This rocket boost
glider called the Dyna-Soar was powered by
American Telasco's version of the
Jetex 50 engine. Jetex rocket
engines were quite popular with model airplane, boat, and car builders through the
early 1970s, at which point the fuel supplies began to disappear. Most Internet
sources posit that
Imperial Chemicals Industries (ICI) ceased making the fuel pellets
due to a combination of liability and regulation issues. ICI, based in Scotland,
manufactured the
Jetex fuel pellets* from a measured blend of guanidine nitrate,
2,4-dinitroresorcinol, potassium nitrate (aka saltpeter), iron oxide, kaolin, and
asbestos. Today, obtaining the required chemicals, or even doing an Internet search
for them (as I just did), will probably get you a big red flag in the Department
of Homeland Security's database. There are probably a couple agents on the way to
my house as I write this.
* See the
Jetex Propulsion Lab for a incredible bit of information on the
motors and the fuel.
Rocket (Jetex) Powered Dyna-Soar
Designed and tested by Paul Del Gatto
Dyna-Soar, the manned space glider, is an incredible flying machine. Compared
with this Mach 25 terror, even the famous X-15 is a toy. Boosted aloft by a Martin
Titan, it will combine the high speed of the ballistic missile with controlled,
accurate flight of manned aircraft.
Dyna-Soar's pilot will shorten or lengthen its range by thousands of miles, changing
course to reach a landing site. He can choose fields as far apart as Point Barrow,
Alaska and San Diego. Able to operate subsonic, transonic, supersonic and hypersonic,
Dyna-Soar will be capable of operating like a large, fast aircraft when approaching
an airport.
Later developments of Dyna-Soar for weapons-system and escape missions and to
circle the moon will take various combinations of Saturn boost stages.
U.S. Air Force's rocket boost glider.
Boeing is prime contractor for system and the piloted glider.
Surprisingly, a model Dyna-Soar is easier to make than many a free-flight design.
Deltas like Dyna-Soar long ago demonstrated their performance and stability capabilities.
The Jetex Pay-Loader "150" rocket motor with its augmenter tube provides plenty
of push and the craft presents no adjustments problems.
Your Dyna-Soar, built as a unit, is practically complete before lifting it from
the workbench. Only the fins, part of the elevons and the landing skid remain to
be added.
Since weight and balance are important, the craft should be covered with lightweight
Silkspan tissue and colored dopes should. be used sparingly. Follow the hardnesses
of balsa specified.
Wing: Pin down 1/8" x 5/8" hard-balsa tapered leading edges
and wing trailing edge pieces, followed by medium 1/8" x 3/8" balsa center-section
pieces. Fit and double-cement in position 1/8" x 3/8" medium ribs and diagonal pieces.
Assemble built-up portions of the "elevons" using hard 1/16" x 1/4" trailing
edge pieces and medium 1/16" x 1/8" and 1/8" -sq cross pieces where required. Aft
sheet-balsa pieces (elevens) are added later.
It is important that this procedure be followed in making the elevons ... for
each elevon pin down and cement to wing trailing edge the four main cross pieces;
attach the elevon trailing edges flush with the top of the cross pieces, then the
diagonals. Elevon cross sections (on side view) are obtained later by sanding the
bottoms of the elevons cross pieces and diagonals to match the 1/16" thick elevon
trailing edges.
Fuselage: Cut formers from medium sheet balsa, noting thicknesses.
Erect formers F-5, F-5B, F-6, F-7 and F-8 on center section pieces, then slip augmenter
tube into position. Tube is rolled to shape from .005" aluminum 2-5/8" wide plus
allowance for an overlapping seam.
After erecting formers F-1 and F-2, cement in motor mount. This is assembled
from 3/32" medium balsa base (full body width) and 1/16" thick plywood overlay 3/4"
wide (to which metal motor-mounting bracket is screwed).
Dyna Soar will be boosted into space by modified Titan III missile
as seen above.
Before sheet covering the fuselage make sure you understand the hatch construction.
Fuselage sides are 1/16" medium balsa sheet, extending forward to 1/8" sheet fill-in
cabin nose piece. Sides are feathered together where they meet at the nose. Fill
in where necessary with balsa scraps.
