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The TheMe of this month’s column is Rudder-Elevator-Spoiler
(RES)-class gliders.
I’ll give a brief explanation of the class, an update on the
rekitting of the Sagitta 900, and details of Rich Burnoski’s RES
offerings and his new company. I’ll also include my impressions
of the Two-meter Chrysalis and an introduction to Mark Drela’s
Allegro-Lite RES design.
In ReS class the controls are limited to rudder, elevator, and
spoilers. This competition class is intended to let relatively simple
and inexpensive gliders compete on a level playing field.
Computer radios are not needed, so the initial investment can
be three to four times lower for an RES glider.
In general, RES gliders are easier and faster to build than the
flaperon-equipped full-house gliders. They are also easier to
Mike Garton, 506 NE 6th St., Ankeny IA 50021; E-mail: [email protected]
RADIO CONTROL SOARING
The classic lines of the Sagitta 900 in flight. Short kits and
fiberglass fuselages are available for this glider.
Rich Burnoski (R) of Chicago, Illinois shows off his new RES
design, Chicago Style. Bill Wingstedt is on the left.
Spoiler detail on the Chicago Style. The spoiler is a thin piece of
conforming composite, which is taped in place.
Paul Wiese and his original design Poly-Mantis for RES. The
small bulge on the tailboom behind the wing is a hand grip.
thermal than the models with flaperons, because turns are
automatically coordinated.
The Sagitta 900 is an excellent choice for RES. Designed by Lee
Renaud, it is a built-up model with a 100-inch wingspan and a
conventional tail.
The Sagitta was a breakthrough, partly because of its
computer-designed semisymmetrical airfoil. The Eppler 205 can
generate high lift for launching or thermaling, and it has good
penetration and a high lift-to-drag ratio.
At the time of this writing (mid-October), Roy Simpson of
Dream Catcher Hobbies has “short kits” for the Sagitta 900.
These kits include plans, photo-illustrated instructions, laser-cut
wing ribs, wing-rod receiver blocks, and the spruce trapezoid
leading-edge pieces.
The special preshaped spruce pieces deterred scratch-builders
during the last few years. It is nice to hear that you can buy them.
Dream Catcher also has fiberglass Sagitta 900 fuselages and
short kits for several other polyhedral airplanes. Roy plans to
upgrade many of the short kits to “full kits,” as time permits.
The Aquila XL is another good RES kit from Dream Catcher. I
should have mine completed before you read this. I will write
more about it soon.
The Aquila XL is a 150-inch-span variant of the Aquila, which
had a short production run before 1980. Thus, it is Nostalgialegal.
Read more about it on The Dream Catcher Web page.
Rich Burnoski of Chicago, Illinois has started a glider business.
One airplane he will sell is his RES airplane—the Chicago Style.
This model is a modern RES design with a 120-inch wingspan,
and it sports a modified SD7037 airfoil. The fuselage is
fiberglass, with a slip-on nose cone. The wing is vacuum-bagged
carbon and glass over foam. Weight is 72-74 ounces.
If you know Rich, you know he likes to launch hard and go
fast. The Chicago Style has the strength to zoom-launch, and it
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has the glide ratio to reach distant thermals. Rich placed fifth in
RES at the 2000 AMA Nationals with the prototype.
The Chicago Style’s spoiler design is neat (see photo). The
blade was made by vacuum-bagging carbon and fiberglass
between two pieces of Mylar™ in a wing-core bed; it is only 15-
thousandths of an inch thick. This allows it to lay flat on top of
the existing wing skin without disturbing the airflow too much.
Only a small hole has to be cut in the top wing skin for the
linkage. Very little stress concentration is created. A servo is put
in from the bottom side of the wing to direct-drive each blade.
This setup is fast, easy, and strong.
Spoilers are notorious for opening up on launch, because of
suction above the wing. The short direct linkage on the Chicago
Style will prevent that from happening.
Besides selling some of his designs, Rich plans to be a “stocking
dealer” of molded composite airplanes and of accessories for them.
He has invested a huge amount of money in his inventory.
By having airplanes in stock, Rich should be able to deliver
them to the customers within a couple days. Other moldedairplane
vendors typically take six to 10 weeks to deliver after an
order is placed.
Rich calls his new company Chicago Sky1; his Web site
address and contact information are at the end of the column.
Paul Wiese’s RES airplane could have fit well in last month’s
section on Mantis variants.
The bulge on the tailboom behind the wing is a hand grip.
Holding a large airplane by a small-diameter tailboom is not easy
in the wind.
When winch-launching, it is especially critical that polyhedral
models are released with the fuselage in the plane of the line. A
crooked release can cause the airplane to dart off to the side at
high speed and low altitude.
This problem is most severe on airplanes with large amounts
of polyhedral. Narrow tip chords aggravate the situation.
DJ Aerotech’s Two-Meter Chrysalis is
another relatively new RES kit. It has
proprietary airfoils and a 26- to 27-
ounce weight.
I have seen several Chrysalises fly, and
I have flown one. The handling is good,
and so is the penetration, which surprised
me; the Hand-Launched Glider (HLG)
Chrysalis does not penetrate well.
I did not get a feel for the dead-airfloating
capability; there was too much lift
when I was flying.
Don Stackhouse has put a great deal of
engineering and innovation into the
Chrysalis’s structure. An experienced
builder can assemble the wing in one
evening. The leading edge is a dowel, so it
requires no shaping. The shear webs are
precut and prealigned on tabbed wood.
The parts are provided to build a V-tail
or a conventional tail. I recommend the
conventional tail for beginners; V-tails are
more difficult to set up perfectly.
Some intermediate pilots modify their
Two-Meter kits to use a bolt-on wing.
Another common modification is the
addition of a vertical plywood blade across
the wing center joint.
The Chrysalis Two-Meter was touted as a
replacement for the Carl Goldberg Gentle
Lady. It is nice, but I do not think it will
replace the Gentle Lady, which looks prettier
in the hobby store and costs a third as much.
Guess which one the newcomers will choose?
I would be happy if a new guy showed
up at the field with either model.
