HDTenEightyP/NetNews huggingface dataset:
From: gerry@macadam.mpce.mq.edu.au (Gerry Myerson)
Subject: Re: Parallel axiom.
Organization: ceNTRe for Number Theory Research
Date: Wed, 26 Aug 92 00:28:30 GMT

In article <1992Aug25.170135.504@csc.canterbury.ac.nz>, wft@math.canterbury.ac.nz (Bill Taylor) writes:

[...]

> I am enquiring for other logically equivalent forms of the parallel axiom. 

[...]

I think that the existence of a pair of non-congruent similar triangles is 
logically equivalent to the parallel axiom.

>            Bill Taylor              wft@math.canterbury.ac.nz

Gerry Myerson
From: marc@autodesk.com (Marc Ramsey)
Newsgroups: sci.aeronautics
Subject: Re: Beer commercial
Date: 26 Aug 92 01:08:58 GMT
Reply-To: marc@autodesk.com
Organization: Autodesk, Inc.

>I saw a  beer commercial on TV this weekend and it featured what appeared to
>be one of the cranked arrow configured F-16's. I could be wrong though...

It is a Saab Draken, a Swedish supersonic fighter of early 60s vintage.
There is at least one privately owned example in the US, and it has appeared
in a couple of movies...
From: rsmith@montana.ee.byu.edu (Robert Smith)
Newsgroups: sci.aeronautics
Subject: Re: Auto engines for aeroplanes
Date: 28 Aug 92 16:09:23 GMT
Organization: BYU


In article <STEVEBU.92Aug27094120@bullwinkle.atc.ll.mit.edu> stevebu@bullwinkle.atc.ll.mit.edu (Steve Bussolari x5956 g41) writes:

   There are many aircraft that have flown and are flying with
   water-cooled piston engines.  Take a look at an illustrated history of
   aviation.  Today, supplemental type certificates exist for installing
   automobile V-6 engines in light aircraft.  These engines go on the
   airplane with no substantial modifications.  There are efforts
   underway to certify new aircraft with liquid-cooled automobile engines
   (as in the Porche-powered Mooney).  A significant advantage to liquid
              ^^^^^^^^^^^^^^^^^^^^^

Actually, the Porsche aircraft engine is based on the _air-cooled_
flat six engine that has powered the 911 for many years.  More precise
cooling control is maintained by using an internal fan and electronic
control rather than slipstream air.  Engine control is much more
automated than most aircraft engines - mixture and cooling are
maintained by a computer.  All the pilot has to do is select the
desired power setting.

A big difference between aircraft and auto engines in general is the
speed of operation.  Most aircraft engines don't operate at much more
than 2000 rpm.  This allows the propeller to be directly coupled to
the drive shaft.  Small powerhouse auto engines develop power more in
the 4 to 6000 rpm range.  Using this type of engine requires the
addition of a reduction gear, which adds complexity and reduces
reliability (very important in an aircraft!:-).  However, more
reliable reduction gears have been and are being developed recently to
take advantage of auto-type engine technology to get the power from a
smaller displacement, lighter weight, and more fuel efficient engine.

Bob Smith
From: cshotton@oac.hsc.uth.tmc.edu (Chuck Shotton)
Newsgroups: sci.aeronautics
Subject: Re: Birds getting sucked.
Date: 1 Sep 1992 16:23:02 GMT
Followup-To: sci.aeronautics,sci.environment
Organization: Academic Computing

In article <Btv8oD.KrE@news.larc.nasa.gov>, mark@cmb00.larc.nasa.gov (Mark
Flanagan) wrote:
> 
> 
> >
> >That explains the development of the 'chicken gun', a device that shoots
> >(dead, thawed) chicken onto plane windshields.

