That is an excellent article by Mike Valentine. Explained a couple of things for me in simple terms that I could cope with. Thanks for bringing it to my attention.
regards John Ashford 07 3822 4264 0409679867 _____ From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Terry Neumann Sent: Friday, 12 September 2008 10:30 AM To: Discussion of issues relating to Soaring in Australia. Subject: Re: [Aus-soaring] 60 AOB turn james dutschke wrote: 60 degrees when low and slow?? in a 60 degree AOB turn your pulling 2g, and as a result your stall speed goes up by 41%.... No argument required. The initial actions after a cable break are attain safe speed near ground, before pulling airbrakes, initiating turns etc etc. given that safe speed near ground is 1.5Vs, that gives you a 9% margain for error, and that is in dead smooth air. Lets chuck in some wind sheer (i seem to recall this happeneing in the extreme low levels of the atmosphere) not to mention thermals etc etc. Some good points made here James. This thread has developed some worrying aspects in the last couple of days. Perhaps all the more because some are talking about aerotow failures - some about winch launching breaks. The scenarios and options for the pilots are usually somewhat different. It's perhaps a good time to read again (or for the first time) an article written by the late Mike Valentine on the perils of "turnbackitis" written for the AUF, but which has frequent and useful references both to and for gliding - especially for winch launching. As always, Mike made some very good points and raised some aspects of this whole matter which may be news to many. It certainly was for me. HYPERLINK "http://www.auf.asn.au/magazine/turnback.html"http://www.auf.asn.au/magazine /turnback.html What has really worried me at times as I look on in wonder (and occasionally sheer horror), are the limited options available for some self launching gliders as they slowly utilize the curvature of the earth to make the most of a very marginal "performance". "He wouldn't want the music to stop now ...." or similar sentiments are usually the only interruptions to a thoughtful spectator gallery's silence when one of these captivating events is played out in less than ideal circumstances. Regards, Terry No virus found in this incoming message. Checked by AVG. Version: 7.5.526 / Virus Database: 270.6.21/1667 - Release Date: 11/09/2008 6:55 PM No virus found in this outgoing message. Checked by AVG. Version: 7.5.526 / Virus Database: 270.6.21/1669 - Release Date: 12/09/2008 2:18 PM
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