large enclosed trailer which also serves as camper when attending airshows. The Pup was flown frequently during the week and attracted much attention even when not flying because of its light-hearted trim scheme and detail. Gerry complains that many aircraft have dull, drab colors and tirm. His philosophy is that flying should be fun and his plane is decorated accordingly. Sky Pup enthusiast Dale Fullerton suggested that original personalized trim, decorations, logos, etc. could well become trademark of Sky Pups everywhere. Gerry surprised all of us at Oshkosh because he told no one that he had painted "Sky Pup" in large letters on the bottom of the fuselage. It can't be seen when the Pup is on the ground but shows up very well when coming in for a landing. We should be very thankful that Gerry has had the willingness and dedication to bring his Pup to Oshkosh these last two years. He alone is responsible for keeping the Sky Pup idea alive among the convention attendees. A considerable number of builders and plans buyer stopped by to see the Pup and visit with Gerry. I'm certain we will have a lot more Pup attending next time
Indiana Pup Nearing Completion
Donald Diggs of Monon, IN reports that his Rotax powered Pup is nearing completion. the color is Navy blue with white trim. Unique features include a foam and plywood engine cowl with windshield and a 2 gal. aluminum fuel tank installed behind the main spar under the centersection shear panel. He hopes to be flying by early next spring. We live only 100 mile apart so we may fly together someday
A Warning About Airspeed Indicators
Regardless of the kind of airspeed indicator you install on your Pup, you must calibrate you installation by flying between two points a known distance apart and recording the time. Choose a day without turbulence and make several passes upwind and downwind and average the results. Even if your airspeed indicator checked out fine when sticking out the car window, it may be way off when mounted on the airplane due to aerodynamic effects of the wing, propwash or vibration. Also you should make test runs at several different airspeeds to ensure that it works properly throughout the range of flying speeds. I have experimented with a Hall ASI mounted in various positions and have observed a variety of strange effects. In some cases it was perfectly accurate at 40 mph but wouldn't read over 45 mph even if I flew 60 mph. Several builders have recommended that plumbing be installed in the wing so that a pitot type ASI can be installed in the outboard wing panel well beyond the effect of the propwash. I wish could make more specific suggestions but every instrument and airframe combination is unique. You must work it out for yourself. You should be able to fly safely without an airspeed indicator, but don't be fooled by one that is inaccurate especially at the higher airspeeds
“La Tulipe” Flying in Quebec
Sky Pup SN2236 mentioned in the previous newsletter made it's first flight just prior to Oshkosh '86. It was built by Paul Pontois, 1890 Range des Chutes, Ste-Ursele Quebec (J0 3M0). He has over 15 hrs logged to date and says that it "flies like a wonder". The longest flight was 60 miles cross-country to a glider club field. The glider pilots were very interested in the Pup which was the first they had seen. The shape of the vertical tail was changed slightly for aesthetics and the turtleback has two equally spaced foam supports instead of one. This pup has a custom built 3 gal. fiberglass fuel tank of trapezoidal shape. Paint pigment was added to the epoxy to give the tank color. The original attachment was with aluminum angle which were glassed into the corners of the tank but they could not stand up to the vibration. (All fuel tanks whether metal or fiberglass are best attached with straps of metal or webbing. Hard attachment points will eventually crack and develop leaks.) Paul reported that he cracked a lower longeron at the gear axle on an early flight due a hard landing. His Rotax powered Pup came out somewhat nose heavy. So did mine and quite a few others. The recommended fix is to lower the leading edge of the horizontal tail by reducing the spacers used at the front mounting bolt. Adding weight to the tail has also been tried. Springs or bungee tension devices in the control system are not recommended. Paul suggests reducing the down-thrust of the engine by adding washers under the front engine mount rubber stoppers. This has proven very effective on his Pup and on mine. Now we cruise hands-off, climb with forward stick pressure, and glide with slight back pressure. (I previously held light back pressure all the time.) With the Rotax, this adjustment is quite sensitive. Paul says there are at least five Sky Pups completed and flying in Quebec. Quite amazing when you consider that most people there do not speak English and that the Pup wasn't advertised in Canadian ultralight magazines
Care and Feeding of the Rotax 277