I think the official term for the gun was "Rooster Booster."
Xref: sparky sci.aeronautics:1899 sci.environment:10936
From: utidjian@remarque.berkeley.edu (David M.V. Utidjian)
Newsgroups: sci.aeronautics,sci.environment
Subject: Birds getting sucked.
Date: 31 Aug 1992 06:35:06 GMT
Organization: Processed People for a Processed America
Distribution: world
NNTP-Posting-Host: remarque.berkeley.edu
Keywords: airports, FOD, noise, gulls
Originator: utidjian@remarque.berkeley.edu

I seem to remember hearing, some years ago, that there is a problem
at some airports with birds, especially seagulls getting sucked into
commercial and military jet air intakes.  I have heard that this is a
common problem.

Is there any "common" solution??

-poisoning the birds?
-shooting the birds?
-scarecrows?
-sound cannons?
-making a sound that the birds find unpleasant?
-an odor the birds find unpleasant?
-an odor or sound the birds find attractive away from the airport?
-a decoy that looks like a predator?

I have heard mention of all of the above techniques...
What is most successful for coastal airports?
Are there some that I have missed?

Any suggestions especially with referrences, however vague, would
be greatly appreciated.

David Utidjian
utidjian@remarque.berkeley.edu

	"Don't sweat the technique!"
				Anon.
From: Charles.K.Scott@dartmouth.edu (Charles K. Scott)
Newsgroups: sci.aeronautics
Subject: Re: Auto engines for aeroplanes
Date: 31 Aug 92 17:28:15 GMT
 <u5@byu.edu>
Organization: Dartmouth College, Hanover, NH

This is a subject near and dear to my heart because, in all likelyhood,
it's what will be powering my homebuilt.  It doesn't seem to matter
much at this point what block is used since a reduction box is
available for almost anything these days.  The reduction boxes run from
cast aluminum polished belt reduction mechanisms to straight spur gear
reductions to planetary reduction boxes.  The best of them are cast
aluminum ready to bolt to the engine block.  The big problem is weight.
 Using a cast iron block can make for a very heavy engine.  Using the
various aluminum blocks is possible but the cost skyrockets.  Probably
the most important aspect is to not use the engine without tearing it
down and checking it out.  Mine will be built by a friend who builds
race engines for a living.  He is insisting, at the moment, that a cast
iron block should be used.  He was willing to discuss using one of his
purpose built aluminum blocks but I pointed out that I wasn't going
racing and had no need for a block that would remain stiff at 8,000
rpm.  By that time we had agreed that we would optimise the engine for
about 4,000 rpm.  So he agreed that the racing aluminum block wasn't
necessary but so far has remained firm on the cast iron.  I don't
really want to argue with him because he has so much experience.  He
really does know his engines.  He's so experienced GM sent him a dozen
raw aluminum castings to make engines from to see what kind of
horsepower he could get from them.  But again, I'm not racing.  I don't
mind spending the money for things like a forged crank and connecting
rods, but a *LOT* of weight could be saved by using a street aluminum
block.

Figuring the propellor could take a long time too.  Details like how
fast it should be turning, the length, pitch etc all sort of depend on
how much horsepower is available at the tap...which of course is
dependant on what's spinning it.

Great subject for discourse, an enormous variety of possible answers.

Corky Scott
From: augustho@aludra.usc.edu (August Horvath)
Newsgroups: sci.aeronautics
Subject: Re: SAAB Draaken
Date: 25 Aug 1992 19:18:21 -0700
Organization: University of Southern California, Los Angeles, CA
NNTP-Posting-Host: aludra.usc.edu

I forgot to mention:  the same day I saw the Draakens at Chino, there was also
a Lansen on the flight line.  This one had an N-number, which I jotted down.
Haven't seen a SAAB at Chino since.

August Horvath <augustho@aludra.usc.edu>
From: bass@convex.com (Brad F. Bass)
Newsgroups: sci.aeronautics
Subject: Re: Auto engines for aeroplanes
Date: 27 Aug 92 16:31:28 GMT
Organization: Engineering, CONVEX Computer Corp., Richardson, Tx., USA
X-Disclaimer: This message was written by a user at CONVEX Computer
              Corp. The opinions expressed are those of the user and
              not necessarily those of CONVEX.

