99-inch wingspan
Sagitta 900 - RC sailplane. Quote: - "Sagitta, (pronounced Sag-ee-tah)
is a Latin word meaning arrow... The design is conventional in
appearance with careful attention paid to minimizing aerodynamic drag
and improving efficiency. Construction utilizes conventional model
materials and techniques, with structural design optimized to provide a
rugged airframe. This design can be easily duplicated by anyone who has a
flat bench and who has already built a simpler ship, such as the
Olympic II. Some additional time and effort in carving and sanding are
required to develop the smooth flowing contours of the Sagitta, but the
aesthetic and aerodynamic benefits are well worth the extra trouble...
Two major considerations influenced the design of the Sagitta: First, to
improve the flight performance of the Aquila and Aquila Grande; second,
to allow complete access to the radio equipment and ballast without
using any tools. In addition, we wanted to improve the spoiler hook up
system used on the Aquilas. These requirements led to the forward hatch
and hinged access panel which provide excellent fuselage access, and
simple spoiler hookup as well as wing retention. As a bonus, the tow hook
becomes readily accessible, simplifying adjustment of releasable
tow hooks. The fuselage design provides minimal frontal area and wetted
surface for decreased drag. The shoulder mounted wing position
eliminates two intersections, and the obtuse angle between the fuselage
sides, and wing lower surface makes wing fillets unnecessary. The slim
aft cross-section is possible through the use of stranded cable inside
tubing pushrods. The side and plan view outlines represent the minimum
envelope consistent with equipment space requirements and structural
requirements. Two ballast compartments are provided, which perm it the
flier to more than double the the model's weight. Full length poplar ply
sides with spruce longerons provide plenty of strength and rigidity. Of
course, the heart of any sailplane design is the wing. Sagitta utilizes a
relatively low aspect ratio to raise the Reynolds Number and to pack
900 square inches into a 100" span. This approach has been proven in
practice by the success of the Aquila and Oly II in Standard Class
competition. Wing planform is contant chord center panels with double
tapered tips. The center and tip panels are equal in span for better
turning characteristics due to improved structure and moments of
inertia. The sharply raked tips provide low drag with distinctive,
appearance. Polyhedral is used for quick turn response with
rudder/elevator control. The shallow center angle and increased tip
angles improve efficiency and give better response..."