From: svoboda@rtsg.mot.com (David Svoboda)
Subject: Re: National Sailplane Symposium - Trip report
Organization: Motorola Inc., Cellular Infrastructure Group
Date: Thu, 5 Nov 1992 00:46:27 GMT

Hey, first off, thanks for the GREAT trip report.  You must
take DARN good notes. :-)

In article <1992Nov3.181415.15932@nntpd.lkg.dec.com> fisher@kay.enet.dec.com (kay::fisher) writes:
|
|Next
|Terry Edmonds and Steve Metz on Full Size & R/C Sailplanes.

Terry is a REAL interesting guy.  He is from Iowa City, (I'm
orginally from Cedar Rapids (Iowa), near there, and I have been
seeing him and his straw hat at glider meets around there for as 
long as I can remember.

|Steve Neu - Electrics
|
|   Batteries get hot from inside out.

I wonder if anyone has given a thought to internal liquid cooling
for batteries.  It would be a natural for boats, but I could also
see an application for airplanes, for ground-based super-fastcharging.

|   The bottom line is there is this group working on telemetry devices
|   and a package that comes out about the size of a thermal sniffler.
|   Right now they are staying on a Ham band.  I would hope that they
|   can conclude their work and release something for sale on non ham
|   bands eventually - but there doesn't seem to be any real commitment
|   to a product much less any fuzzy goals.

I wonder if the no-code Tech license would cover this sort of
transmission?  Though I don't have one (yet), I have read the
requirements, and it's basically a no-brainer.

Any Hams want to comment?

|Next
|Maynard Hill - World Duration Record.
|
|   It turns out that Maynard Hill set another longer duration record
|   between when they booked him for this presentation now.  So I have
|   some data from both.  Basically he used the same plane for both and
|   for the first record he landed with a lot of fuel on board.

In 1982 or so the club that I was in successfully claimed the duration world
record (of the time) from Mr. Hill, after several years of development, with
a 25 hour flight.  Two weeks later, Mr. Hill reclaimed the title with a flight
an hour longer.  Aaaaahhhhhh!  :-)

|   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).

|   Anyway details on the plane.

|      Flight Pack
|         .982 pounds w 4 servos
|	 Rate Gyro
|	 uCPU w altimeter sensor
|	 1 D Cell 3.6 volt Lithium 13 amp hour battery
|	 Can run system with lights for 50 hours
|	 146 MHz Down link = postage stamp size
|	    Normally used to mount on wildlife (a Falcon)
|	    Hidden in the fin.
|	 Wing tip Rx on 449 MHz Direction finding Receiver

Hmm.  He used to use an automatic wing leveler which employed some sort
of electrostatic earth potential, with radioactive sensors at each
wingtip (he cannibalized smoke detectors).  No more?

|Next
|Professor Roland Stull - Meteorology for Model Sailplane Flyers
|
|   Then he showed several other graphs including one showing the top of the 
|   convective mixed layer altitude against time.  This shows that thermals
|   don't exist at night [something we know to not be universally true] and
|   that they start in early morning and grow rapidly thru noon.

Thermals, or something very much like them, certainly DO exist at night.  The
aforementioned duration record attempt ran into some problems when at about 2am
the airplane hit a boomer thermal, and even idle couldn't get it back.  It got
WAY up there, before full throttle and a light dive brought it out.

And although I have never done it, I know people who fly thermal sailplanes at
night.  It wouldn't be too much fun if there were no thermals.

Again, thanks for the great report.

			Dave Svoboda
Newsgroups: rec.models.rc