HDTenEightyP/NetNews huggingface dataset:
From: zeke@wdl50.wdl.loral.com (Solly Ezekiel)
Subject: Re: Sonic Boom stuff.        :-)
Organization: Loral Western Development Labs
Date: Thu, 16 Apr 1992 19:29:58 GMT

>There were two XB-70 Valkyrie bomber prototypes.  One was lost in the incident
>you describe.  The F-104 got caught in the wake vortex of the XB-70 and

And, the XB-70 lost in the crash was the second prototype, which had a
lot of the "bugs" that had been found in the building of the first prototype
ironed out... sigh...

>Actually, I think it was cancelled because somebody thought that the
>soviets could hit it with their SAMs.   

I think that the reason the XB-70 was cancelled is that the Bomarc
(an early cruise missile) was then under development, and Congress
could not see the point in developing a "manned missile" to deliver
what an unmanned Bomarc could do.  (Or maybe the folks building the
Bomarc had more influence on the Hill).

>together at the front.  Also, what kind of heat supression stuff did the 
>Valkyrie use?  Certainly not black paint!

No, if I remember right the Valkyrie used its fuel (the tank sat more or
less in the geometric center of the aircraft) as a heat sink!  And the
forward part of the aircraft was cooled with refrigerated air.  I remember
reading somewhere that there was an emergency air bleed duct from the engine
intakes to flood the forward fuselage with intake air if the refrigerator
failed.

>saw the Wings episode about the XB-70 last night (what a magnificent
>machine that is!), and learned that during the first flight, the airframe

I agree!  IMHO (oh, I'm inviting flames here...) the XB-70 was one of the
most fascinating and ahead-of-its-time aircraft ever built.  Among the
innovations it sported was the ability to start without a ground cart,
a "droop snoot", and it was both the fastest and one of the largest aircraft
in the world when it was rolled out.  And the total power output from its
engines exceeds that of Hoover Dam.

>I don't dispute that compression lift has been shown in theory and highly
>controlled wind tunnel tests.  However, if you know of any functional aircraft
>that has used it as a major contributor of lift, I'd like to know about it.

This isn't exactly compression lift, but one of the Russian "ekranoplanes"
(the designation escapes me) actually has a pair of jet engines in the nose
that blow down and back, and the plane rides its reflected jet blast (this
works only in ground effect, of couse).  Not a shock wave, but a neat idea
nonetheless.

  +--------------------------+---------------+---------------------------+
  | "Asps!!  Very dangerous. |               | My opinions are not those |
  |     ...You go first."    |  Sol Ezekiel  |      of my employer,      |
  |          -- Sallah       |               |    Space Systems/Loral    |
  +--------------------------+---------------+---------------------------+
Newsgroups: sci.aeronautics
From: kanekawa@oahu.cs.ucla.edu (Nobuyasu Kanekawa)
Subject: Re: Flight Control Bus Spec
Organization: UCLA, Computer Science Department
Date: Thu, 16 Apr 92 17:54:10 GMT

Thank you for your follow-ups, Mr. Mark A Brown, and Mr. Ken Hoyme.
Your follow-ups will greatly help my understanding.

eeyore@dcs.qmw.ac.uk (Mark Anthony Brown;E200) writes:
: 
: Lack of a central bus master means that it's more fault tolerant, in theory,
: than 1553. 

    I agree. In case of MIL-STD-1553B, a bus controller is a single-failure-
point. So the official specification recomends its modification, - redundant
bus controller or redundant bus.  But I think huge redundancy is not always
smart (simple and clever) solution for fault-tolerance.  We have to consider
efficiency of redundancy, I gess.