In <17irplINNuh@darkstar.UCSC.EDU> zap@ucscb.UCSC.EDU (ZaP!) writes:


>Eric Paulsen  
>was discussing the relative merits of auto and aircraft, liquid and air cooled
>engines.

and

> zap@ucscb discusses some successes with liquid-cooled engines  --
> notably the Rolls Royce Merlin...
>However, the liquid cooled engine still has a trick that the aircooled
>cannot easily mimic:  It is far easier to streamline.

Quite true, and there's yet another trick.  It turns out that it's very
unhealthy to throttle back an air-cooled engine quickly from cruise power.
The reason is that it cools too rapidly in a uneven manner, causing
cracked cylinders and warped valves.  It's called "shock cooling".  You
must very gradually retard the throttle to prevent this from happening.
Descents from cruise altitude must be planned well in advance and Air
Traffic Control reminded so that you don't get a "slam-dunk" approach.

Liquid-cooled engines are immune to this malady.  In fact, you can now
buy a liquid-cooled, 350 HP, TSIOL-550 engine from Continental Motors
as a replacement for your air-cooled motor.  RAM Aircraft Corporation
in Waco, Texas will do the install for you.  Incidentally, because
the cowlings are more streamlined than the orginal ones, RAM boasts
a 20-knot cruise speed improvement.
--
Brad Bass		It is a well-known phenomenon that computer programs,
bass@convex.com		left to themselves, will cease to work. This is known
Convex Computer Corp.	as "Bit Rot".  Programs NOT left to themselves also
Richardson, Texas	cease to work.  This is known as "enhancement".
Newsgroups: sci.aeronautics
From: doshay@ursa.arc.nasa.gov (David Doshay)
Subject: Re: ducted fan design
Organization: NASA-Ames Biocomputation Center
Distribution: sci.aeronautics
Date: Fri, 28 Aug 1992 00:46:54 GMT

The Kitplanes that I got in the mailbox yesterday (October issue) just
started a multi-part series on ducted fans. The first installment did
not answer your questions, but who knows what is to come.

David		doshay@soma.arc.nasa.gov

The thought police insist I tell you:
my thoughts, not NASA's
Newsgroups: sci.aeronautics
From: tostan@bert.lerc.nasa.gov (Stan Mohler)
Subject: supersonic B-52's??
Organization: NASA Lewis Research Center [Cleveland, Ohio]
Distribution: usa
Date: Fri, 4 Sep 1992 15:59:48 GMT

Someone who doesn't know much about aviation recently told me that
B-52's used to fly supersonic over Columbus, OH in the 1960's.  
I know that the B-52 is a subsonic bomber.  But is it possible
that it could go supersonic in a dive, and is it possible that
this was done over Columbus in the '60's?  Thanks.

-- 

-----------------------------------------------------------------------------
Stan Mohler			|     phone: 216-826-6629
NASA Lewis Research Center     	|    
Cleveland, Ohio  44135         	|     email: tostan@bert.lerc.nasa.gov 
-----------------------------------------------------------------------------

Newsgroups: sci.aeronautics,sci.environment
From: zeke@wdl50.wdl.loral.com (Solly Ezekiel)
Subject: Re: Birds getting sucked.
Organization: Loral Western Development Labs
Date: Tue, 1 Sep 1992 20:36:41 GMT

In article <1992Sep1.021643.7454@panix.com> reynolds@panix.com (Brian Reynolds) writes:

>This reminds me of a story told to me by a shop teacher while I was a

Well, while we're telling humorous stories...

This one was told to me by a fellow who worked at Pratt, and is apparently a
true story.  One night, a janitor cleaning out a test cell there inadvertently
started the engine that happened to be in it.  The janitor was on the upstream
end of the test cell, and got sucked towards the intake.  Luckily, a net had
been placed in front of the intake, which prevented him from actually entering
the engine.  However, his body obstructed the intake sufficiently to cause
the intake compressor to stall.  High-pressure air came squirting out each
end of the engine, blowing our friend down the tunnel, which cleared the
intake obstruction.  The intake compressor recovered, and air began to flow
through the engine once again, dragging our friend back towards the intake.
He went through several of these cycles before someone was able to shut the
engine down.  Apparently he suffered some broken bones, but came through
it in pretty good shape considering what could have happened.