Forward portion of removable hatch is carved from soft balsa block 5/8" thick.
Hatch extends to F-4. To complete hatch, insert formers F-3 and F-4 and plank with
soft 1/16" sheet. When thoroughly dry, model is removed from work surface.
Final Assembly: Add 1/16" x 3/4" soft-balsa sheet elevon pieces,
then sand smooth entire model, taking care that elevons taper from the bottom to
a thin edge at their trailing edge, as per the side view. Cut fins and rudders,
sand smooth, cement in place. Note they are offset slightly relative to centerline.
Round off leading edge pieces.
Cut air-intake holes in forward fuselage. This air flow is required for augmenter
tube to serve its purpose - stepping up thrust. Cover the holes with fine wire screening.
Shape 1/4" thick landing skid from two laminations of 1/8" sheet balsa, cement
securely in position.
Painting and finishing: Give wing framework a coat of clear
dope wherever covering will touch. For sheet-balsa fins, rudders and elevons plasticize
dope with four drops of castor oil per ounce of dope. This minimizes warping due
to dope shrinkage.
Cover wing top and bottom with lightweight Silkspan; use one piece for the bottom
and two for the top. Run grain spanwise. The fuselage is not paper-covered. For
overall doping of completed covering, use mixture of 1/3 thinner and 2/3 dope. Give
covering three coats, allowing each to dry, and each time apply a coat of dope to
the fuselage. After each of the first two fuselage coats, sand sheetwood skin with
fine paper.
Dyna Soar launched into the wild blue yonder.
Here is
American Telasco payloader rocket power plant.
Color scheme is dark blue fuselage and silver wings. Mix colored dope with thinner
2/3 and 1/3 as before, apply two coats. Lettering and insignia trim are from hobby
shop decals.
Flying: Test glide model, launching it by the landing skid.
If tail heavy, add clay ballast to nose. If nose heavy bend up elevons slightly.
For best performance model should be trimmed with elevons raised 5° to 10°.
Make these initial tests over soft grass and avoid windy weather. Aim the model
at a ground spot about 50' ahead in these hand glides.
When flying with power point nose up slightly, launch with the same force as
for hand gliding.
Further adjustments are carried out by bending individual elevons and/or the
trim tab (note bend line) of the left fin. For example, bending up the left elevon
(looking down on the craft from the rear) will cause a right hand turn and vice
versa. Never bend an elevon down.
If more turn control is desired, or if a smoother, coordinated turn-and-bank
is needed, bend the fin trim-tab in conjunction with elevon adjustment. Thus, bending
the tab toward the center line while bending up the left elevon, coordinates both
controls for a right turn. If Dyna-Soar turns too tightly, use opposite adjustment.
Be sure to select plenty of flying space because your Dyna-Soar will live up
to its name. It climbs like a homesick angel and probably will come down out of
sight unless adjusted to circle.
Dyna-Soar Materials:
(Balsa unless otherwise specified)
One 1/16" x 2" x 36" (medium) for fuselage sides and formers; (1) 1/16" x 3"
x 18" (soft) for fuselage top and elevons; (1) 3/32" x 3" x 18" (medium) for fin,
rudder arid engine platform; (1) 1/8" x 2" x 18" (medium) for fuselage formers,
gussets and wing fill-ins; (1) 1/8" x 5/8" x 36" (hard) for tapered wing leading
edge; (1) 1/8" x 1/2" x 18" (medium) for wing trailing edge; (2) 1/8" x 3/8" x 36"
(medium) for wing ribs and diagonals; (1) 1/8" x 1/4" x 18" (hard) for elevon trailing
edge; (1) 1/16" x 1/8" x 36" (medium) for elevon ribs and diagonals.
Also: 1/16" plywood engine mount; aluminum foil liner; fine wire mesh screen
air inlet; 1/32" diameter wire; light weight Silkspan covering; Pay-Loader "150"
engine; clear and colored dopes; cement; decal; .005 aluminum for augmenter tube;
clay ballast.
Full size drawings for Jetex-powered model are on Hobby Helpers' Group Plan #762A
(85¢).
Rocket (Jetex) Powered Dyna-Soar Assembly Drawing
Rocket (Jetex) Powered Dyna-Soar Plans
Notice:
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.
|