  __  __     __                      _
 /  )/  )   /  )  /                 /_)
(  /   /   (  /__/ _    _  _       /   _          _
  /   /      /\   / )  / )/ ) (>  /_> / )  / / / / )
 /   (__/ * /  \__\/(_/ /  (__/\_/\__(_/(_(_(_(__\/(_
   (Email in Japan : kanekawa@hrl.hitachi.co.jp)
Newsgroups: sci.aeronautics
From: zeke@wdl50.wdl.loral.com (Solly Ezekiel)
Subject: Re: Sonic Boom stuff.        :-)
Organization: Loral Western Development Labs
Date: Thu, 16 Apr 1992 21:50:37 GMT

Another interesting point on the XB-70.  From what I have read, the
original RFP (request for proposals) that the Air Force issued specified,
among other things, that the aircraft be capable of taking off from
existing runways.  All of the contractors who responded to this RFP
decided that they could not meet this requirement as well as the requirements
for range, speed, and payload.  So what they proposed were aircraft that
met the range/speed/payload requirements, but that could not take off
from existing runways.  I have seen pictures of them; they were interesting,
to say the least- behemoths with multiple fuselages, a dozen or so
engines, and much more.  The Air Force rejected all proposals, and asked
the contractors to try again.

At this point, North American- who had never built a big bomber- decided
that if the Boeings and Douglases didn't know how to build this beast either,
they would give it a try.  Never having built a bomber, NA didn't "know" that
bombers are "supposed" to have their engines hanging off the wings (e.g.,
the B-17, B-24, B-29, B-47, B-52, etc.), and they proposed the compression
lift idea on an aircraft that had its engines internal to the fuselage.
The crazy idea worked, and the XB-70 was the result.

  +--------------------------+---------------+---------------------------+
  | "Asps!!  Very dangerous. |               | My opinions are not those |
  |     ...You go first."    |  Sol Ezekiel  |      of my employer,      |
  |          -- Sallah       |               |    Space Systems/Loral    |
  +--------------------------+---------------+---------------------------+
From: cabruen@athena.mit.edu (Charles Alan Bruen)
Newsgroups: sci.aeronautics
Subject: Need coordinates of Continents
Date: 10 Apr 92 00:15:15 GMT
Article-I.D.: athena.1992Apr10.001515.22938
Distribution: usa
Organization: Massachusetts Institute of Technology

Hello:

        Does anyone have a set of points that describe the earth
surface. Such as the lat and long coords of the continents. In my
program I would like to display a map of the earth that can be resized,
and the only way I can think of doing that is to have the coordinates of
the continest. I would really appreciate it if I could get a copy of the
coords or if somebody knows where I can look for them.

Thanks in advance.


Charles Bruen
cabruen@athena.mit.edu
From: minnich@gn.ecn.purdue.edu (Randolph J. Minnich)
Newsgroups: sci.aeronautics
Subject: Re: 747-400
Date: 6 Apr 92 23:42:30 GMT
Article-I.D.: gn.1992Apr6.234230.10009
Distribution: sci
Organization: Purdue University Engineering Computer Network

In article <1992Apr6.170704.11535@vax5.cit.cornell.edu> mm2j@vax5.cit.cornell.edu writes:
>Can anybody tell me about 747-400 performance, (range, cieling, endurance....)
>and also about the engines/avionics?
>The 747 is the most beautiful plane in the world, and I just want to find 
>out some real facts about it...


Try "Jane's All the World Aircraft".  I think that is the title.  It's on 
reserve at most engineering libraries.
-- 
      _/_/_/_/_/   _/_/   _/       _/ _/_/_/_/   _/         _/
     _/      _/ _/    _/ _/       _/ _/      _/    
    _/      _/ _/    _/ _/ _/    _/ _/      _/    _/    _/
   _/_/_/_/_/ _/_/_/_/ _/       _/ _/      _/  
Newsgroups: sci.aeronautics
From: mkfeil@bcrki9.bnr.ca ()
Subject: Re: Aeronautical misconceptions
Organization: Bell-Northern Research
Date: Tue, 07 Apr 92 22:26:35 GMT

In article <1992Apr07.022635.275@eng.umd.edu> crouse@eng.umd.edu (Gil Crouse) writes:
>It is an observable fact, that the
>air on a lifting surface moves faster over the upper surface than the
>lower surface and thus there is a pressure difference between the
>upper and lower surface and thus lift is generated.

