Whenever a discussion of optimum flight strategy in head winds and sink comes up, I go back to an excellent web site that graphically ties all of this to drag polars:
http://home.att.net/~jdburch/polar.htm In a head wind, you do not want to fly at the max L/D, as illustrated nicely on this web site. Dick ================ >I can add some credibility to these numbers. > >Flying at max L/D is great when looking for thermals in relatively still >air. > >However, where flying at best L/D is really, really important is when you >are trying to return to the field from downwind in a stiff breeze, or a >howling hurricane. > >The problem is that flying at max L/D isn't optimal. Some higher speed is. >To comprehend this, it is useful to imagine trying to get back in a breeze >which is exactly your best L/D speed, It isn't difficult to understand that >you will have zero ground speed and never get home. So best L/D is some >unknown speed that is higher than max L/D. What that speed is, is totally >dependent on the specific wind speed, and is one of the most difficult >things to learn. At the F3J selection trials a couple of years ago I was >most impressed by the ability of the top pilots ability to come back home >from way, way downwind in a wind that was really pushing them back. If I had >a really good feeling for that I would be able to stay in lift much longer >than I currently dare. > >Anker -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Dr. Richard C. Williamson Phone: 781-981-7857 Room C-317 FAX: 781-981-0122 Lincoln Laboratory Email: [EMAIL PROTECTED] Massachusetts Institute of Technology 244 Wood Street Lexington, MA 02420-9108 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED]
