visitor Kenneth E. wrote to say that he is working to build a complete collection
of the Tenderfoot models that were published in American Aircraft modeler.
The Tenderfoot series was an attempt to provide motivation to young newcomers
to the hobby. They were a mix of freeflight rubber, gliders, and 1/4A &
1/2A control line designs that built simply and cheaply.
requested reprints of the following three models:
basic hand-launched glider can be patterned after almost any real aircraft.
These fly great.
By David Thornburg
Heave ho! Trim model for left turn in glide if you launch right-handed.
Then model makes a curling climb and arrives at maximum altitude with
wings level and at glide speed.
Setting dihedral joints is merely a matter of having enough small dope
Models use same wings but Bonanza's tail is slightly longer. Color with
LIKE TO BUILD a flying model that's simple, quick, and fairly realistic?
Here it is! Choose either of two well-known aircraft-the Mustang or the
Beech Bonanza-and build the plane directly from the full-size plans. Or,
better yet, build both at once for a real ball! A single sheet of 1/4 x
3 x 36" will build three fuselages, and two pieces of 1/16 x 3 x 36" will
easily build all of the flying surfaces for two to three models. By building
two or more planes at once, airplanes can be turned out in less time than
by building them singly, especially if they are the same or nearly the same
in design. This is a trick the experts use in building their stables of
high-performance contest jobs.
In performance as well as appearance,
both planes are a cut above most of the chuck gliders that can be bought
in the stores. The Mustang flew out of sight in a big, lazy thermal the
third time I had it out-good thing I got pictures first!
are a number of ways to build from full-size plans. The easiest is to cut
out the magazine pages, tape them together, and use carbon paper to trace
the parts onto balsa. However, once this is done the plan is as good as
lost, and the book is pretty well ruined. Most modelers like to keep their
books intact, both for reference and for nostalgia. My own collection dates
back into the early 1950's, and I often turn to it for design ideas and
performance tips. Aerodynamic theory doesn't change much, so books don't
really get out of date.
It's best, then, to avoid mutilating the
I book. Instead, either trace the part outlines directly onto thin paper,
using carbon paper, or run the page through a Xerox machine available at
most libraries or schools. This last method is not against the law as long
as the plans are for personal use only. Be sure to ask for legal size, and
the whole plan should come out in a single printing.
To trace the
parts from the copy of the plan, use carbon paper or the pinprick method
- aligning the plan over the wood and punching shallow pinholes every 1/4"
or so all around the outlines of the parts. Notice the grain direction of
all of the parts, because it's very important. Learning to use wood grains
to their best advantage for strength and warp-resistance is one of a modeler's
most valuable skills.
Use the softest wood available for the fuselage.
If no really soft 1/4" is in the balsa rack, drop down to 3/16" and pick
a piece of medium softness. The harder the wood, the heavier it will be,
and neither model can stand a great deal of extra weight if it is to fly
The only difficult cuts on the fuselage are the wing and stabilizer
slots. They must be marked accurately. A modeler's knife with a triangular
blade helps in the cutting. The cut can be made with a single-edge razor,
but the slots must go through the fuselage exactly on the perpendicular.
Otherwise either the wing or the stabilizer will have a high side and a
low side. These perpendicular cuts are much easier to make with a long-handled
knife than with a razor blade. When using a razor, prop it against a scrap
piece of 1/4" balsa (one with a square edge) to guide it into the wood straight.
Cut the wing and tail out of mediumweight, straight-grained balsa.
Don't be backward about asking the hobby dealer to help in selecting this
piece of wood. Tell him what it's for, and ask if he has C-grain balsa.
C-grain indicates the way the balsa was sawed out of the log; it is particularly
good for strong, light sheet surfaces.
What about airfoils? Most
models this size have some sort of curve to their wing cross-section, whether
it's a scientifically plotted shape or simply a warp made by spraying the
top side of the wing with water and pinning it to a flat surface until dry.
The plans show no airfoils, just a flat plate, and that's what the
planes pictured have. I tried airfoiling the wings, but it didn't increase.
the performance much. However, later models were built with 3/16" wood for
the wings and a conventional airfoil sanded into them. (Both the wood and
the instructions in Jetco Thermic B hand-launch kits are ideal for this
purpose.) This increases the performance of both gliders amazingly, and
makes them almost contest quality. Try it on your second or third model
Flying is simple. Add nose weight until the plane
balances about 1" back from the front of the wing. A coin glued onto the
side of the fuselage as far forward as possible makes a fine weight. Throw
the plane gently, aiming it at the ground about 30 ft. in front of you,
and observe the turn. If you are right-handed, the plane should turn left;
opposite for lefties.
Now tightly grip the fuselage, under
the wing, between thumb and third finger, putting the tips of the first
and second fingers behind the wing trailing edge and snug against both sides
of the fuselage. Throw the plane sidearm, so that it starts out in a right
bank and circles. If you have the proper amount of left turn in the glide,.
it should "s-out" into a left turn at the very top of the throw.
Experiment with the direction of throw in relation to the wind to find the
best altitude. Generally it will be just slightly to the left of the wind,
but the choice of direction depends on the individual. Good flying!
Bonanza and Mustang Plans <click for larger
The AMA Plans Service offers a full-size
version of many of the plans show here at a very reasonable cost. They will scale the plans any size for you. It is always
best to buy printed plans because my scanner versions often have distortions that can cause parts to fit poorly. Purchasing
plans also help to support the operation of the Academy of Model
Aeronautics - the #1 advocate for model aviation throughout the world. If the AMA no longer has this plan on file, I
will be glad to send you my higher resolution version.