I agree totally. It's just that the reason that air flows faster over the
top than the bottom has nothing at all to do with how far it has to flow.

>
>The counter example that Mr. Feil gave was that of a flat plate, but

That was not in my article, it was written by somebody else, but I basically
agree with the flat plate counterexample.

>I'll talk about the general case of a symmetric airfoil.  On a
>symmetric airfoil at a positive angle of attack, the stagnation point
>at the leading edge moves onto the lower surface as the angle of
>attack increases.  This implies that the distance from the stagnation
>point at the leading edge (LE) around the top surface to the
>stagnation point at the trailing edge (TE) is LONGER than the distance
>from the stagnation point at the LE around the lower surface to the
>stagnation point at the TE.  Thus the air traveling over the upper
>surface does in fact travel further than the air over the lower
>surface, EVEN FOR A SYMMETRIC AIRFOIL!!!!!

This may be true, but it has no relation to how fast the air flows. This
is the myth, and you have fallen into its trap by even bringing up this
example.

The air flowing over the top of the wing ends up at the trailing
edge well ahead of the air flowing over the bottom, especially at
higher angles of attack. 

>
>As has been hotly debated recently, this may or may not be a good
>explanation of the origin of lift, but is a valid observation about
>what occurs when lift is generated.

The valid observation is simply that air flows faster over the top of the
wing than the bottom. It is NOT true that the top vs bottom distance ratios
have anything at all to do with this (this was the main statement in the myth!)


Cheers!
Max
--
Max Feil                 
Bell-Northern Research    Internet: mkfeil@bnr.ca
P.O Box 3511 Station C,
Ottawa, Ontario, Canada.  - What do I know? I'm just a Nerd on the Big Ranch. -
From: geoffm@purplehaze.Corp.Sun.COM (Geoff Miller)
Newsgroups: sci.aeronautics
Subject: Re: Sonic Boom stuff.        :-)
Date: 16 Apr 92 20:35:36 GMT
Followup-To: sci.aeronautics
Organization: Sun Microsystems, Menlo Park, Ca.
NNTP-Posting-Host: purplehaze.corp.sun.com



In article <1992Apr16.192958.3938@wdl.loral.com> zeke@wdl50.wdl.loral.com 
(Solly Ezekiel) writes:

>I think that the reason the XB-70 was cancelled is that the Bomarc
>(an early cruise missile) was then under development, and Congress
>could not see the point in developing a "manned missile" to deliver
>what an unmanned Bomarc could do.  (Or maybe the folks building the
>Bomarc had more influence on the Hill).

I thought the Bomarc was a surface-to-air missile like the Nike.  Anybody
have any details about it?


>This isn't exactly compression lift, but one of the Russian "ekranoplanes"
>(the designation escapes me) actually has a pair of jet engines in the nose
>that blow down and back, and the plane rides its reflected jet blast (this
>works only in ground effect, of couse).  Not a shock wave, but a neat idea
>nonetheless.

I saw a recent AvLeak article about this aircraft, and the way I understood
it, these forward engines are simply to provide direct lift thrust.  The
airplane flies in ground effect, but that could be several hundred feet
off the surface, far beyond any reflected jet blast.  (As an indication of
their size, these forward engines are Kuznetsov NK-8s, the type originally
used for the Ilyushin Il-62 transport before they were converted to a more
powerful, higher-bypass design.  The forward propulsion is achievd with an 
NK-12MV turboprop, complete with contrarotating propellers, mounted atop the
vertical stabilizer -- the powerplant of the Bear bomber and the An-22 
military transport -- putting out a decidely nontrivial 14,795 eshp.)

I've seen drawings of a smaller, pure-jet design with engines mounted over
the wings YC-14 style, but I've never read anything about this one making
it into production.