Here are some tips from a forum at Oshkosh '86 given by Ron Shettler, the North America distributor of Rotax engines. According to Ron, the most important engine instrument is the tachometer. The engine must turn the specified RPM at full throttle to run properly. This will require a correctly matched propeller, carburetor, and exhaust system. These conditions must also be met for proper break-in to occur. Do not use extra oil during the break-in period. He says a common mistake is to attempt to re-jet the carburetor based solely on the indication from cheap gauges or those which are affected by vibration. If you have other indications such as spark plug readings or poor engine operation, then check for a clogged air or fuel filter, bad fuel, mismatched propeller or incorrect timing. The engine should run properly with the carburetor as set up by the factory. The most important carburetor adjustment is the fuel bowl float level. When removed, the bowl should be slightly less than one-half full of fuel. Oil currently recommended are Bel-Ray UL-1 and "AV-2" which is available from CPS and L.E.A.F
It is important to use fresh high quality fuel which can be leaded or unleaded but with no alcohol. Fuel composition varies widely throughout the country and all fuels and oils are not compatible. You must find a combination which works well in your area. Another mistake with the Rotax is failure to check the timing in the first 20 to 50 hours of operation. As the point wear-in, the timing can change and cause serious problems if not corrected. If you have a truly unexplained engine stoppage, the exhaust manifold should be removed and the piston checked for scoring. The engine may run after a partial seizure but it will get worse each time the engine is worked hard and can lead to repeated engine stoppages
Miscellaneous
My thanks to Wm. Stacy from Buffalo Iowa who sent me a "fresh" batch of rubber stoppers for my engine mount. My original stoppers, though new, may have already been several years old. They lacked flexibility and did not absorb vibration well. I've also learned that soft "pure gum" stoppers (white) can be ordered from laboratory supply companies.
Note: The following is an addendum to the volume 13 Sky Pup News
REAL ADVENTURE RIGHT HERE IN ILLINOIS
Are you bored with watching television? Does bowling and back yard barbeque lack the thrills and excitement you crave? No need to climb distant mountains or canoe wilderness rivers. Just get yourself and your ultralight and join us for a week-end cross-country flight.
On Sunday September 28th, four members of the lllini Skyriders (Gary Buck, Greg Dembeck, Marion Evans, and Dan Grunloh) departed from Busboom's on a 55 mile flight to the Fosdick RLA near Fairbury where member Jim Steidinger keeps his Easy Riser and his Ercoupe. Other ultralights from the northern part of the state were also invited. I had heard that a pair of Easy Risers had flown in on Saturday afternoon so I really wanted to ''go for it". The early morning weather report gave a line of thunderstorms 200 miles northwest with a 30 percent chance of reaching our area in the afternoon.
At dawn I flew the 10 mites from Homer to Busbooms under clear skies with a light tailwind The weather seemed perfect and I calculated that even if the storm did come this far south, we would arrive at our destination long before then. The air was smooth and we made good groundspeed on the first leg so we bypassed our 1st potential fuel stop at Patton and continued on to Roberts. Weldon Garrelts keeps his BI-RD at a field near there. We cruised alone at different altitudes watching the landscape roll by. Marion Evans seemed to prefer a low altitude when following roads. At times I wonder if he's trying to read the road signs. Greg likes to be up much higher where he can get the overall view. Weldon’s BI-RD had been damaged in a windstorm two days before and we could see the remains of the hangar roof scattered across the field near the strip. After landing we topped off the fuel tanks and inspected the rare old classic Luscombe Sedan (a 4-seater) which is based there. By the time we arrived at Roberts there was a definite layer of hazy clouds to the west and signs of cumulus development behind it.
Our final destination was only 20 minutes away so instead of getting a weather update or turning back towards home, we decided to keep on going. After take-off, Gary Buck in his phantom joined our formation. He departed Busbooms somewhat after us and actually flew the entire trip non-stop. It was becoming obvious that some weather was headed towards us with the tops of more and more cumulus showing above the haze. We were also flying towards it. Suddenly a bright blue lightning bolt snapped to the ground at the front edge Of the clouds. It seemed to be about 10 miles away and at a lower altitude. Finding our destination airfield somewhere ahead suddenly seemed much more urgent. Greg was up high and ahead of me and seemed to be going too far north. Marion was down on the deck following road signs as usual. If the Fosdick RLA didn't show up soon we would have to land in a field and sit out the storm. Then I saw a green strip below us with someone waving something bright orange. I made a broad sweeping turn to signal the others did a low flyby to check out the runway. There was Jim Steidinger and Chuck Stevenson. They thought we were going to fly right by them which we almost did.