  +--------------------------+---------------+---------------------------+
  | "Asps!!  Very dangerous. |               | My opinions are not those |
  |     ...You go first."    |  Sol Ezekiel  |      of my employer,      |
  |          -- Sallah       |               |    Space Systems/Loral    |
  +--------------------------+---------------+---------------------------+
From: johng@informix.com (John Galloway)
Newsgroups: sci.aeronautics
Subject: Fluid dynaics sim (50mph air) on a Quadra 700, is it possible?
Date: 26 Aug 92 16:47:17 GMT
Distribution: ca
Organization: Galloway Research
Originator: johng@godzilla

(previously posted to comp.simulation)
I have been tinkering around with various edge treatments for the
windshield on my motorcycle in an attempt to reduce/move/affect
the turblance layer that comes off the trailing/top edge (right into
my helmeted head (helmet skirts and/or ear plugs are the existing
answer).

I would like to get more scientific about this and am wondering if
my mostly idle but up all day Quadra 700 A/UX system could be useful
doing fluid dynamics simulations of proposed configurations.

I would appreciate some guesses as to the complexity of such calculations
(navier-stokes or something like that?) needed to carry out such simulations
(even assuming the sw is available and not toooo expensive).

Just wild guessing I get:

3.00            width (ft.)
3.00            length
3.00            height

46,656.00       cubic inches
8.00            points/inch
23,887,872.00   points/data set

3.00            floats per point in dataset (3D pressure vector?)
4.00            bytes per float
15.00           flops/point/itteration (vector to components and back and?)
1,025.16        MFlops/itteration
50	        itterations (gives ?? 1/4 second at 50 mph?)
500.00          MFLOPS of sys
30              % of run MFLOPing
341.72          hours for run
14.24           days for run

0.01            MB/sec (reading/writing compressed data for run)
273.38          MB/raw data set
2.73            compression ratio to achive:
100.00          MB/compress data

Which says that even on a 500MFLOP machine I would need 1/2 month, with 1/8
inch grid spacing, on a 5(?)MFLOP Quadra => no way.  Is this problem really
not this bad, or have I guessed close enough to be clear that its totally not
feasable to get any meaningfull results (for design assistance) within a few
days on a Quadra.  The data set size is actually viable, I could make good
use of a new 1.5GB disk, and 68MB of memory, but its the crunchyness, or
lack of it, that kills the idea.  right?  thanks.
        -jrg


-- 
internet    jrg@galloway.sj.ca.us  John R. Galloway, Jr  795 Beaver Creek Way
applelink   D3413                  CEO...receptionist    San Jose, CA   95133
                                   Galloway Research     (408) 259-2490
Newsgroups: sci.aeronautics
Subject: F16A Huds & Simulation
From: misdcc@otago.ac.nz (Chris Hinch)
Date: 27 Aug 92 12:53:35 +1300
Organization: Dunedin City Council, Dunedin, NZ

F16's, HUD's and Simulation

As part of a research project into flight simulation techniques
I am developing a replica cockpit of a F16A (Block 15). 

One of the areas that is 'interesting' is the HUD.  Diagrams and
photos of early block (inc. Block 15) aircraft show a small HUD 
with a prominent video camera.  However, a photo supplied by GD 
of a F16A (no block number supplied) shows a larger HUD without 
the camera, and various controls replaced by four 'thumb' wheels, 
two either side of the panel.  It appears smaller than the 
Marconi (?) HUD found in the later block aircraft (20+?).  Can 
anyone id this HUD variant?  Was it ever installed on Block 15
aircraft?

Secondly, can anyone explain (in simple terms please :-)) how 
the actual HUD works?  My understanding is that an image 
of the HUD symbology is created either on a CRT or by a 
raster scanning laser, which is then focused, collimated etc
and projected/reflected onto a holographic mirror (reflecting
only the wavelength of the laser/CRT phosphors) mounted
in front of the pilot.

