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Combat 12.7

veröffentlicht um 15.03.2014, 02:52 von Michael Husmann   [ aktualisiert: 15.03.2014, 02:53 ]
 Auszug aus Paris Williams Gedanken über den neuen voll Carbon Combat 12.7 (Quelle ozreport.com  (ozreport.com/forum/viewtopic.php?t=36667 abgerufen am 15.03.2014))

..."The day-three days before Day One of the Pre-Worlds. The place-the famous (and infamous) El Peñon near Valle de Bravo, Mexico. After several hours of racing around the local hills and valleys on the new Combat 12.7, delightfully winding my way up through the fierce, snaky bullet-thermals for which this region is so well renowned, I found myself pleasantly surprised by the ease with which I found myself gently touching down into the main LZ in spite of the turbulent, switchy conditions. At that moment, a single word erupted from my lips-"Finally!"

Reflections on the New Combat 12.7

Finally, the moment I've been waiting my entire flying career for. Finally, someone has made a glider designed for lighter pilots that was more nimble and pilot-friendly than any competition glider I had ever flown while clearly matching the performance of the big gliders. As a lighter pilot (I weigh between 67-70 kg, or between 145 and 155 lb.), it has always been a struggle coming up with a workable setup that has allowed me to keep up with the "big boys."

It has generally been held as a truism in our sport that the smaller gliders simply don't keep up with the bigger gliders. As a light pilot, if you really want to be able to match the performance of the bigger gliders, you better just get used to flying gliders that are a little too big and stiff for you and carrying around a lot of ballast so that you can keep up with the heavier pilots on glide.

There's been a lot of speculation as to the reasons for this. Perhaps it's because larger gliders have more favorable Reynold's numbers (which has to do with the density and viscosity of the air relative to a given wing); or because they have higher L/D since they generate more lift while not generating a comparable amount of additional drag (for example, the parasitic drag of the control frame and the pilot doesn't increase when going from a smaller glider to a larger glider, whereas the overall amount of lift does); or perhaps it's because manufacturers simply put more effort into the bigger wings since there are more larger pilots on the market. But for whatever reason, this is a problem us lighter pilots have always had to contend with.

But now, after my first flight on this little glider, I suspected that this historical deficiency had finally been broken. And as the PreWorlds began, and I found myself flying head-to-head with the other gliders, my suspicion was quickly validated. There was simply no doubt about it. I found myself gliding right alongside the best of the bigger gliders without having to wear any ballast, and most surprising of all was the climb.

I had the good fortune to be flying with some of the very same pilot/glider combinations I had just flown with at the Australian Nationals in Forbes, and there was no doubt about it that in spite of now being on a smaller glider (I had been on the 13.2 in Forbes), my climb had significantly improved, and I'm pretty certain that I could even fly more slowly, go figure. With some of the same pilots who had been able to sit on top of me at Forbes, I found that our roles had reversed, and I found myself now sitting on top of them with surprising ease. And the real beauty was having all of this performance without the need to carry an ounce of ballast (which is always a bit of a drag, especially when landing at these altitudes-7,000 to 10,000 feet MSL), and without the need to destroy my shoulders trying to battle a stiff glider in wild conditions. I just couldn't get over how much performance I was experiencing right alongside such sweet handling. Finally!

By talking with other pilots over the years, I've learned that Combats have developed a reputation for being not so easy to land. And in my opinion, there's a good reason that this reputation had developed. I remember being surprised by how challenging it was to land the very early Combats well, especially those manufactured up until around 2001 or 2002. Actually, I still own a 2002 Combat as my personal fly-at-home glider, and there's no doubt about it, it's a bit tricky to really "stick" a light-wind landing well on the thing. But in the past few years, this has dramatically changed, only it seems that the word hasn't gotten out.

(Bild Quelle: aeros.com.ua)
I remember several years ago when first flying the new higher-aspect, tailed Combats, how pleasantly surprised I was by how easily and crisply they flare, and how wide and forgiving the flare window is. And I found that the 12.7 takes this ease of landing to a whole new level.

The landing conditions here at Valle de Bravo are some of the most difficult I've ever encountered, with small sloping fields loaded with obstacles, very switchy winds, very thin high-altitude air, and bullet-thermals that love to pounce just as you're turning onto final. And with the exception of one incident in which a well-timed pouncing thermal caused me to overshoot my field into the lee-side of a large brick wall on a windy day, I managed to pull-off a no-step landing every time.

I found that two factors contributed to this: (1) the stall speed is surprisingly slow on this glider, allowing me to really slow down before the flare; and (2) the nose rotates very easily in a flare, allowing for a clean, crisp flare without either the tendency for the glider to climb or the nose to drop even if you're a little early or a little late in the flare timing. I suspect the high aspect ratio and the hang point being well in front of the control frame apex contribute to these very user-friendly landing characteristics. (On a side note, I found it interesting that I had a tendency to overshoot my landings a few times, and in retrospect, I think that what was going on for me was that because this glider handles so much like an intermediate glider, I was unconsciously anticipating that it would have a short ground effect like an intermediate glider. Of course, it's not an intermediate glider but a very high performing competition glider with a correspondingly long ground effect, and this threw me off a few times. Or perhaps I can just blame the fact that I've become a little spoiled flying the wide open flatlands for too many years.)

This is the first time I've flown a fully-carbon glider (full leading edges and cross bars, that is) since flying the king-posted Predator many years ago, and I have to say it was a real joy to experience the reduced wingtip-inertia in the air (significantly lighter, more responsive handling) and the reduced weight on the ground (this glider weighs just over 30kg).

When first looking at these sleek, oval/conical leading edges, I had to wonder why it's taken glider manufacturers so long to finally take real advantage of the potential that carbon fiber offers. Having a much higher strength to weight ratio and being much more malleable than aluminum, it's about time that we move beyond simple round tubes. These oval/conical shaped tubes allow maximum stiffness along the horizontal axis, which maintains maximal trailing edge tension, while allowing maximal flexibility along the vertical axis, which maximizes handling. They also gradually decrease in diameter from the nose to the tip, which minimizes overall wing inertia. What an elegant design!

I imagine it won't be long before the other manufacturers follow suit. (I found it interesting that a number of the non-Aeros pilots have begun adding plastic and carbon tips onto their gliders which are strikingly similar to the Combat's Horner tips, and some are even using Combat tails(!)-Signs of Combat envy?

Dies ist nur ein Auszug. Paris gesamte Reflektionen über den neuen Combat, die Bedingungen und den Wettbewerb findest du hier: ozreport.com/forum/viewtopic.php?t=36667