After landing we learned that Chuck had driven down from Wisconsin leaving his Eindecker behind because of the weather. The Easy Risers had beat a hasty retreat just 30 minutes before we arrived, Not long after the ultralights were tied down securely between some sheds the wind and rain arrived. Then as if to reaffirm its superiority over us it followed up with some hail. Sober faces peered out from the shelter of the machine shed. Though we were never in any real danger, had we been 30 minutes later it could have been serious. The gust front was strong enough to have made landing difficult. I realized then that my optimism and enthusiasm had encouraged others to take unnecessary risks. The period of rain was short and we soon dried out. Jim and Chuck drove us into the nearby town for some food and fuel. While there we browsed through the shiny chrome and good-looking women at a custom car show in the city park. When asked how many hours of work he had put into his dream car, one builder said he stopped counting after 2000 man-hours.
Back at the airstrip the storm clouds had moved on and the sky was beginning to clear. Though I was content to stay on the ground until late afternoon, a headwind was building and the others felt we should begin the return flight. After take-off it became obvious that thermal turbulence was also beginning to develop. I slowed down to avoid wind gust loads and watched the landmarks slow to a crawl. You get to know a little town or grain elevator very wel1 when you can watch it for 20 minutes in a straight line flight. There was a definite difference between the groundspeed of my Sky Pup and of the Phantoms the other pilots were flying. Soon they were only faint specks far ahead. There were plenty of 1andmarks so navigation was no problem.
By the time we landed at Paxton, our next fuel stop, there was a scattered layer of puffy cumulus stretching to the horizon. The air was definitely getting rowdy but everyone landed safely. The wind was stronger now and taxi turns with my taildragger were becoming difficult. I was certainly glad to be back on the ground and felt like staying there for awhile. We rested, visited, had a cool drink, and topped off our fuel tanks. After a while Gary Buck says, ''Let's go. It's not going to get any better and we have just flown in these conditions, so we know we can do it.'' No one moved. His previous training and experience in sailplanes may have helped him adapt to turbulence. Or possibly he has no nerve endings left. He took off, flew the pattern and made a 1ow pass to give us encouragement. I reluctantly followed the others into that roller-coaster sky. I was convinced that they were getting even with me for leading them towards the thunderstorm. This part of the trip wasn't that much fun. The sky was full of puffy growing cumulus clouds that usually say to you ; "Do not fly your ultralight now. Strong thermal turbulence.'' Flying slowly a headwind and bobbing like a cork in the ocean, the landmarks seemed to stand still. Holding an airspeed just above the stall eliminated any worry about structural overloads in the gusts. The Sky Pup just mushed through the roughest bumps. Plenty of altitude throughout the flight gave the necessary safety margin. I flew into a large updraft and watched in fascination as the houses and farms below rapidly grew smaller and smaller. The thermal finally kicked me out with a bump and I continued on enjoying the view in spite of the bumpy ride.
After a long long time our home field appeared and when I descended to enter the pattern, I was surprised to see how much the trees below were bending in the wind. It was at least 15 mph because I had taken almost one hour to go 25 miles. Marion Evans, who had landed earlier, said he saw me approaching from the north and then checked a few minutes later and I seemed to be in the same place. What's more, this was going to be a direct: crosswind landing in a 2-axis ultralight. I was lucky. With a strong crab angle I approached the strip and managed to land between the gusts, skidding on one wheel to a stop with no damage whatsoever. It was too windy to taxi my Sky Pup crosswind back to the hanger. I had to shutdown, climb out and push it down the runway by hand. Later, I kept looking up into the sky and asking, how could we have flown in these conditions? I can't believe it's even possible". Surely no intelligent person would fly an ultralight in this much wind.
I think we were lucky and I hope I learned my lesson. One lesson was that I must avoid impressing my optimistic view of the weather picture on my fellow pilots. Just because some-one will follow you doesn't mean that your assessment of the forecast is correct. Also a strong case of get-home-itis caused us to fly in conditions we normally avoid . I probably flew much slower than necessary in the turbulence and thus increased the length of time I was exposed to the rough air.
In spite of all the rough spots, it was a challenging and rewarding day. For me, it fits into a special category of four or five flights I have made this year. After landing I've said to myself, ''That one flight alone was worth the two years it took to build the airplane. ''That's what real flying is all about. Adventure .
Now comes the real question of this story . What did you do on the last Sunday in September? Or whenever? Was it an exciting adventure? Did it make you feel invigorated and really alive? Think about it.
Written by Dan J. Grunloh
President EAA chapter UL-30
SKY PUP NEWS
Newsletter No. 14 January, 1987
A Golden Pup from Iowa
Fresh Fish via Sky Pup Air Freight
Ideas for Trailering the Sky Pup
First True Litter of Pups is in Kansas
Saskatchewan Pup Nearing Completion
Building Tips
Miscellaneous
Transporting Your Sky Pup with a Pick-up Truck
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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 to 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, all ideas, suggestions and building tips are strictly the opinion of the contributor and have not been approved by Sport Flight Engineering Inc. No warranty is made as to the airworthiness or 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. Subscriptions 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 m at (217) 569-2121 late evenings. Please keep sending your letters and photos.
