The Schreder HP-15
sailplane
A glider or sailplane is a type of glider aircraft used in the leisure activity and sport of gliding (also called soaring). This unpowered aircraft can use naturally occurring currents of rising air in the atmosphere to gain altitude. Sailplan ...
prototype was designed by
Richard Schreder as a personal mount in which to challenge the 1969 U.S. National Soaring Championships.
[Said, Bob: ''1983 Sailplane Directory, Soaring Magazine'', page 20. Soaring Society of America, November 1983. USPS 499-920]
Design and development
With an extreme 33:1
aspect ratio and a relatively low empty weight, the HP-15 was expected to generate less
induced drag
In aerodynamics, lift-induced drag, induced drag, vortex drag, or sometimes drag due to lift, is an aerodynamic drag force that occurs whenever a moving object redirects the airflow coming at it. This drag force occurs in airplanes due to wings or ...
and therefore higher performance. The type achieved excellent
glide ratios in fast flight, but had disappointing climbing ability, due to extensive flow separation on the upper wing surfaces during slow flight and Schreder and the HP-15 finished in 65th place. After the Championships Schreder re-winged the fuselage to produce his next design, the
HP-16.
Operational history
In the April 2011 the sole HP-15 prototype, registered N5488, still existed and was privately registered in
Peoria, Illinois
Peoria ( ) is the county seat of Peoria County, Illinois, United States, and the largest city on the Illinois River. As of the United States Census, 2020, 2020 census, the city had a population of 113,150. It is the principal city of the Peoria ...
.
Specifications
References
Schreder Designs webpage
1960s United States sailplanes
Glider aircraft
Schreder aircraft
Aircraft first flown in 1969
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