HDTenEightyP/NetNews huggingface dataset:
From: kls@ohare.Chicago.COM (Karl Swartz)
Subject: Re: Safety and design rankings (was Re: Flight controls)
X-Submission-Date: Wed, 30 Dec 1992 07:00:42 GMT
Organization: Chicago Software Works
X-Submission-Message-ID: <1992Dec30.070042.13889@ohare.Chicago.COM>
Date: 29 Dec 92 23:02:31 PST

In article <airliners.1992.205@ohare.Chicago.COM> drinkard@bcstec.ca.boeing.com (Terrell D. Drinkard) writes:

>I don't think I'm giving anything away by saying that the folding wingtip
>option is still being studied, primarily by the New Large Airplane
>Division.  They apparently don't think they can get away with a 'damn the
>infrastructure' attitude.  :-)

It's also still being offered on the 777, as far as I know.  My
understanding was the part of United's reason for not ordering the
option was the weight penalty -- 3,900 lbs., or 2,000 for just the
hinges and stuff without the actuation mechanism, which allows easy
addition later on.  United preferred the weight savings and even at
that went with a higher MGTOW version in order to operate the 777
on Chicago to Hawaii routes, which are right at the range limits of
the A-market 777.

-- 
Karl Swartz	|INet	kls@ditka.chicago.com		
1-415/854-3409	|UUCP	uunet!decwrl!ditka!kls
		|Snail	2144 Sand Hill Rd., Menlo Park CA 94025, USA
 Send sci.aeronautics.airliners submissions to airliners@chicago.com

Newsgroups: sci.aeronautics.airliners
From: EGEISELMAN@FALCON.AAMRL.WPAFB.AF.MIL
Subject: VR COCKPIT QUESTION 12/16-3
X-Submission-Date: Mon, 28 Dec 1992 16:11 EDT
Followup-To: poster
Date: 28 Dec 92 22:47:45 PST

I have an exercise that I would like to propose to the net.  This exercise is
intended to demonstrate that the collective creativity and expertise of net
participants can be harnessed via a specific methodology.  I think the net
should be exploited as a population of subject matter experts and a source of
user input from which the extracted information may be applied to solving real
design problems.  Through an iterative process of concept refinement, using
the collective knowledge base of the net, it may be possible that otherwise
undiscovered design questions, problems, concepts, capabilities, and etc be
revealed.  I am going to take a look at this idea by doing the following:  I
will post a purposely vague design question to the participants of the net. Do
with the information what you will.  For those of you who choose to
participate in the exercise, e-mail your individual responses to me.  Please
use the date of the post you are responding to in the subject field of the
message.  Also, be sure to include the date of the post you are responding to
in the body of the mail message.  Feel free to submit questions to the net for
clarification and discussion but I will not extract information directly from
the net.  If you need a definition or have a question, ask the net first.
About four weeks after the original post I will submit an edited compilation
of the net response.  This post will hopefully act to spark more ideas, make
clarifications, and identify problem areas.  The refinement process will
continue.  The net may then respond to the new description in order to patch
holes, make corrections, and propose changes.  This iterative process will
continue until responses die off and/or the concept is solidified.  I will
document this process and report the results (I will post the report). 

--------------------------------------------------------------------------------
Sample question:

Let's say your are given a virtual reality system.  Your system consists of a 
high resolution wide field-of-view full color head mounted display devise 
(display), an extremely accurate head tracking system (transducer), and a 60Hz 
graphics generator (image generator).  Given this technology, how should it be
applied to the flight deck of a commercial airliner? 

--------------------------------------------------------------------------------

Note:  Please indicate, in your e-mail responses, if you would like your name
and/or affiliation to be excluded from any publication which may result from
this exercise.  Any information on personal background or experience you want
to include may be of some use.  All credit and acknowledgements will be made
as appropriate.  My thanks to all who participate.


e-mail to:  EGEISELMAN@FALCON.AAMRL.WPAFB.AF.MIL

Newsgroups: sci.aeronautics.airliners
From: yarvin-norman@CS.YALE.EDU (Norman Yarvin)
Subject: Re: Tire burn-out during landings
X-Submission-Date: 29 Dec 1992 17:32:00 -0500
Organization: Yale Computer Science Department
X-Submission-Message-Id: <1hqjl0INNsk6@CATHY.NA.CS.YALE.EDU>
Date: 29 Dec 92 22:53:48 PST

rdd@cactus.org (Robert Dorsett) writes:
> [...] (3) the *additional* wear and tear on the brakes, as they 
>must absorb the spinning energy, in addition to performing their normal 
>task of slowing down the airplane.  [...]