Welcome to another year with SKY PUP NEWS. If you subscribed in 1986 and missed an issues please let me know. Subscriptions are based on the calendar year so even if you joined us late in the year, you should have received all four issues. Your renewal, however, will not be considered past due until 12 months after your last payment was received. Subscribers will be notified individually before their name is dropped from the mailing list. This issue of SKY PUP NEWS contains a number of firsts for the Sky Pup design. These include the first time two Sky Pups flew together, the first Pup to win a contest at a fly-in, and the first Pup to be used for ice fishing.
A Golden Pup from Iowa
Paul Rasmussen of Des Moines, Iowa built this Rotax powered Pup which is yellow gold with black leading edges and black wheels. He has made about 20 flights to date totaling 10 hr. airtime. Paul has a student pilot certificate with 16 hrs in a Cessna 172 including an engine failure on his first solo X-C flight. Who said "real" airplanes are safer? The initial test Flying was done by Bob Beaver from Indianapolis. Bob is a friend of Steve Wood and had also flown the prototype. Empty weight is 210 lbs and Paul weighs only 155 lbs so performance with the Rotax engine is just unbelievable. He only uses 3/4 throttle for take off! The airframe was built from a pre-cut wood kit from Wicks Aircraft Supply. (some of us who scratch-built our Pup have a tendency to use too much fir. Wicks supplies spruce wherever permitted which helps save weight. Pine can also be used.) The Pup took 15 months to build in the basement of a rented duplex. He had to remove a sheetrock wall to get the bird out of the nest. The wall was quickly replaced and the landlord never knew. Paul says the outboard leading edge was damage when a friend who was taxiing the Pup ran off the end of the runway and struck a telephone pole. From the force of the impact he thought the wing would surely be totally destroyed. The injury was repaired with foam and plywood and the leading edge has a splice but now the wing is just as strong as ever. Paul transports his Pup on the back of a pick-up truck which he say works just great. During the flying season it's kept in a hangar. This winter he plans to install custom aluminum fuel tank, instrument panel and cowling, and a hand-deployed chute. Here' a tip from Paul for those of us who are using the Rotax engine. Foam tubular pipe insulation was attached to the rudder bar which prevents the feet from going to sleep on long flights due to vibration
First True Litter of Pups is in Kansas
A total of five Sky Pups are completed or under construction in the Wichita, Kansas area. The location seems quite appropriate as this is where the prototype was conceived, built and first flown. Shown here is the first known photo of two Sky Pups together. The Pup on the left was built by Bus Broadbooks of Goddard KS. The color is bright red and the engine is a Rotax 277. Unique features include flat wingtip end plates and wing gap covers which are long strips of fabric glued to each surface and joined with a zipper. Bus has installed a Scott steerable tailwheel and a pitot type airspeed indicator. A plastic fuel tank is recessed into the forward deck and supported by a webbing harness. An ingenious feature is a storage compartment in the headrest behind the seatback bulkhead. A small door was cut into the triangular headrest side panel (not the diagonal panel). Bus says it works great for small items including baby food jars of 2-stroke oil. (On the subject of storage compartments; another builder cut a door in the headrest under a cushion which was attached with Velcro; I have found the centersection D-cell very handy for small items; and finally, a builder cut a door low in the fuselage side pane to gain access to the area behind the lower seatback. You should be cautious about cutting into panels which may be important for strength)
Next in the litter is the light blue and yellow SN 1215 on the right which was built by Mike Huddleson from Wichita. Mike, a high school woodwork teacher, saw the prototype airframe in early '83 and began construction later that year. When taxi testing was begun in June '85 a crack developed in the centersection due to an inappropriate splice in the spar cap. After repairs were completed, the historic first flight took place Sept. 15, 1985 in Douglas, KS. the traditional shirt tail cutting followed the happy occasion. Since that time, many flights have been taken including a trip to the fly-in August 2nd, 1986 to Gossel KS where Mike and Bus flew together. Mike says beginner's luck brought him first place in the bomb drop contest. His Cuyuna powered Pup cruises at 47 mph at 3/4 throttle and burns 1-3/4 gph of fuel. It required light back pressure on the stick at all speeds
The third Pup completed and flying was built by Paul Whaley from Eldorado KS. I have few details and no photo but this Pup is reportedly finished in J3 Cub colors and is powered by a Kawasaki 340 engine. Though possibly heavier than the Rotax, Bus also plans to try this engine on his Pup to eliminate the vibration inherent with the Rotax. Pup #4 built by Mike Sinclair of Eldorado KS is nearly completed and will have Rotax power. Pup #5 is under construction by Lew Heibert from Hesston KS. Hopefully some day in the future all five Pup will get together for a formation flight. What an incredible sight that would be!
