Larry, a larger wing span indeed would help, provided that the airfoil is appropriate. It is not necessarily true, that the larger wing span produces more drag, on the contrary.
Drag from the wing is created in two ways: the first is the drag that is associated with the specific lift you create at specific speeds. That correlation can be found for every airfoil in form of the CL/CD (Coefficient of Lift vs. Coefficient of Drag) diagrams. This is the diagram were the plotted graph typically looks like a crooked C. The other part of the drag is created by the fact that the wing is limited in span, so there is a flow of air from the bottom of the wing towards the top of the wing going around the edge of the wing. This is what creates the vortices at the end of the wing, and that is why some poeple put winglets on the wing end - to prevent this cross flow of air. This darg is by the way called the induced drag. The drag created by this flow is a multiple of the drag created by the lift. If you want to build a low drag aircraft, you try to build with maximum wing span and a maximum lenght to depth ratio. This way you can minimize induced drag. This is done with high performance gliders. A good example is the new "eta" aircraft, information about which can be found in www.leichtbau.de/eta . This glider has a wingspan of more than 100 feet, and it's best glide ratio is somewhere close to 70. (Imagine this, you glide 70 miles with loosing only 1 mile altitude). And yes, these gliders can go fast (140 mph or faster!!). One last thing: Gliders certified in Germany need to fulfill +7/-4 g load requirement, if it is approved for acrobatics it is +11/-7g. Remember, as a glider pilot you love to fly right into turbulent air, a.k.a. thermals. On a good day it can be gut wrenching, but exhilirating. If you catch a thermal that takes you up with about 1,500 fpm it's rough flying, but looking at the altimeter as it turns so quickly and all that without any engine, that's what's great about glider flying. Anyway, bottom line is: If you can increase your wingspan with paying the penalty of excessive more weight, and if you are sure that the the spars can carry the additional loads it certainly will help at higher altitude. Wolfgang -----Original Message----- From: krnet-bounces+wdecker=cox....@mylist.net [mailto:krnet-bounces+wdecker=cox....@mylist.net]On Behalf Of larry severson Sent: Thursday, June 24, 2004 10:34 AM To: KRnet Subject: RE: KR> High Alt > >Let's see if I understand... If I want better climb on a hot day or at high >altitudes, what is it that I need? OH, I know, longer wings. Darn, I think I >just flunked. OH OH, now I know, it's POWER. Gee, I guess that those powered gliders are just a figment of my imagination and lying marketeers. Longer wings do increase drag, but they also increase lift, reduce stall speed, and make possible flight with a less powerful engine. As they said at school, with enough power one can make a brick fly, but if power is restricted one had better give the vehicle enough wing area to lift the brick. Larry Severson Fountain Valley, CA 92708 (714) 968-9852 lar...@socal.rr.com _______________________________________ to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net please see other KRnet info at http://www.krnet.org/info.html