This additional energy is negligible.  Consider just the energy of the wheel
itself.  For a wheel which is rolling along the ground there is the relation:

	(rotational energy) = (some constant) * (energy of forward motion)

where the constant is independent of speed.  I seem to recall that for a
cylindrical wheel of uniform consistency, the constant is 2/7.  At absolute
worst the constant will be 1.  (This would occur if the entire mass of the
wheel were on the tread of the tire.)

Furthermore the energy of forward motion of the wheel is an insignificant
portion of the energy of the entire aircraft.  This goes by weight; if the
airliner weighs 100,000 pounds and a wheel weighs 300, the proportion of
energy in that wheel would be 3/1000 of the aircraft's energy.  Then, using
the 2/7 figure, the spinning energy of the wheel would be 3/1000*2/7 = .08%
of the energy of forward motion of the aircraft.

Assuming constant deceleration force, stopping distance would be lengthened
by that same .08%.  Even the weight of the mechanism required to speed up the
tires might be a bigger factor.

In any case, the practicality of preventing tires from disintegrating
depends on how fast tires presently disintegrate.  How much matter really is
there in that cloud of smoke?  Perhaps a gram per cubic meter of smoke?  And
how much tire is left on the runway?  Do they have to go out and scrape it
off now and then?  (I imagine not.)  Seems to me the loss of tire material
is negligible also.  Compared, that is, with the other costs of running the
airplane.

--
Norman Yarvin						yarvin@cs.yale.edu

Newsgroups: sci.aeronautics.airliners
From: wolfgang@trout.nosc.mil (Lewis E. Wolfgang)
Subject: Re: Tire burn-out during landings
X-Submission-Date: Tue, 29 Dec 1992 19:45:12 GMT
Reply-To: wolfgang@trout.nosc.mil
Organization: NCCOSC, NRaD Division
X-Submission-Message-Id: <1992Dec29.194512.10054@nosc.mil>
Date: 29 Dec 92 22:53:45 PST

In article 194@ohare.Chicago.COM, rdd@cactus.org (Robert Dorsett) writes:
 
>Strictly speaking, I don't see this as a gyroscopic effect.  We're just
>talking about the rotational momentum set up by a spinning tire, and what to
>do about it.

  (Stuff deleted)
>
> (3) the *additional* wear and tear on the brakes, as they 
>must absorb the spinning energy, in addition to performing their normal 
>task of slowing down the airplane. 
 
>(3) seems the major disqualifier of the idea.  With an inert tire, you'll 
>have *minor* control problems ("bump", and that's it), but the energy absorbed 
>by the tire in *spinning up*, on landing, in itself helps slow the airplane.  
>That smoke's the energy being absorbed by the tire.  If the tire's already up 
>to landing speed, I can easily see landing distances lengthened considerably.

  (lots more stuff deleted)

Robert, I think you have your mass off by several orders of magnitude.  If the
mass of the rotating tires is insignificant compared to the total mass of the
airframe (to negate the gyroscopic effect) then it will contribute negligibly
to the stopping distance.  

Consider, if you will, when the pilot manages to "grease" one on:  no noticeable
deceleration is observe at the moment of touchdown.  There may be a vertical
"bump",  but not a horizontal one.  (if there is no crosswind component)

IMHO you would see no measurable difference in rollout distance or residual heat 
in the brake system.

					Luck
					Lewie
					wolfgang@nosc.mil

 







Newsgroups: sci.aeronautics.airliners
From: megazone@obsidian.WPI.EDU (MegaZone23)
Subject: Re: Tire burn-out during landings
X-Submission-Date: 28 Dec 1992 03:13:01 GMT
Organization: WPI USAF -- United Society of Animation Fans
X-Submission-Message-Id: <1hlrbtINN5dp@bigboote.WPI.EDU>
Date: 28 Dec 92 22:47:43 PST

In article <airliners.1992.191@royko.Chicago.COM> Geoff.Miller@Corp.Sun.COM writes:
>megazone@obsidian.WPI.EDU (MegaZone23) writes:
>>When you spin a tire it acts as a gyroscope and will resists having it's 
>>course altered. This can make handling tricky as you would have 10 or more 
>>wheels all spinning on most airliners.
>First, I'd think that the mass of the spinning wheels, and therefore the
>magnitude of their gyroscopic effect on handling, would be insignificant
>compared to the mass of the rest of the airframe and payload and the 
>power of the control surfaces.

That's probably correct, although I don't have the weight of an average wheel
and tire on hand to compare it seems so. Though a 26" 12-speed tire is enough
to affect my 300lb body, I uspect the ratio of the gear to the aircraft weight
is MUCH less...