Saskatchewan Pup Nearing Completion
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This Pup is being built by Brent Adams of Saskatoon Sask. The fuselage is dark blue with red trim. In addition to the ferocious looking jaws, a bright red tongue is painted under the front of the fuselage. Fabric covering of the wings and engine installation are all that remain. Brent says instead of drilling holes in lab stoppers for the engine mount, #6 bung stoppers from home brewers supply already have a perfect sized hole in them
Fresh Fish via Sky Pup Air Freight
Paul Pontois reports he made a visit to Jean-Claude Hivon in La Perade Quebec on Sunday, January 4th. The weather was sunny, calm and only 5 degrees F. When he arrived a ski equipped Mitchell B-10 was turning big circles overhead and the Pup was getting ready to take off. Sky Pup SN 2666 was featured in the previous newsletter. Jean-Claude has mounted skis on his Pup and frequently flies to the frozen St. Lawrence river 5 miles away where ice-fishing is very popular. Like many local residents, they have a fishing cabin set up on the frozen river
The Pup is very convenient for bringing the day's catch back to the farm for supper. Probably the first time a Sky Pup has been used for ice-fishing. Paul spent the day with the Hivons and reports that the Pup handled take-offs and landings beautifully. These folks are definitely a flying family as they have a Sky Pup, two Mitchell wings, and another Pup soon to begin construction all by brothers and cousins. Paul says that when he left, the Sky Pup and Mitchell were still turning around overhead in the orange sky of evening twilight
Ideas for Trailering the Sky Pup
These pictures are presented to encourage you to build a trailer for your own bird. With trailer, you will be able to attend distant airshows and may be more willing to attempt long cross-country flights. Many ultralight pilots are reluctant to leave the home field if they have no way to retrieve the aircraft should it be grounded due to mechanical problems or unexpected bad weather. The photo on the left is from Roy Thomas of Belfast, Maine. Note that thin wood strips are clamped on the tail surfaces to keep them from banging against the stops. A wood and foam cradle secures the wings on the back of the truck. The photo on the right shows the rig used by Gerry Coppock of Escanaba, MI to bring his Pup to the Oshkosh '85 convention
The simple trailer was built up from an old car axle and the wings are bolted on top of the truck. A welded steel arm projects above the cab of the truck and has brackets and holes to match the wing spar attach fittings. At Oshkosh '86 he had a fully enclosed trailer which held the wings above the fuselage and also used the attach fittings as the mounting point. This method seems logical as the fittings are the strongest part of the wing. It might be advisable to use aluminum pins instead of steel to prevent wearing the holes in the fittings on bumpy roads. I have considered a trailer with the wings mounted on the sides but it may have to be almost 8 feet wide! Let's get some trailers built out there so we can have more Sky Pups Flying at Oshkosh this year!
Building Tips and Miscellaneous
1. If you have trouble finding Blue Dow foam in your area, Corning pink foam (which is called "Foamular") is reportedly an equivalent substitute.
2. Closes cell foam sleeping pads sold in camping supply stores are excellent for seat padding especially where headroom is a limiting factor. Usually less than one inch thick, one or two layers of this dense foam will provide plenty of cushion.
3. When covering the turtleback with fabric, you will discover that a small piece of foam needs to be fitted around the front fin spar between the aft ends of the stringers to provide a surface for bonding the fabric. It is visible in photos in the construction manual but is not shown in the drawings or mentioned in the text.
4. Builders planning to use the Rotax engine should get a copy of the Rotax installation drawings which are available from Sport Flight. The breadboard dimensions are different and the engine offset is opposite from the Cuyuna if a gear-drive is used.
5. It is important that the four engine breadboard mounting bolts be kept tight. The short steel tube spacer should be clamped firmly between the washers as shown in the plans. Any looseness will add considerable vibration. I always check during preflight to be sure the upper washer cannot be turned with the fingers.
6. In the next issue, we will have an update from Roy Thomas of Belfast, Maine whose Pup has logged 25 hrs of airtime to date. SN 2469 shown below was featured in the April '86 issue.