Questions.  Does the image seen by the pilot appear ON the
holographic mirror, just beyond it, or at infinity? What are
the optics involved, and can anyone suggest means of simulating
it (eg, if the actual HUD is laser based, could a CRT be used
instead - obviously, the image would be a lot dimmer, as CRT
emitted light is all over the spectrum, and only a very small
part of it would be reflected by the holographic mirror).
Again, if it is laser based, is the laser projected directly
onto the holographic mirror, or onto a screen which is then
reflected by the mirror?

Any assistance that anyone can/is allowed to give would be 
greatly appreciated.

Thanks in advance

Chris Hinch
misdcc@otago.ac.nz

[insert usual disclaimer here and tear along dotted line] 

-- 
Chris Hinch                <misdcc@otago.ac.nz>
PC Administrator
Dunedin City Council                      DUNEDIN. It's all right here!
Dunedin, New Zealand                                        ~~~~~
From: ccoprmd@prism.gatech.EDU (Matthew DeLuca)
Newsgroups: sci.aeronautics
Subject: Re: F22 Air Force purchases.
Date: 3 Sep 92 13:01:11 GMT
Organization: The Dorsai Grey Captains

In article <117@newave.mn.org> john@newave.mn.org (John A. Weeks III) writes:

>BTW, the nickname Lightning II is not an official name--it was given to the 
>plane by Lockheed, but the USAF does not have to use this name.

Considering what I heard the Air Force was planning to call the plane, 
Lightning II would be an improvement.  They're wanting to call the thing
the 'Superstar'.

(I have this mental image of a guy with one silver glove flying the 
plane...ack.)
-- 
Matthew DeLuca                      "I'd hire the Dorsai, if I knew their 
Georgia Institute of Technology      P.O. box."
Office of Information Technology                - Zebediah Carter, 
Internet: ccoprmd@prism.gatech.edu              _The Number of the Beast_
From: gcr8829@aw2.fsl.ca.boeing.com (Gustav C. Rettke)
Newsgroups: sci.aeronautics
Subject: Re: Beer commercial
Date: 25 Aug 92 19:51:45 GMT
Organization: fsl

From article <BtIB45.63G@ais.org>, by draper@ais.org (Patrick Draper):
> I saw a  beer commercial on TV this weekend and it featured what appeared to
> be one of the cranked arrow configured F-16's. I could be wrong though...
> 
I saw it and it wasn't an F-16.   It was a Swedish SAAB Drakken.  Drakken came
out in the late 50's and enjoyed a fairly long production run until replaced
in the mid-late 60's by the Viggen.

They were exported in Europe somewhat.  The one on the commercial must have
been a surplused one ala the Vampire's and other European marks that are
showing up at air shows here in the states.


There's an interesting history of the Drakken in Bill Gunston's book
"Early Supersonic Fighters of the West".

Hoe this info helps.

A Plane Buff
From: lzago@eso.org
Newsgroups: sci.aeronautics
Subject: Public domain computational fluid dynamic programs
Date: 31 Aug 92 16:56:07 GMT
Article-I.D.: pj1.9208311556.AA10622


Are there any computational fluid dynamic programs in the
public domain, in particular available on the InterNet ??
I need a "simple" K-eps" program for a mixed/free convection problem
but it does not need to be very sophisticate with pre/post-
processors etc.
 
Plase answer by e-mail.   Thanks in advance.

Lorenzo Zago                         Internet: lzago@eso.org
ESO - European Southern Observatory  Earn: lzago@dgaeso51 - Span: eso::lzago
Karl Schwarzschild Str. 2            Uucp: lzago@eso.uucp or eso!lzago
D-8046 Garching, Germany             Tel:+49 89 320 06 0   
                                     Fax:+49 89 320 23 62
From: jtien@venice.eng.uci.edu (Joe Tien)
Subject: need info on CFD benchmark programs
Newsgroups: sci.aeronautics
Reply-To: jtien@venice.eng.uci.edu (Joe Tien)
Organization: University of California, Irvine
Date: 3 Sep 92 23:02:13 GMT


Hello everyone,

Sorry to bring in something serious into a light-hearted discussion (that's what
I've been reading so far), but someone suggested that I try this group.