I too feel the major reason is cost, both for the hardware and lifetime costs.

>Second, assuming that the effect *was* significant, wouldn't it simply be 
>a stabilizing influence, i.e., a resistance to changes in attitude about 
>the longitudinal (roll) axis?  That doesn't sound all that hazardous.

Arg,old physics comes back to haunt me...

Making the large assumption that the mass is significant and the effect is as
stated; I can see a few problems in that course correction includes rolling
for turns, although I realize the angles used by airliners are a bit less than
what I use in a C-172....

But that is just speculation, thinking about it now I would agree that the 
mass difference makes the gyroscopic effects negligible.

###############################################################################
# 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#
###############################################################################



Newsgroups: sci.aeronautics.airliners
From: rdd@cactus.org (Robert Dorsett)
Subject: First Flights on airliners
X-Submission-Date: Thu, 24 Dec 92 06:30:34 CST
X-Submission-Message-Id: <9212241230.AA19239@cactus.org>
Date: 26 Dec 92 00:01:49 CST

I caught the tail-end of an episode of "First Flights," on the Arts & 
Entertainment Network, which dealt with advanced-technology airliners,
Wednesday night.  There were segments on the MD-12, the Fokker 100, and
the MD-80.  I only saw about the last 8 minutes, so assume the A320 or A310, 
and Boeing products, were featured in the first 20.  

A&E also shows a "First Flights" early Sunday evening, but I don't know
whether it's a repeat of the Wednesday show.  Whichever it is, they repeat 
that night's episode at 0530 EST on Monday.

There was nothing earth-shattering about what they were talking about (Neil
Armstrong: "So I guess the pilot's turning into more of a... supervisor...").
But the visuals are pretty, with little flicker.  "First Flights" is a nicely 
photographed, half-hour show, about *aviation*, and not all about blowing up 
things to a rock & roll beat, unlike "Wings." :-)



---
Robert Dorsett
rdd@cactus.org
...cs.utexas.edu!cactus.org!rdd

Newsgroups: sci.aeronautics.airliners
From: Tony Heatwole <HEATWOLE@LANDO.HNS.COM>
Subject: Re: Boeing 767 Cockpit Size
X-Submission-Date: Wed, 30 Dec 1992 13:21 EST
X-Submission-Message-Id: <CDC8CF352001CDF9@LANDO.HNS.COM>
Date: 30 Dec 92 12:55:24 PST

I have a reprint of the Harvard Business School case study on
the Boeing 767 (#9-688-040, Rev. 2/89).  It's a fascinating
look at technology, manufacturing, and the culture of the
Boeing Corporation.  With regard to the 767 crew size:

    "In August 1981, eleven months before the first scheduled
    delivery of Boeing's new airplane, the 767, Dean Thornton,
    program's vice president - general manager, faced a critical 
    decision.  For several years, Boeing had lobbied the FAA
    for permission to build wide-bodied aircraft with two-, rather
    than three person cockpits.  Permission had been granted late
    in July.  Unfortunately, the 767 had originally been designed
    with a three-person cockpit, and 30 of those planes were
    already in various stages of production.

    " . . . Engineers concluded that the thirty-first 767 was
    still far enough from completion that it, and all subsequent
    planes, could be built with two-person cockpits without
    modification.  Thirty planes, however, were in relatively
    advanced stages of production.  Some were nearly ready to
    to be rolled out and flown; others had complete cockpits but
    were not yet tested; others had bare cockpits without any
    electronics installed.  But since all thirty were being built 
    according to the plane's original, three-person cockpit design,
    all would require some modification.

    " . . . Customers were notified of the additional cost and
    delivery delay they could expect on these thirty planes.  The
    impact was not large: a small percentage increase in costs and
    an average delay of one month from promised delivery dates.
    All but one airline chose to have their planes built with 
    two-person cockpits."

So, the interesting question is, what was the *one* airline, and
what has become of their 3-person cockpit 767s?  Were these
planes later converted to 2-person cockpits?  I don't know the
answers, but I'm curious.

Interestingly, Boeing decided to complete the first 30 767s as
originally designed, for 3-person cockpits.  Then, they converted
the 30 (less the set to be delivered as 3-person cockpit) to
2-person operation as a batch.  This avoided the safety and
manufacturing problems of trying to convert a number of planes in
different stages of manufacture.