7. I am pleased to announce that my own Pup SN 2028 won a very nice trophy for "Bes Ultralight" at an airshow in Danville, IL on Sept. 14th, 1986
Note: The following sketch was included as an addendum to volume 14 of the Sky Pup News.
SKY PUP NEWS
Newsletter No. 15 April, 1987
Konig Powered Pup Flying
More Sky Pups Completed and Ready to Fly
Update from Leroy Thomas
Illinois Sky Pup Reunited with Owner
Miscellaneous
Accident Reports
Hinge Cross-section
Rudder Bar Pedal Modification
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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 to 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, all ideas, suggestions and building tips are strictly the opinion of the contributor and have not been approved by Sport Flight Engineering Inc. No warranty is made as to the airworthiness or 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. Subscriptions 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 m at (217) 569-2121 late evenings. Please keep sending your letters and photos.
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Dear Subscriber: Sorry this issue is going out over a month late. Letters and photos have been slow arriving as fewer Pups are taking to the air in late winter and early spring than at any other time. My own tendency to delay work on the newsletter until it is already overdue is also to blame. A majority of subscribers have given no indication of the status of their project. Let' hear from more of you!
Konig Powered Pup Flying
Newton Borden of South Weymouth, Mass. has completed and flown his Pup SN2625 which is powered by a Konig 3-cylinder radial engine. The project was first reported in the Oct. '85 newsletter (No. 9). An experienced pilot, Newton is 63 years old and flew for a local operator everything from crop-dusting to student instruction. He also has some building experience as he previously built a Mitchell wing. The Konig engine swings a direct drive 42 inch ground adjustable prop at 4200 RPM to produce 24 HP. The smooth running lightweight engine has electric start and he has mounted the motorcycle type battery under the engine cowling. He has about 5 hrs on the engine and says the prop really "bites into the air". He may have to move the muffler as it's rather noisy in it's present location. INAV Ltd. of Oshkosh, WI may be the current source for the slightly expensive engine. It has been used in the "Moni" motorglider. SN2625 was covered with zero porosity rip stop Dacron with two coats of clear polyurethane. It has a blue fuselage and orange wings. Empty weight was 212 lbs and the CG came out to 7 inches. A 3.2 gal fuel tank serves as the headrest and an additional tank on the forward deck brings the total to near 5 gal. A steerable tailwheel is mounted on an aluminum leaf spring. This Pup has a very detailed and complete instrument panel and the inside of the cockpit was lined with thin plywood. A wire-spoked wheel was bent on an early hop so he has changed to moped motorcycle wheels, bearings, and brakes which added an additional 12 lbs. A single brake lever is mounted on the stick. There is no provision for differential braking
Newton says his first flight was unplanned as he accidentally became airborne during a fast taxi test. The small diameter prop produced more thrust than was expected. At the time he had no helmet, inadequate fuel, and no seat belt installed in the Pup. It's easy to understand why you should never fast taxi an aircraft that is not completely ready to fly! Turnbuckles must be safety-wired even for engine break-in as they will unwind very quickly due to vibration. Newton plans to be at Oshkosh this year but may have to leave the Pup at home until he can obtain a adequate trailer and tow vehicle
More Sky Pups Completed and Ready to Fly
Harry Grape of Seattle, Wash. sent photos of his Pup SN2797 prior to fabric cover. The Pup is now completed and may be flying by this time. The engine is a Rotax with Hegar belt drive and 54x24 prop. Harry is a cabinet maker by trade and says that some parts of the project were difficult for him. His photos show a tailwheel aft of the normal skid and a custom fiberglass fuel tank in the centersection D-cell. Fabric covering was a problem as he had previously worked with Stits and had covered a Tailwind and a Mach 07 with no problems. For the polyurethane finish he used "Varathane Ultraplastic Super 102". It is water cleanup, has UV absorbers but is expensive.
