Xref: utzoo rec.aviation:28618 rec.birds:2833 Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!wuarchive!uunet!zephyr.ens.tek.com!tektronix!sequent!jli!andy From: andy@jli.UUCP (Andy Johnson-Laird) Newsgroups: rec.aviation,rec.birds Subject: Re: The most competent soaring pilots are... Message-ID: <933@jli.UUCP> Date: 12 Sep 90 21:00:28 GMT References: <1990Sep11.125658@unify.com> Reply-To: andy@jli.UUCP (Andy Johnson-Laird) Organization: Johnson-Laird Inc. Lines: 47 In article <1990Sep11.125658@unify.com> raveling@unify.com (Paul Raveling) writes: > Sunday, while soaring near Minden, I had another of those > rare encounters with a red-tailed hawk -- with the hawk joining > up in the thermal I'd found. I still find it damned exhilarating > and take it as a compliment from the expert -- the hawk, that is. Yeah! I was soaring just east of Mount Hood about two weeks ago and hit strong thermal at about 1500 agl. I shutdown the engine and retracted it (sorry purists, but it's a selflaunching sailplane) and went on about the business of gaining alttitude. When I got to about 3,700 agl I suddenly noticed I was not alone. There was what we Brits call, a "bloody great bird" in the thermal with me. I would estimate a wing span of at least 6 feet (though it's difficult to get scale at times like this). I remember noting the underside of the bird had lots of white dappling. I also noticed that this BGB (BG bird) was holding....wait for it.... a large *fish* in it's talons. It's talons were positioned "fore and aft" holding the fish with its head towards the front so as to minimize the drag. (Parasitic or Piscine Drag being important to avoid). As Paul says, it's a privilege to soar with birds like this. Typically they only let you stay in the same thermal for one or two turns while they size you up and then decide they really would be rather somewhere else in the sky. THen they flip inverted, extend their talons as dive brakes (I presume) and roll out of the thermal inverted. Has anyone ever seen birds carrying their prey this high off the ground? I found myself wondering what would happen if the bird became alarmed by the 800 lb fibreglass monster and dropped the fish? a) What is the terminal velocity of a fish dropped from 3,700 agl? b) What would the headlines in "The People" read (Earth invaded by spacefish?) As a final thought, how do these marvelous birds find thermals? What do they use as a vario? I can't believe *they* look for sailplanes as a means of finding a thermal! :-) Andy Andy Johnson-Laird ===+=== DG-400 N400YE Johnson-Laird Inc. \|/ ..tektronix!sequent!jli!andy --o-- 850 NW Summit Ave. / \ Portland OR 97210 -------=================( o )=================------ Tel: (503) 274-0784 \ / Fax: (503) 274-0512 O Voicemail 274-0510 Self-launching sailplane pilots do it by themselves.