I'm using some Computational Fluid Dynamics programs as benchmarks for my cache
design, but have no idea what these programs do. So, what I'm trying to find out
is: what equations do they implement and what should the inputs and outputs to
the program be.

The ones I have are: unriems.xx.c, crale.xx.c, line.xx.c, and nav.70xx.c.

Please email me at jtien@balboa.eng.uci.edu

Thanks much,

Joe Tien
Newsgroups: sci.aeronautics
From: gopal@cirrus.com (Gopal Ramachandran)
Subject: Re: Auto engines for aeroplanes...
Organization: Cirrus Logic Inc.
Date: Wed, 2 Sep 1992 20:50:18 GMT

Doug Meyer, who now owns a Kawasaki motorcycle dealership in Dublin CA,
used to be race car mechanic for the Shadow CanAm team back in the early
70s. He moved to California in the late 70s and worked for an outfit
called Thunder engines, I believe. They installed modified CanAm Chevy
engines in Rockwell Twin Commanders. The engines would produce almost
1000hp in a race car. They detuned them considerably for the aircraft
application. I believe the flight tests were quite successful but they
ran out of money before certification could be completed.
	Call Doug at 510-829-4466 and he''ll probably be glad to
describe his experience with this mod. Tell him Gopal sent you and I'm
about to hit 100K miles on my '87 Kawasaki 750R :-).

Gopal
-- 

Gopal Ramachandran <gopal@cirrus.com>
UUCP:  uunet!cirrus.com!gopal
Cirrus Logic Inc, Fremont CA  PH: (510)-226-2138 FAX: (510)-226-2160
Xref: sparky sci.aeronautics:1896 rec.aviation:14442
From: gt8303a@prism.gatech.EDU (The Great and Mighty Confused)
Newsgroups: sci.aeronautics,sci.environment
Subject: Re: Birds getting sucked.
Date: 1 Sep 92 14:42:50 GMT
Followup-To: sci.aeronautics
Organization: Georgia Institute of Technology

Just to remind our readers of the 'chicken gun''s more illustrous name...

the "rooster booster" hurls frozen chickens at aircraft canopies.  I saw a show
several years ago about it.  Can't remember the show, though.

Andy Entrekin
Organization: Freshman, Mechanical Engineering, Carnegie Mellon, Pittsburgh, PA
Newsgroups: sci.aeronautics
Date: Thu, 27 Aug 1992 01:41:37 -0400 
From: Eric Eimal Paulsen <ep1a+@andrew.cmu.edu>
Subject: Re: Auto engines for aeroplanes

I assume you're talking about high-performance racing engines. Nothing
else would come even close. I suppose it's feasible, just not very
practical, for the following reasons:The engineering concerns of auto
engines and airplane (IC) engines are quite different, obviously.
Cooling needs for instance. Auto's are predominantly watercooled,
whereas planes ( as far as I know) are air-cooled. Each type of cooling
is most advantageous in the environment where is used( which is why it
is used there). The two types of engines have followed two different
engineering development paths, diverging as they develop due to
differents conditions.They're simply apples and oranges. Putting an
engine designed for ground use in the air negates the advantage of air
cooling, increasing the complexity and weight of the engine. You'd be
forgoing all the advances made in the engine you're replaceing with one
not even designed for that use. On the other hand, it might be
interesting to put a turboprop (heavily modified of course,minus prop,
output shaft to rear instead of front, electronic sound supression) with
appropriate gearing and extralarge compressure stage in a car. Talk
about a high performance car! More efficient too! Don't quote me, I
don't know too much about this. Any further enlightenment on this
subject would be welcome.

Eric Paulsen
Xref: sparky sci.aeronautics:1919 sci.environment:11028