Brent Adams of Saskatoon, Sask. reports the first flight of his Pup will be delayed a few weeks due to an unusual incident. His wings have been airborne though the pilot and fuselage did not leave the ground! While transporting the wings to the airport, a gust of wind broke the ropes and blew the wings off the back of his truck. They both reached 30 ft of altitude and easily cleared a passing truck. Damage was limited to the leading edge and crushing of some nose ribs. One leading edge fitting was torn off. The aft wing fabric was not damaged and only the wingtips will have to be recovered
Greg Pardee of Owosso, Mich. writes to say that his Pup, SN2294, is completed and ready to fly. Construction was begun in January '86 with a Wicks materials kit which he recommends highly. The engine is a Rotax with 54x34 prop. He has a problem with oil spray coming from the vent tube of the gear drive. The exhaust system is flex tubing attached to a 3 lb muffle from a small 4-stroke engine. The fabric cover is Stits 1.6 oz Dacron and the finish is 3 coats of yellow polyurethane sprayed on. Only 2 gal were needed for the entire airframe. Empty weight is 208 lbs. The only modification was the lower longeron at the gear axle was double thickened with 1/4x3/4 fir
Francis Sheffield of Lake Placid, NY wrote to say he completed his Pup last year but only has made some low altitude hops so far. The engine is a Zenoah 20HP with belt reduction. custom engine mount was built which raises the engine enough for good ground clearance of the prop. This engine was used extensively on early "Eagle" and "Vector" ultralights and others and should be available on the used market
Paul Rasmussen of Des Moines, Iowa (issue No. 14) reports he has his Pup back into the Air this year with some modifications. He installed a plywood engine cowling and a ballistic chute which together added an additional 20 to 25 lbs. He reported that the added weight had noticeable effect on the flying and landing characteristics. He also felt that the parachute canister mounted above the centersection added a nose-up trim as he had to hold more forward stick in cruise than previously
Other Sky Pup builders known to be ready to fly or already flying include Larry Meyer from Camrose, Alberta, Donald Diggs from Monon, Ind., and Brian Helsapple from Seiad Valley, CA
Update from Leroy Thomas
This red, white, and blue Sky Pup from Belfast, Maine was first reported in the April '86 newsletter (No. 11). Leroy says he had a very enjoyable summer with SN2469 until cold weather set in. There was no damage except for a few broken spokes in one of the wire wheels. The initial test flying last year was done by a local licensed pilot as Leroy had no experience or training and says that he is rather heavy. The test pilot weighed 160 lbs and gladly signed a liability waiver (two pages) which was written up by a lawyer. Leroy offered to share a copy of the waiver if anyone is interested. At first the Pup was trailered to the Belfast airport for the initial flights but later the pilot would fly it back and forth from his hayfield to the airport only 8 miles away. Leroy said he would follow in his pickup truck like a mother hen with a CB radio and a can of gas. The Pup has over 25 hrs logged so far and says he enjoys it very much. He has been very satisfied with the 2 gal metal gas can strapped down on the forward deck on a piece of foam padding and a plastic tube sight gauge. The cylinder head temp of the Rotax goes over 400 when climbing (so does mine) so he constructed a cowling around the head to improve cooling. It did not help as much as he expected. He uses Castrol 2-cycle oil at a ratio of 40:1. The specs call for a 50:1 mix and the oil should be of low carbon content. The extra oil when burned, produces additional heat and this could be a factor in cooling problems. Recently it has been announced that the free-air twin cylinder Rotax engines need a cowling for adequate cooling of the back cylinder. I wonder if it would help also on the single cylinder 277. Also on this subject I have noticed a photo of the new TEAM Hi-Max at Lakeland, FL this spring showed a cowling installed on the cylinder head of their free-air Rotax 277. We need t investigate this subject further
Illinois Sky Pup Reunited with Owner
Sky Pup SN1834 shown here was built by Allan Mays of Normal, ILL and is powered by Cuyuna 215 with a 2.25:1 belt drive. The colors are blue and gold with black wheels. Over year ago, I saw this photo which had been received by Sport Flight. I was unable to locate the owner and builder. As it turned out, Allan had moved to Arizona for a time leaving his bird in storage in Illinois. He returned to Illinois and has resumed flying his Pup which has 15 hour logged to date. He has made several cross-country flights and his longest flight so far was 1:15 min. Each flight has entailed fitting and removing the wings as it is presently stored in his garage. He has his own 100x1000 ft runway and has recently converted an old machine shed to a hangar so he hopes to get more flying in this year
Miscellaneous
If you plan to attend the Oshkosh convention this year, look for Sky Pup builders to be camped at "Ollie's Birds Eye View" campground just outside the ultralight entrance which is gate #7A ( will definitely be there with SN2028). Camping is all around the house and barn which is about 50 ft from the fence around the ultralight area. The rates are very reasonable and space is almost always available. No reservation needed
It is normal for the wing attach bolts to be a very snug fit in the wing fittings. They will loosen up a little with time. I have found that insertion of the bolts is much easier if a thin film of oil such as a silicone lubricant is applied to the bolts
After about 9 months of flying and 40 hrs logged on SN2028, I have discovered several maintenance items which may be of interest:
* Plywood on the wing attach uprights showed signs showed signs of weathering an mildew. There is a tendency to apply insufficient varnish on vertical surfaces in a attempt to avoid unsightly runs and drips. Erosion from prop blast might be a factor in this location. I noticed Gerry Coppock also had this problem with his Pup
* The throttle control inner cable had a buildup of rust and corrosion apparently due to rain during occasional outdoor storage. It had been lubricated only once during initial assembly. It had never given any problem but would have eventually stuck throttle "on"
* Inspection of the aft ends of the control cables showed rust and corrosion of the cadmium plating on the bolts under the stainless steel cable bushings. The bushings were partially stuck on the bolts such that they would not rotate freely. Periodic inspection and lubrication at these points would be advisable. Also, I noticed the bushings tend to slide to one end of the bolts and stay there. I added spacers cut from thick-walled plastic tubing to keep the bushings centered on the bolts.
