NetNews Usenet Archive 1992 #26/NN_1992_26.iso/spool/rec/models/rc/4522

Text File | 1992-11-08 | 3.3 KB | 56 lines

Newsgroups: rec.models.rc
Path: sparky!uunet!panther!mothost!white!rtsg.mot.com!svoboda
From: [e-mail] (David Svoboda)
Subject: Re: National Sailplane Symposium - Trip report
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Date: Fri, 6 Nov 1992 20:20:50 GMT
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In article <[e-mail]> [e-mail] (Chris Kaiser) writes:
|In article <[e-mail]>, [e-mail] (David Svoboda) writes:
|> |   He currently holds the worlds records for altitude = 26,990 feet.
|> |   33.3 hours duration (the subject of this talk).
|> |   150 MPH speed record.  I don't know what class this is or if was
|> |   an old sailplane record that is no longer standing?
|>
|> I don't think it can be right.  The current record is well over 250mph, with
|> a glider (that's faster than the powered record--model props don't work too well
|> at those sort of speeds).
|
|Wasn't that the record set in Austria, where they thermalled/mountain-soared a
|F3B styled brick (called a "Dassel" or something?) to several thousand feet and
|then put it into a vertical dive before levelling out through the speed course...
|I think the reg's have been changed since then, and it is now required to fly a
|closed course, or do a return run within a time limit, or something like that.
|Perhaps this guy holds the record under the current rules.

Y'know, I'm not too sure of the current record holder's methods, except that
it was with an engineless aircraft.  I can tell you one thing, though; I was
peripherally involved in some speed record attempts in the `70s and, what these
guys used were thin metal-reinforced airplanes with huge servos mounted in
rigid foam, and OPS engines with homemade props.  In order to nullify any
help from the wind, they record attempts had to fly through the traps twice,
once in each direction.  The usual method was to vertically climb until just
about out of sight, scream back down vertically, gradually pull back to level
and fly through the entry trap.  (They mounted the servos in rigid foam because
they kept breaking servo mounting flanges with the flight loads; in foam all
they had to do was be sure to correct with rudder, as the elevator loading
moved the servos around in the foam.)  The aircraft then SCREAMED downfield
through the other trap, then back to vertical, almost out of sight, roll over
in a split-S, vertical dive, big pullout, and scream back through the other
way.  From what the guys said, the engines were used pretty much only for the
climb and start of dive, and the props were just big flat sticks out there for
the actual speed run.  They had thought about an adjustable-pitch prop, but
couldn't figure out a way to make one stay together at that sort of revs.

Anyway, my point is that the rules back then required a double-pass, so I bet
the glider did a double pass.  Maybe the rules don't say you have to do the
other pass *immediately*, so they did one pass, worked their way back up the
slope lift, and did another pass the other way.

        Dave Svoboda, Palatine, IL