My dad, brother, girlfriend and I walked into an aircraft hangar in Bend, Oregon. This was the home of Windward-Performance LLC, maker of the SparrowHawk glider. It is owned by Greg Cole, formerly of Lancair. Anyway, we saw a painted yellow glider, and a carbon fiber hull sitting on a floor stand. I glanced around and noticed molding and tooling for the wings, fuselage, and various other parts. Greg graciously let us take turns sitting in one of the finished gliders and gave us a lengthy shop tour.
As we were finishing looking around the shop, my dad handed me a cheque and told me to give it to Greg. As I did, I glanced at the amount. Then it registered. My dad had just put a down payment on a new glider. It is scheduled for a march 2004 delivery. I am now part owner of a glider!
Greg Cole has been sitting on the SparrowHawk project for the past ten years. His work at Lancair, a kit airplane company, has provided him with quite a bit of experience in ultralight design and carbon-fiber construction. The SparrowHark was concieved of after Greg realised that the entry costs for soaring were usually well above the reach of most pilots. Not everyone has 200,000 for a new open class glider, or 50,000 for a decent used glider. The SparrowHawk was thus concieved of as a low-cost world-class sailplane. The world-class is a sailplane class for small, affordable gliders.
When it came time to make design decisions, carbon fiber was selected as the construction material. It has the distinct advantages of being light and easy to build. It is also easely reparable and very, very strong.
Windward-Performance was thus formed, and the design was finalised. The design and building philosophy is completely different from previous airplanes. Greg made a mockup of the glider parts, from which he made molds. He then started making production gliders. He did limited testing of models, and thoroughly analysed his design. But, when the first glider came out of the molds and was painted, it was serial number 001. There were no beta, experimental, or test airplanes. This was a huge gamble, but it payed off, as no serious problems have been found by owner number 1.
Owner number 1 has in fact broken 3 world records, and flown the plane so hard, Greg Cole has almost wet himself. The plane is safe and stable. Greg is making plane number 7 as of May 2003, and has orders for about 20 planes so far. This glider is one of the first of the newest generation of wholly carbon-fiber airplanes. Eta is the other new carbon fibre based glider.
The SparrowHawk represents the newest class of gliders. Pre-impregnated carbon-fiber is used for most of the aircraft. This material comes in rolls of fiber cloth with resin already embedded, unlike normal carbon fiber cloth that functions like fiberglass. The prepreg fiber cloth is formed in a mold, then vacuum sealed to press the cloth into the mold, and baked at 300 degrees F. This process allows less resin to be used on the fiber, creating a strong, but lighter and more flexable structure.
Each plane is built-to order. While the airplanes are all of the same design, many custom options can be added. My dad is currently working with Greg to add conduit through the wings for lipstick cameras. There are several options that are offered and usually installed. The entire package can be had for about 40,000 dollars, including the trailer, GPS, and BRS. Some common options are listed:
- Ballistic Recovery System (BRS)- An optional 40 foot parasail can be installed. This parachute is fired out of the airplane via a rocket and is attached near the center of gravity. It allows a damaged glider to float to the ground instead of crashing and killing the pilot.
- Oxygen System-The FAA required that Oxygen be used above 14000 feet, or above 12500 feet if at that altitude for longer then 30 minutes. The O2 system comes with an 11 cubic foot Kevlar bottle and automatically discharges in sync with ones breathing. This limited-flow system releases oxygen only when the user inhales, not all the time. This design allows the bottle to last quite a bit longer then other systems.
- Global Positioning System-A GPS system with a map that scrolls with your location can be installed. This is basically a GPS reciever with a PalmTop-like interface that displays navigational information, airport info and terrain.
- Trailer-Windward Performance will build a custom trailer for the glider with internal padding and cradles for each wing and the fuselage.
- Paint-A two part polyurethane paint is used. It can be whatever color you want. The painter will even do custom designs and detailing. Most gliders were painted white to protect the fiberglass components from heat. Since this protection is no longer neccassary, the gliders can be any color. I am looking for that disgusting lime-green some road signs are now painted. This is for visibility, as it is better to be seen then unseen in any vehicle.
- Wing Span: 36.1 feet
- Length: 20.6 feet
- Height: 4.5 feet
- Maximum Weight: 415 pounds
- Takeoff Weight: 400 pounds
- Empty Weight: 155 pounds
- Wing Loading: 5-6 pounds/foot2
- Wing Area: 70 ft2
- Stall Speed: 32 knots
- Maximum Speed: 123 knots
- G limits:5.48 positive gravities, 4.0 negative gravities
- glide ratio (L/D): 36 at 50 knots, 24 at 75 knots
- Production Volume: 21 Hulls by fall of 2004
Sources: Fundamentals of Sailplane Design, http://www.windward-performance.com/.
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