Geoff


-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
Geoff Miller                    + + + + + + + +        Sun Microsystems
geoffm@purplehaze.Corp.Sun.COM  + + + + + + + +     Menlo Park, California
-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
Newsgroups: sci.aeronautics
From: sss@netcom.com (Small Systems Solutions)
Subject: Re: Aeronautical misconceptions
Date: Tue, 07 Apr 92 16:49:23 GMT
Organization: Netcom - Online Communication Services  (408 241-9760 guest) 

In article <1992Apr6.173315.480@ualr.edu> rjvictor@acs.harding.edu writes:

>  And, in complete accordance with the Bernoulli principle "the faster air
>exerts less pressure" and the ball is drawn to, and remains, in the center of
>the stream.

The fallacy is that you are assuming causality.  Properly stated, it is
"the air that exerts less pressure that travels faster."
-- 
Small Systems Solutions                   1563 Solano Avenue, Suite 123
sss@netcom.com                                  Berkeley, CA 94707-2116

The above-expressed opinions aren't necessarily
Newsgroups: wpi.students,sci.aeronautics,rec.aviation
From: megazone@wpi.WPI.EDU (MEGAZONE 23)
Subject: Spinoffs
Organization: WPI USAF -- United Society of Animation Fans
Date: Sat, 11 Apr 1992 23:10:15 GMT

Hello, it's me again. New term and a new class. This term I'm trying to 
do an oral report/paper on spinoff technology from government projects,
especially aerospace projects. Things such as laminar flow research, prop
fans, new materials, high performance engines, even lightning strike research
wold be great.

I have some data already, but I am trying not to overlook anything. So, if
you now of any materials or technology that was developed in a government
project that later became useful to the civilian market, please send me some
pointers so I can narrow my research down a bit. And please email replies,
for although I read wpi.students and sci.aeronautics I may not have the time
to search through the groups for replies. And I do not read rec.aviation any
longer due to time constraints.

And thanks to all who responded to my posts on the Aircraft Nuclear Propulsion
program.

Thanks and I hope to hear from you.

###############################################################################
# I have one prejudice, and that is against stupidity.  Use your mind, think! #
#Email megazone@wpi.wpi.edu  Moderator, WPI anime FTP site 130.215.24.1 /anime#
###############################################################################
From: wb8foz@mthvax.cs.miami.edu (David Lesher)
Newsgroups: sci.aeronautics
Subject: Re: Restated - Are the tires still pliable after space?
Date: 7 Apr 1992 22:36:47 -0400
Organization: NRK Clinic for habitual NetNews Abusers - Beltway Annex
Distribution: na
Reply-To: wb8foz@mthvax.cs.miami.edu (David Lesher)
NNTP-Posting-Host: mthvax.cs.miami.edu

{others said}
>I first heard it in relation to the 747.  Considering I lived in Seattle at
>the time...

Geeze!
Must of been a hell of a lot of noise to hear that tire blow
THAT far away.


{sorry - can't resist ;-}
-- 
A host is a host from coast to coast.....wb8foz@mthvax.cs.miami.edu 
& no one will talk to a host that's close..........................
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433
From: bdd0066@zeus.tamu.edu (Bryan, kick the tire and light the fire, Duke)
Newsgroups: sci.aeronautics
Subject: Re: Sonic Boom stuff.        :-)
Date: 16 Apr 92 04:32:00 GMT
Organization: Texas A&M University, Academic Computing Services
News-Software: VAX/VMS VNEWS 1.41

In article <1992Apr12.094123.39265@kuhub.cc.ukans.edu>, maddog@kuhub.cc.ukans.edu writes...
>When a sonic boom is heard, there are actually two shock waves hitting the
>observer.  The first is formed at the nose of the aircraft (assuming, of course
>it is the furthest forward point) and the second is at the trailing edge of the
>wing or aircraft where the pressure gradient returns to normal.  These two
>booms are so close together that they sound like one boom.
> 

It was my understanding that *every* nook and cranny make it's own
shockwave.  This would mean that the intakes, nose, rivits, wings, etc.
would each make their own wave.  I have a picture of a XF-17 (or
a model of) in a windtunnel at various mach #'s and *many* waves are
clearly visable.  Howwever, I think the biggest were from 
the wing and nose--so the above post would be mostly/sorta correct.  If
you were standing on the ground, the wave would move over you so fast
that your ears/brain could not tell any of the waves apart.  