Tony Heatwole
Gaithersburg, MD
heatwole@hns.com

Newsgroups: sci.aeronautics.airliners,sci.aeronautics
From: Chris Scott <scottcr@WKUVX1.BITNET>
Subject: GPS (DGPS) RTCA std.?
X-Submission-Date: 21 Dec 92 13:52:52 CST
Followup-To: sci.aeronautics
Organization: Western Kentucky University, Bowling Green, KY
X-Submission-Message-ID: <1992Dec21.135252.4665@wkuvx1.bitnet>
Date: 28 Dec 92 22:49:50 PST


Clearly GPS is going  to change aviation navigation; The power
it has to create approaches into anywhere makes the imagination
wander...
--
Differential GPS has been demonstrated by (Trimble?) for the FAA
and I think it has been discussed somewhat in *Navigation*.

The concept is relatively simple, so it seems to me that all that is
lacking is 1. A correction data protocol standard, and 2. The
transport medium: (sat, vhf, atis burst, awos append...?)

Recently I read in *Avionics* a mention about GPS GIC ..GPS
Integrity Channel, but I have not heard about any RTCA or FAA
formal standards being proposed in this area.

Anyone know the direction that this is likely to go?

Chris Scott, C/E Public Radio, Western KY Univ, (502) 745-3834
SCOTTCR@WKUVX1.BITNET  FAX OFFICE: 745-2084 FAX HM: 781-1232
Newsgroups: sci.aeronautics.airliners
From: van_heel@rz-berlin.mpg.de
Subject: Martinair DC10 crash?
X-Submission-Date: 21 Dec 92 14:05:17 +0100
Organization: Rechenzentrum MPG Berlin
X-Submission-Message-ID: <1992Dec21.140517.7887@rz-berlin.mpg.de>
Date: 26 Dec 92 00:01:45 CST

Martinair DC10 crash around 9.30 am in Portugal.

According to a news broadcast which I heard at
10 o'clock this morning, a Martinair DC10 charter plane
had just crash-landed on a Portuguese airport with 322 passenger
aboard after being struck by lightning.  The plane exploded
immediately after the unsuccesful crash-landing.   


Marin van Heel

Newsgroups: sci.aeronautics.airliners
From: drchambe@tekig5.pen.tek.com (Dennis Chamberlin)
Subject: Re: Tire burn-out during landings
X-Submission-Date: 29 Dec 92 17:38:58 GMT
Reply-To: drchambe@tekig5.pen.tek.com (Dennis Chamberlin)
Organization: Tektronix, Inc., Beaverton,  OR.
X-Submission-Message-Id: <8105@tekig7.PEN.TEK.COM>
Date: 29 Dec 92 12:39:16 PST


In article <airliners.1992.192@royko.Chicago.COM> inc@tc.fluke.COM (Gary Benson) writes:
>
>Does anyone have any estimates about the costs using the current "cloud of
>smoke" and friction method of landing? How much does one of those tires
>cost? 
>
I recall an old issue of AWST that described the certification flight test
program for the first 747. The flight test budget included a 3 million $
line item for "Wheels, tires, and brakes".

At least one of these tests was known to be destructive. The worst-case
demonstration of a takeoff abort would seem to thoroughly cook all of the 
tires and brakes. I don't know if any of the wheels were savable.


Newsgroups: sci.aeronautics.airliners
From: drinkard@bcstec.ca.boeing.com (Terrell D. Drinkard)
Subject: Re: Economics of new vs. older planes
X-Submission-Date: Tue, 29 Dec 1992 23:46:42 GMT
Organization: Boeing
X-Submission-Message-Id: <C01opw.76F@bcstec.ca.boeing.com>
Date: 29 Dec 92 22:53:50 PST

In article <airliners.1992.165@ohare.Chicago.COM> John DiMarco <jdd@cdf.toronto.edu> writes:
>I understand there's an airfield in Arizona where unused airliners are parked
>for extended periods. I'm wondering, considering the economic doldrums
>most airline companies seem to be in, why these planes are not put into
>use in lieu of buying new ones? 
>
>The answer, I think, would depend on the difference in operating costs between
>new and older planes. Could someone with a better understanding of these issues
>shed some light on this? Solid numbers (eg. purchase prices of new vs. used
>planes, fuel consumption differences, etc.) would be highly appreciated.

Well, it is not a simple question John asks here.  For instance, lots of
727-200s parked at Davis-Monthan, and at Mojave.  A used 727-200 Advanced
should bring between one and two million (prices are subject to
inbelieveable fluctuations).  727s of any sort are no longer available new.
The nearest replacement airplane, regardless of what the Boeing PR office
may say, is the Airbus A320 - catalog price of about $41 MILLION.  Granted,
the 727 has a fuel burn half again larger for the same route, same payload,
same speed, but it costs a whole lot less to acquire.  Unfortunately for
727 owners, they are stage two noise compliant.  This means that they will
no longer be allowed to operate in the domestic US after 2000 or so.
Europe is much the same.  This short economic life must be take into
account before purchasing our hypothetical 727.

