The Cheechako, which is named after
what a newcomer or 'tenderfoot' was referred to in Northern Canada and Alaska, is an
entry-level rocket boost free-flight glider. The name fits perfectly with the monthly
"For the Tenderfoot" series that ran in the AMA's American Aircraft Modeler
for many years. Cheechako uses what was at the time the second-smallest Estes rocket
for power. The thrust and engine run time were minimal, and there was a 2-second delay
time before the ejection charge was fired to eject the heavy motor casing out of the
back of the mounting tube. I had a Falcon rocket boost glider as a kid and loved it since
the configuration allowed me to combine my other other indulgence: model airplanes (hence,
the name of this website).
January 2014 update.
For the Tenderfoot: Cheechako
by Larry Renger
Here's a Delta-Winged glider for rocket power.
Build from these full-sized plans, make a launcher from next month's article, then fly
it straight up.
Remove plan from magazine and protect it
with wax paper during construction. Note trailing edge is pre-shaped trailing edge stock,
available in most hobby shops.
Hand glide the plane with used motor or equivalent
weight to check trim. If glide is good, the rocketing climb will be good.
Cheechako is a "boost-glider" - a model airplane which
uses a high thrust rocket motor to achieve altitude, then glides smoothly for a landing.
This model will use 1/2A6-2 size Estes, Centuri or equivalent model rocket motor. Bigger
engines will provide a more spectacular climb, but are not recommended for the Tenderfoot.
A "Cheechako" is a tenderfoot in Canada and the northern fringes of the United States.
This model was specifically designed for this magazine's series of easy to build and
fly models. It is not an "off-the-shelf" design which sort of fits the slot. The design
goals which were set up before pencil hit paper are: (a) no critical shaping or carving;
(b) built-in alignment and trim; (c) warp-proof construction; (d) no moving parts or
critical tolerances; (e) good performance. In other words, try to design an AMA Delta
Dart for rocket power, only more so.
Cheechako meets all these goals and even manages to look sharp as an added feature.
The use of a flat construction, delta planform wing with preshaped trailing edge stock
is the secret to the success of this model. I went through (and I mean THROUGH) several
prototypes to get the trim to the "off the building board" stage. If your model is built
exactly to the plans and balanced where indicated, it should fly too.
The basic construction sequence, shown on the plans, is self-explanatory, so we will
just hit a few details here to help make your model perfect.
Cut each stick slightly oversize, then trim down to fit its space smoothly. Fit and
trim till each part is right; don't hesitate to throw out a part if it is cut too small.
Use white glue or Titebond - but sparingly! Smear a thin film of glue on each part
where it is joined, then slip the parts together. Sand the basic frame flat, using 220
grit paper and a sanding block. (A small plastic box works well for a block.)
The proper tissue technique is as follows: (1) Apply two coats of dope to all parts
of the model where the tissue will touch it. Sand very lightly after each coat with 320
or 400 grit paper. (2) Cut the tissue oversize, using "Jap" tissue only! (Your hobby
dealer will carry this product.) The grain runs along the wingspan. The paper will tear
more easily along the grain to test which way it goes. (3) Lay the tissue on the model
and very lightly tack it down with raw thinner. You can make it go around corners easier
on the edges by dampening that part before sticking it down. To final trim the tissue,
use a new razor blade - no knife blade comes close to that sharp edge. Shrink the tissue
with water spray or gently brush the water on.
It says it on the plans, but it can't be overemphasized: GLUE THE RUDDERS ON STRAIGHT!!
The pod alignment should also be accurate. The pin holes through the tissue, shown on
the plans, allow the glue to make a good wood-to-wood bond. The foil protector strip
can be ordinary household aluminum foil stuck down with rubber cement.
Flight should be pretty good "off the board," but here is what to do to fine-tune
your model. First, check the balance - it should be exactly 4 1/4" from the nose point
of the wing. Fly the model with a 1/2A6-2 engine to start with. It should go up straight
with perhaps a slight roll. If the model loops seriously, trim the trailing edge narrower
in the center. (You got some with a steeper than normal angle carved in.) For a slight
arch-over on the way up, tweak just a little turn into one rudder to make the model roll
on its upward travel.
The glide should be smooth with a wide turn. Warp the rudders to add or remove turn.
Move the CG back and forth to achieve a smooth glide just on the edge of the stall. The
model may tend to stall more near the ground due to turbulence. Don't readjust to cure
this, it is normal.
Cheechako Rocket-Powered Glider Plans
<click for larger version>
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.
Try my Scale Calculator for
Model Airplane Plans.
January 19, 2014 Update:
Über rocket boost glider builder David Wagner sent me this note and photos of
his excellent Cheechako. David has established a unique "signature" finishing scheme
on his models that consists of a solid red and/or white base with aluminum foil in a
decorative pater in the rocket motor exhaust area.
Photos of the Cheechako rocket glider I built from plans on your site. It weighs 5.75
grams as shown here. It was tremendously nose heavy as built from plans, so had to change
to the small Estes 'T' size motors, which are about half the size of regular motors.
Also had to make a much shorter nose cone, hollowed out, and move the whole nacelle back
a half inch. Also added dihedral. With this configuration, it glides very nicely and
is quite stable. Like any delta, I suspect it will be sensitive during transition, and
to even light breeze. Too windy to fly Saturday, but will try again next Saturday.
Estes Falcon Rocket Boost Glider by David
See all of David's rocket boost gliders:
Posted January 27, 2013