bryan.
From: rone@carina.usc.edu (Ron A. Echeverri)
Newsgroups: sci.aeronautics
Subject: Re: Sonic Boom stuff.        :-)
Date: 12 Apr 1992 23:50:49 -0700
Organization: University of Southern California, Los Angeles, CA
NNTP-Posting-Host: carina.usc.edu

In article <1992Apr13.020133.25790@yuma.acns.colostate.edu> jb026939@longs.LANCE.ColoState.EDU (Jeffrey Bathke) writes:
>Concerning sonic booms, I've always wondered what would happen if you could
>fly a second plane "in" the shock wave cone of another plane.  (Both planes
>are moving the same speed).  I first wondered about this when I thought about
>hearing a "continuous" sonic boom.  By definition, that couldn't happen, 
>since the "boom" is the abrupt pressure change as the shock wave moves past
>an observer.
>Would the second plane be able to fly in the shock wave -- or would there be
>so much turbulence that the plane would fall apart?


Hm... i wonder. My conjecture (as valid as it may be) is that it'd be kind of
like flying a plane at exactly Mach 1; lotta turbulence and structural stress.


Can anyone enlighten us please? :)


-- 
.signature: defunct due to sig virus
Reconstruction in process
Newsgroups: sci.aeronautics
From: manuelp@bullet.ecf.toronto.edu (MANUELPILLAI Gerald N.)
Subject: Re: PROP THRUST CALCULATION
Keywords: PROPELLER, THRUST
Organization: University of Toronto, Engineering Computing Facility
Date: Thu, 9 Apr 1992 17:38:43 GMT

In article <train.702764018@qualcom> train@qualcom.qualcomm.com (Tom Rainwater) writes:
>
>  I have been looking for a formula which would yield propeller thrust in
>  either pounds or ounces as a function of pitch, diameter, RPM, and terminal
>  velocity. (rest deleted)  


Prop thrust is not an easy thing to do without handbooks.
Your best bet is to get a Hamilton Standard Propeller Data Book
(Usually known as the "Red Book" (Yellow Book for prop-fans)).
This gives all the required formulae for thrust calculations
at different op. conditions.

I'll try and define some of the quantities you need:

SHP = engine shaft horsepower, D = prop. diameter
N = shaft (not engine) RPM (n = RPS = RPM/60)
Vfwd = Forward Velocity (of a/c), Vk = Fwd. Vel. in knots
J = Advance Coeff. = Vfwd/(n*D) = 101.4 Vk/(N*D)

Activity Factor of Prop. Blade (AF) \ I won't give these here, but
Integrated Design Lift Coeff. (Cli) / you can pick these from the "Red Book"
			             (say AF = 140 +/- 20, Cli = .6 +/- .2)  

sigma = rho/rho0 = density ratio (at op. altitude)

Cp = Power Coeff. = SHP * (sigma)/(2000 * (N/1000)^3 * (D/10)^5) (eng. def.)
                  = Power/(rho * n^2 * D^4) (theoretical def.)

Ct = Thrust Coeff. = Thrust/(rho * n^2 * D^4) (could convert to eng. def.
					      (as above for Cp)
eta-p = Propulsive Efficiency = Useful Power/Supplied Power
                              = Thrust * Vfwd/SHP
                              = J * Ct/Cp
                              

When you start out you will have some of these quantities.  The others
(that you need) you look up in the Red Book, and voila!

Thrust = (Ct/Cp) * SHP / (N*D) * 33,000  (Thrust @ takeoff, J=0)
or
Thrust = 326 * eta-p * SHP / (Vk)
or
Thrust = 6610 * (N/1000)^2 * (D/10)^4 * (Ct*sigma)

I'm sure I butchered this attempt, but I hope it helps.  Feel free to
e-mail me if you have any questions.  (You should be able to find a
Ham. Stand. Red (or Yellow) book at any eng. library, it does a MUCH
better job of this!)