Another aspect is if one has already purchased a 757, for instance, then
one is still obligated to make the loan payment each month.  And the loan
payments are huge.  So, if you already have the airplane, you may as well
put it to work, especially if it is more efficient than some other
airplane.

Lastly, I'd like to mention that over-capacity is one primary problem that
the airlines are trying to deal with.  Adding more available seat miles is 
not a solution.

-- 
Terry
drinkard@bcstec.boeing.com
"Anyone who thinks they can hold the company responsible for what I say has
more lawyers than sense."

Newsgroups: sci.aeronautics.airliners,rec.travel.air
From: davidm@questor.rational.com (David Moore)
Subject: Re: Surviving a Commercial Aircraft Accident
X-Submission-Date: Tue, 22 Dec 1992 20:48:48 GMT
Organization: Rational
X-Submission-Message-Id: <davidm.725057328@questor>
Date: 26 Dec 92 00:01:48 CST

eandersn@mach1.wlu.ca (Niels Ejvind Andersen) writes:

>If the aircraft has ditched, don't inflate your life vest until you are
>outside the aircraft. 

One is usually instructed to inflate one half of the life vest while
in the cabin, and to fully inflate the vest once you have left the
aircraft. Were reasons given why this alternative procedure is
preferable?

Did they say anything about US flights on which life vests are not provided?
I find it hard to believe that those floating cushions are of any value at all.

There is one other point which comes across clearly from the crew demonstrations - it
is important to remain smiling at all times during emergency procedures. Would 
I be right in thinking this is to reduce panic?

Newsgroups: sci.aeronautics.airliners
From: drinkard@bcstec.ca.boeing.com (Terrell D. Drinkard)
Subject: Re: Safety and design rankings (was Re: Flight controls)
X-Submission-Date: Tue, 29 Dec 1992 23:35:50 GMT
Organization: Boeing
X-Submission-Message-Id: <C01o7s.6up@bcstec.ca.boeing.com>
Date: 29 Dec 92 22:53:49 PST

In article <airliners.1992.163@ohare.Chicago.COM> kls@ohare.Chicago.COM (Karl Swartz) writes:
>In article <airliners.1992.144@ohare.Chicago.COM> rdd@rascal.ics.utexas.edu writes:
>>I would suggest not: the former is more of a derivative, the latter more of
>>a new type, with its new wing (which was designed to support the all-upper-
>>deck concept, plus maybe one more derivative after that) ...

Both airplanes are derivatives, actually.  The MD-11 was certified under
the DC-10's certification basis.

>My understanding was that the 747-400 does *not* have a new wing but
>rather a tweaked version of the original.  I recall some statement
>from Boeing regarding the lack of winglets on the 777, which noted
>that the 777 had a new wing and starting from a clean slate it was
>more efficient to not have them, whereas working from an existing
>design as with the 747-400 it was helpful to have them.

I can't speak to exactly how much of the 747-400's wing design could be
considered 'new', but I do know that it was modified extensively to
change the pressure distribution across the wing - particularly the
inboard wing where we were seeing double shocks on the older models.

>What I've seen suggests the F.100 is quite advanced, probably not far
>behind the A320 and perhaps closer to the Airbus philosophy than to
>Boeing's.

The Fokker 100's flight deck is much more Boeing-esk than Airbus-ish.
There are control columns, and the FMS is very similar to the Boeing
models.  The F 100 does have envelope protection, as do the Airbus
airplanes, but I don't think you would find it much different from
what is already flying.  It is a very advanced flight deck, very
clean.

>>                    INS/PMS, conventional otherwise
>
>Ok, I'll risk it ... what's PMS?  (We're talking about airplanes!)

Could it be the Performance Management System, a la Douglas MD-80? :-)

>I've always wondered just what the flight engineer really does on a
>767 equipped for three flight crew.  I believe QANTAS does this.
>Also, some A310s lack the FFCS (Forward Facing Crew Cockpit) having
>instead what I assume is a cockpit more like an older A300.  All of
>these are due primarily to union/labor pressures.

You are quite right, three-crew cockpits are union requirements on some
airlines.  The flight engineer on a 767 would do the same job done
on other three-crew airplanes - deal with onboard systems.  All those
nifty controller boxes are left behind in Seattle.  :-)


-- 
Terry
drinkard@bcstec.boeing.com
"Anyone who thinks they can hold the company responsible for what I say has
more lawyers than sense."

Newsgroups: sci.aeronautics.airliners