ACE Awards - Superior Quality

Superior Quality
Sponsored by AOC and Composites One

This award is presented to the entry that is manufactured by open, single sided molding and best demonstrates exceptional fit, finish, and quality.

Entry: SparrowHawk Sailplane

Submitted by: Windward Performance, LLC; Bend, Oregon

PRODUCT DESCRIPTION
The SparrowHawk is a prepreg carbon fiber sailplane that weighs only 155 LBS. The structure is strong and responsive, combining the performance of much larger sailplanes with handling and climbing ability that until now was not thought possible. The use of composites in sailplanes has allowed the sleek aircraft to achieve outstanding performance with their highly refined shapes and smooth surfaces for low drag. The 270 F oven cured prepreg construction has a higher strength to weight ratio. The structure is more dimensionally stable, so its smooth contours stay smoother over time. The high temperature capability of the composite materials allows the completed aircraft to be a color other than white, which is required for sailplanes constructed by room temperature systems. The SparrowHawk’s composite parts are made in carbon epoxy female molds for an accurate and relatively low cost tooling method for the aircraft that fits its production rate. The parts are hand layup of an epoxy resin system, carbon fabric, and unidirectional tape supplied by TORAY. The T700S carbon fabric is woven in a unique woven unidirectional format. The 12K tows are flattened and woven in a plain weave that combines the advantages of unidirectional and cloth in a fabric with a very useful 190 g / m2 area weight. T700G unidirectional tape is used for the caps in the spars. Flight surfaces are cored with Divinycell HT-50 foam from DIAB. This combination does not require the use of film adhesives, thereby saving weight as well as money and time in the layup process. Secondary bonding of composites is done with Loctite Hysol 9394 epoxy adhesives. The composite parts are finished with automotive two part urethane primers and polyurethane paints.