Gerald M
From: eeyore@dcs.qmw.ac.uk (Mark Anthony Brown;E200)
Newsgroups: sci.aeronautics
Subject: Re: Flight Control Bus Spec
Date: 15 Apr 92 09:18:23 GMT
Organization: Computer Science Dept, QMW, University of London

In <1992Apr8.214700.23888@cs.ucla.edu> kanekawa@oahu.cs.ucla.edu (Nobuyasu Kanekawa) writes:

>Hi !

>Does anybody know about the Flight Control Bus Spec, called
>ARINC [something] ?
>What is the difference from Mil-1553B ?

Its called ARINC 629 or DATAC. I worked with it a few years ago whilst I was
on what was to later be the 777 FCS team as a student engineer, but can't
remember any details. I don't think its a bus master-slave system like
MIL-STD-1553, however --- I think each box has a time slot on the bus
with random retry interval in case of collision, which means you get graceful
performance degradation as the bus becomes overloaded.

It should feature on the 777, and was being promoted by Boeing. That could give
you a lead in getting more information.

Lack of a central bus master means that it's more fault tolerant, in theory,
than 1553. I also think the bandwidth is up, and it can support
fibre optic in the standard. You can get a DATAC chip and get it to talk to a
bus via 1553 transceivers. I worked with a prototype chip, a massive
100-pin plus PGA, and a datasheet which lied. I was _not_ a happy bunny!

Hope this helps,
Mark.
--
Mark A. Brown                  | Ham radio callsign: G1ZVT   |
Department of Computer Science | telephone: +44 71 975 5220  | Nothing exceeds
QMW, University of London      | UUCP: eeyore@qmw-dcs.UUCP   | like excess.
Mile End Road, London E1 4NS   | JANET: eeyore@uk.ac.qmw.dcs |
Newsgroups: sci.aeronautics
From: michaeli@spock.usc.edu (Mark Michaelian)
Newsgroups: sci.aeronautics
Subject: The Aurora
Date: 17 Apr 1992 10:50:11 -0700
Organization: University of Southern California, Los Angeles, CA
Distribution: world
Reply-To: michaeli@spock.usc.edu (Mark Michaelian)
NNTP-Posting-Host: spock.usc.edu


In today's Los Angeles Times (Apr. 17), there was an article on the front page of the Metro section on the Aurora.  The article said that some of these supposed "earthquakes" that have been happening pretty regularly here in Southern California were actually sonic booms from the Aurora.  We've been talking on sci.aeronautics about this for the past couple of years, it seems to me.  The LA Times was quoting numbers of 4000 m.p.h., etc.

I was wondering if anyone had any new updates on the Aurora, and also if anyone knows if the article from the LA Times was actually credible in terms of their sources.

Thanks,
________

Mark Michaelian                     | 'If you live by the last second shot, you'll
USC Dept. of Aerospace Engineering  |    probably die by it too.'
email: michaeli@spock.usc.edu       |      - USC's loss in the NCAA Tourney to
                                    |         Georgia Tech
From: john@newave.mn.org (John A. Weeks III)
Newsgroups: sci.aeronautics
Subject: Question About Sonic Booms
Date: 9 Apr 92 04:57:19 GMT
Article-I.D.: newave.1413
Organization: NeWave Communications Ltd, Lake Wobegon, MN

Are sonic booms only created when an object passes through
the speed of sound, or does an object create a sonic boom
the entire time the object is moving faster than the speed
of sound.  In the first case, there would be a single boom
heard for a moment, while in the second case, there would
be a sonic boom `traveling' along with the object as it
moves across the country side.

Are sonic booms only associated with the speed of sound,
or are there other types of sonic booms created at other
speeds.  For example, does an airplane create a second
sonic boom when it passes through Mach 2, Mach 2.2, or
everytime it passes a Mach number?  (I picked Mach 2.2
because I recall that early high speed aircraft had great
difficulty with control problems around Mach 2.2.)

-john-

=============================================================================
John A. Weeks III               (612) 942-6969             john@newave.mn.org
NeWave Communications, Ltd.           ...uunet!umn-cs!kksys!tcnet!newave!john
Newsgroups: sci.aeronautics