ACCIDENT REPORTS
Several subscribers have asked that they be informed of any accidents. Their concern is that there might be problems with the airframe or any recurrent problems of pilot error. I can confidently report there have been no problems with Sky Pups which have been properly constructed and flown. I have heard of three accidents which involved pilot error.
Leroy Thomas reported that a builder from Farmington, Maine wrecked his Pup in 1986 while on and early flight. The licensed pilot with 50 hrs. experience was doing short hops from a 3500 ft. runway, At 30 ft. of altitude he noticed he was running out of runway and made a left turn and struck trees near the end of the runway. Both wings were sheared off near the tiedown straps and the cockpit area was badly cracked. The Pup settled down from the treetops and the pilot walked out of the woods unhurt before anyone arrived. Apparently he does not plan to rebuild his Pup as he is now constructing a Pietenpol. The cause of the accident was failure to add power and begin climbing promptly when it became evident there was not enough runway remaining for a landing.
A 61 year old pilot from Clinton Arkansas reported that he suffered a broken foot and other minor injuries and severely damaged his Cuyuna powered Pup in October ‘86 while on it's first flight. The accident was attributed to pilot error. However, another builder had previously contacted Sport Flight expressing concern about extensive changes and modifications and substitution of materials on this Pup. Poor workmanship was also suspected. According to the pilot, he made a takeoff, climbed to 100 ft. or more, and made two left turns. He then throttled back and the Pup nosed down and impacted the ground from about 100 ft. of altitude. The left wing hit the ground first and was sheared off. The landing gear and bottom of the fuselage was severely damaged. The fuselage was intact aft of the seat area. The prior experience or training of the pilot and the CG of the aircraft were not reported. Presumably power was not added to attempt to slow the descent. The pilot felt the accident was caused by reducing power too much after he leveled off and by erroneous airspeed information. It is my experience that the Sky Pup is quite suitable for beginners with little experience and that an airspeed indicator is not an absolutely mandatory item.
Though the actual cause of the accident may never be known for certain, I feel the most common error for a beginner would be failure to maintain the proper pitch attitude for the specific condition of flight. Normal climb is about the same as the 3-point position on the ground. Cruise is upper longeron approximately level. Normal glide is distinctly nose-down. If you spend a lot of time sitting in the Pup on the ground with the tail down, you may try to keep that attitude while in normal flight. (that is exactly what happened to me). If your bird comes out nose-heavy or your airspeed indicator reads high, you will be tempted to fly nose-high to avoid going too fast. If you then reduce power to land and do not let the nose come down, the Pup will enter a steep mush. The best indication of proper airspeed is a pull back on the stick should raise the nose and produce a slight ballooning upward. If the nose comes up but the sinking feeling increases, your airspeed is too low! Also my advice is to climb to at least 400 ft. of altitude before initiating turns on your first flight and leave some power on for your first few landings.
A third accident I have heard about was apparently a fatality, possibly in 1985, in Canada. A pilot struck power lines on the landing approach from his first flight. Investigators attributed the accident to pilot error. During the investigation they contacted Sport Flight to determine if the aircraft had adequate rudder control travel to have avoided the obstacle. Apparently it did. A reminder to other builders about control surface travel and proper hinge shaping was published in the July |85 newsletter (No. 8). The principle details are shown here for anyone who may have missed it.
Editor’s note: The NTSB has one report on the “Storey Sky Pup” of a fatal Sky Pup crash in Florida due to the separation of the wing attachment bracket. This was almost certainly due to faulty building technique. The editor is also aware of a fatal Sky Pup crash in Ohio where witness describe the wings collapsing. The pilot’s family burned the plane before it could be examined to determine what caused the crash. BTW this plane had previously made a water landing in the Ohio River due to an engine out.
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Original Newsletters edited by Dan Grunloh, electronic edition compiled by Edwin Lelieveld and Roger Ford.
