The Super Gee II Discus Launch Glider
The Super Gee II is the latest of Dr. Mark Drela's DLG Discus Launch Glider designs. Extraordinarily light at 8 ounces target weight, it utilizes his excellent AG 4xx-xx series airfoils. The design incorporates several advanced concepts:
Airfoils that perform well at very low wing loadings and Reynolds numbers
Reflex built into airfoil for lower drag in both speed and cruise flaperon settings
RDS or Rotary Drive System (embeds the entire flaperon control mechanism to minimize drag)
1 oz. Kevlar balanced with higher density foam in the wing and tail cores (durable, lightweight construction)
Wing construction with carbon fiber weblets and spar caps (minimize spar weight yet have adequate strength and stiffness)
A lifting rudder that acts during a discus launch (counteracts yaw)
Wing mounted on pylons (minimal profile lowers drag)
The discus launch has spawned a revolution in hand launch gliders. A high performance DLG glider can attain heights at launch of over 50 meters. The Super Gee design is optimized for high performance and discus launch.
AG 4xx Airfoil Series
Since Dr. Drela created the AG 4xx airfoil series, many discus launch glider designs, especially those intended for high performance and competition, incorporate them. Excellent gliders utilizing these airfoils include:
SuperGee and SuperGee II
LightHawk
XP-3 / XP-4
Taboo
Encore
Epona
Raptr
Each of these are lightweight vacuum-bagged designs. In addition to DLG sailplanes with vacuum-bagged wings, some manufacturers are producing hollow molded wing designs with AG 4xx series airfoils, including:
Blaster
Fireworks III
Aspirin
Airfoil data files are at the Charles River RC club web site, in a section dedicated to Dr. Drela's airfoils.
You can make a Super Gee II yourself. Building one is a challenging and fulfilling experience. Besides the intrinsic reward of making a beautiful aircraft, using advanced materials and techniques, this glider flies wonderfully.
For those would like a lighter workload, you can purchase any of the completed parts. RC Builder makes all the components. Some individuals interested in the design make suitable pods.
We are continually working on a list of resources for building DLGs. You'll find materials for scratch building and makers of individual components on our Resources Page.
If you don't have aspirations to build, you can purchase a DLG with many of the attributes of the Super Gee II. RCBuilder offers the LightHawk DLG ©, a clone of the Super Gee II with modifications favoring commercial reproduction. All parts for the LightHawk are interchangeable substitutions for parts on the SG-II.
Other designs are available. The current commercial offerings of bagged wing, AG-airfoiled planes are excellent. See the Resources Page.
Bagged wing, competition-class discus launch gliders have strength, durability, and performance comparable to the Super Gee II. They are very suitable for fun/sport flying. The wing loading might be a little higher for some of these planes, but the difference in performance, if any, is much less than the typical difference in skills between pilots.
Hand launch gliders using hollow-molded methods are made in Europe and imported here. The hallmarks of molded planes is the fine quality finish and potential to very accurately reproduce the airfoil. Typically they are a little heavier, and little less durable.