Information on Skypup
John R. Sell
Does anyone know if there is a builders group for the "Skypup" or if
Sportflight avaition is still around? I aquired plans years ago and am
getting ready to build. I would also like to communicate with
builders/flyers. Any info is appreciated. Please E-Mail to
clu...@ix.netcom.com Thanks John
Gil Leiter
John, I am also interested in the Skypup. I have been in contact with a
number of others interested in the Skypup on the ultralight list
recently. Have been discussing possible modifications. Do you have a
complete set of newsletters? They are available from Dan Grunloh.
I accidentally sent a post to the entire ultralight list (rather than
just to an individual) and received a lot of response. It would appear
that there might be enough interest to form a small, informal, Skypup
group at this time. I plan to send out a note soon inquiring if others
are interested. If you are not part of the ultralight list, I advise
that you subscribe as there is a lot of interesting UL things going on
there.
Reply to me by e-mail for more info
gil leiter
MAPLEWOOD, MN
Daniel Grunloh
In article <56b1ir$f...@sjx-ixn8.ix.netcom.com>,
clu...@ix.netcom.com(John R. Sell) wrote:
>Does anyone know if there is a builders group for the "Skypup" or if
>Sportflight avaition is still around?
Here is a copy of the text file from my homepage.
See also some pictures at the URL shown in my signature.
++++++++++++++++ THE SKY PUP ULTRALIGHT +++++++++++++++++++
The Sky Pup is a wood, foam, and fabric, plans-built ultralight.
The configuration is a conventional high wing tractor monoplane. The
design originated in 1982 as a response to the wire-braced tube and
dacron ultralights of that time. It was designed from the start to
be built from low cost materials which could be obtained locally.
Wood members are sized for Douglas fir and pine which can be
carefully selected from a local lumber yard. The foam panels used
for the fuselage and wing ribs are extruded polystyrene (blue Dow)
foam. The fabric was pre-colored dacron from the local fabric store.
Only the hardware and metal parts must be obtained from aircraft
sources. By minimizing the cost of materials, it was proven that a
Sky Pup airframe could be built ready to fly, less engine, for $1000.
The Sky Pup was designed by a trained aeronautical engineer,
Stephen K. Wood of Sport Flight Engineering Inc., P.O. Box 2164, Grand
Junction, CO 81502. Phone (907) 245-3899. The original prototype was
built to demonstrate the use of wood and foam beams in aircraft
structures. It was so successful, he was compelled to offer plans for
the design which are very well drawn and complete, and are still
available for $70.00.
The design was conceived before the weight limit of FAR103 had
been announced. Many industry experts expected the final weight
limit to be only about 220 lbs instead of the actual 254 lbs which
was eventually allowed. To acheve the 220 lb. limit, it was decided
to omit alerons and design the craft as a 2-axis stall and spin proof
entry level ultralight. The prototype weighed 210 lbs with Rotax 277.
The stall and maximum speeds just barely fall within the limits.
All turns are automatically coordinated with rudder and dihedral
effect. There are no spoilers or any other moving surfaces on the
wing. A rudder bar controls turns and a central mounted stick (which
does not move sideways) controls the elevator. Intentional slips and
skids are not possible, so cross wind landings are somewhat limited
as is normal with all other 2-axis ultralights. The cantilevered
wing uses the same stall resistant airfoil as the Ercoupe. It only
mushes when you pull the stick all the way back. This effect,
combined with the lack of alerons, make spins impossible. Everyone
who has flown the Pup remarks how easy and fun it is to fly.
Overall performance is excellent due to the light weight, lack of
struts or wires and the streamlined fuselage. Sky Pups have flown
with engines from 18 to 32 HP with the Rotax 277 being the largest
recommeded. The glide ratio and minimum sink rate is better than
most other ultralights. Cruise speed is 55 MPH with the Cuyuna 215
engine of only 20 HP. The taildragger is extremely docile to land
because of the wide gear, low CG, and very ample fin and rudder.
In the 12 years since it's introduction, over 2000 sets of plans
were sold. About 350 Sky Pups have been built and flown. Some are
nearing 1000 hours flight time. There have been no aerodynamic or
structural problems with the Sky Pup. In recent times there have been
a few more wood plans-built designs including the Mini-Max and Fisher
ultralights. Since they are 3-axis designs aimed at the 254 lb. limit,
they tend to cost a bit more, and take longer to build (from scratch).
Because of it's low cost and safe 2-axis design, a few new Sky Pups are
still being built, 12 years after it's introduction.
Scratch building any design, even the Sky Pup, is a major effort.
There are no premade components available. The plans, though very
detailed, are not full size. Construction is very much like a large
model airplane. Though experienced builders found it easy, some
novice builders said it was hard. Most reported building times
in the range of 450-600 man-hours. The time required varied from
13 weeks to eight years. The only special tools required are a table
saw and electric drill. There is no welding or fiberglass work.
A builders newsletter, the SKY PUP NEWS, was started by Sport Flight
in 1983. They published a total of 9 quarterly issues until I took
it over in 1985. A total of 29 issues were published over 8 years.
The newsletters are primarily of interest to builders as they contain
many useful building tips and ideas for modifications. A full set of
backissues is available for $25.00 or send $2.00 for an information
pack, sample newsletter and list of builders. Write to Daniel
Grunloh, P.O. Box 368, Loda, IL 60948. Phone 217-386-2213 evenings,
or send email to gru...@uiuc.edu.
The Sky Pup is a design from another time. I don't want to be
responsible for convincing someone to build a Pup when there are
newer designs available. I've been flying mine almost 10 years.
It's a safe, proven, low cost, low maintenance, easy to fly legal
Part103 ultralight with very good performance. As former newsletter
editor, I have always offered to answer questions from builders. The
company, Sport Flight Engineering Inc. is still very busy in engineering
consulting, structural analysis and prototype testing in sport aviation.
They no longer have time for telephone support so they do not promote
the design, though plans are still available.
-------------------------
--Dan (gru...@uiuc.edu)
--http://www.staff.uiuc.edu/~grunloh