This is the part of the story where we introduce the ship, no less a character in its own right. Here is a photo of JOY, a Schempp-Hirth Nimbus-3DM.
JOY is our race vehicle. We’ll be flying JOY all over western Nevada during the competition.
JOY is a sailplane, and a big one, too: its wingspan is 24.5 meters, or a bit over 80 feet. Nearly all of JOY is carbon fiber composite, which is the main thing it has in common with a golf club. For all its size—and it’s hard to do a good job of characterizing how huge the thing really is—it weighs around 1,450 pounds empty. That’s really heavy for a glider, but lighter than a Smart car, and my own small car weighs a thousand pounds more.
Long, skinny wings are extremely efficient at slower speeds, which is why all sailplanes (and many drones, and all albatrosses) have them. Building gliders as big as JOY has disadvantages: big gliders are heavy, they’re usually less nimble, and those long wings are much easier to damage by bumping into things on the ground—trees, hangar doors, runway lights, family members, and so on. Most gliders have 15 meter (about 50′) wings, including my own, which you saw in plan-form above the last post. But there’s one sweet payoff for the trouble, and that is glide performance. Flying straight ahead at 55 knots or so, JOY barely sinks at all, losing a foot for roughly every sixty feet it travels. This ratio, 60:1, is called the “glide ratio”, and it’s extremely good.
Here is a triangle that is 60 times wider than it is tall:
Imagine JOY serenely coasting down the hypotenuse. Most gliders made these days are shy of 50:1, which frankly is not too bad either. Gliders are amazing vehicles.
I think JOY is a beautiful airplane. Mike doesn’t seem so certain—Schempp-Hirth adapted its design from a single-seat airplane and wound up sweeping the wings forward slightly, which is a feature of a few other well known designs. Opinions differ. I like it.
The image above is a still from this fine video, which midway through shows JOY in its natural habitat: the ridge-and-valley Appalachians. I’ll have more to say about those later. You’ll notice that JOY actually has a retractable engine, which may come in handy if we find ourselves low over remote desert places. The other plane in that video is an ASH 25; one of our competitors will be flying one of those at the Nationals.
“JOY”, by the way, is a contest identifier, a 1 to 3 character sequence that’s essentially the same as the numbers on the side of a race car. My own glider wears “I” (although it used to be “ZG”).
The interwebs claim that the -3DM means JOY is a “self-launch” version of the -3D. Is that what the retractable engine is for?
Yep, that’s right. The engine can also be deployed in flight if you find yourself out of lift and far from home.
And… we’re back! – Stepleton 34