TWA 747 crash - flight 800 (JFK-CDG)
Karl Swartz
>The 747 in question was a veteran 747-100, N93119 (f/n 17119).
>The aircraft was built and delivered to TWA in 1971.
Thanks for the additional info! With that, here's a bit more. It's
variously listed as a 747-125/131 or just a 747-131. As the -125
suggests, it was originally intended for Eastern Airlines. TWA took
up at least four aircraft that were in production, but not complete,
when Eastern cancelled their 747 order. This was the last of those
four. It's first flight was August 18, 1971, and it was delivered to
TWA on October 27. Boeing bought it back on December 15, 1975, with
the intention of delivering it to the Imperial Iranian Air Force as
their "registration" (it appears to be a military serial number) 5-288
but for some reason the deal was not completed and the next day, TWA
bought the plane back from Boeing. (The other three TWA 747s from
the Eastern order did go to Iran earlier in 1975 and apparently are
still there.)
The accident aircraft was msn 20083, the 153rd 747 built and the
newest of the ten 747-100s in TWA's fleet as of March 1995. All ten
were equipped with Pratt and Whitney JT9D-7A engines and had a MGTOW
of 734,000 lbs -- heavier than the original 747-100 spec but not as
high as some, which go up to at least 750,000 lbs. (The 747-400 has
a MGTOW of at least 875,000 lbs. The current 747-600X proposal is
750,000 lbs with fuel or payload; MGTOW will be 1,126,000 lbs!)
--
Karl Swartz |Home k...@chicago.com
|Work k...@netapp.com
|WWW http://www.chicago.com/~kls/
Moderator of sci.aeronautics.airliners -- Unix/network work pays the bills
Karl Swartz
A TWA 747-100 exploded about 15 minutes after departing New York's JFK
on a flight to Paris-CDG this evening, with wreckage falling into the
water about 20 miles south of Mariches Inlet on Long Island, 40 miles
east of JFK. Flight 800, scheduled to depart at 700p, took off just
before 830p, and controllers in Boston reportedly lost contact with
the flight at 840p when it was at an altitude of approximately 7,500
ft.
Reports vary on how many people were about but the most reliable story
seems to be 229, 212 passengers, 14 flight attendents, and three pilots.
According to TWA, a flight to Rome was cancelled or delayed and passen-
gers from that flight were protected on flight 800. It's not clear if
this means there may have been more than 229 people aboard or not; it
may account for the late departure.
US Coast Guard boats and helicopters searching the area, hampered some-
what by night and fog, had already recovered some bodies and body parts.
There were reports of life rafts in the water but these apparently were
dropped by the USCG and did not come from the TWA plane. A Coast Guard
spokesman offered little hope of finding any survivors.
The phone number for information on friends or relatives aboard the
flight is 1-800/438-9892, or call TWA reservations at 1-800/221-2000.
They don't have much info yet, though.
The aircraft had been at JFK for three hours after arriving from Athens
operating flight 881. It was reported as a 747-100, but I don't have
any information yet as to which one it was. In particular, I don't
know if it's the one that recently passed the 100,000 flight hour mark,
apparently a record for any aircraft.
According to last year's JP Airline Fleets, accurate through March 1995,
TWA operated 10 747-100s (and three 747-200Bs). Eight were -131 models
built for TWA in 1970 and 1971; the other two were -156 models built
for Iberia originally and acquired by TWA in 1980 and 1981. All ten
747-100s were configured with two-class seating, 29 F and 396 Y, a total
of 425. With 212 passengers, that's a 50% load factor, stunningly low
in a summer when many trans-Atlantic flights are sold out in all classes
well in advance.
TWA's 1995 Annual Report shows only 11 747s at the close of 1995, (both
retirements were 747-100s, I believe) with plans to increase that to 16
by the end of this year through purchases of used aircraft. One "new"
747-100 was added earlier this month, an ex-Continental (People Express
before CO and originally Alitalia) 747-143, but it's unlikely it would
have entered TWA service already.
The $64,000 question ... what happened? Nobody knows yet, and with the
debris underwater the investigation will not be easy. Obviously there
is lots of speculation about a bomb (fueled no doubt by the fact that
the aircraft had come in from Athens, which has a poor security rating)
but at this point it's just that, speculation. One former NTSB official
on this evening's news said it did NOT appear to be a bomb, in his
opinion. I didn't catch the whole reasoning, unfortunately.
All of this came just hours after TWA announced 2nd quarter earnings of
$25.3 million or 46 cents per share, up 387% percent from $5.2 million
in last year's 2nd quarter. (The result was still well below analysts'
estimates of about 65 cents per share.)
Allen M. Generoso
The 747 in question was a veteran 747-100, N93119 (f/n 17119).
The aircraft was built and delivered to TWA in 1971.
James R. Generoso
Jam...@worldnet.att.net
Karl Swartz
A popular theory for the crash of TWA flight 800 seems to be that it
was shot down using a missile (a Stinger?) from a hand-held launcher,
either launched from short (allegedly out of range) or from a boat.
Reports of a streak in the sky and a radar blip merging with TW 800
are used to support this notion, though the military says the blip was
a momentary electronic phantom and that the 747 was both too high and
too far off shore to be within range of such a missile. Let's assume
it was *possible*, that is, range and altitude aren't an issue.
I still have one problem with the missile theory. Korean Airliners
007 was shot down by two missiles launched from a Soviet Sukhoi-15
fighter, 6-12 km (the reports I have are unclear) behind it. I assume
that a fighter could carry missiles with significantly more punch than
any sort of hand-held missile. Yet there was no fireball, no in-
flight breakup of KE 007. One missile hit near the tail while the
second ripped off a substantial portion of the left wing. Far from an
explosion and fireball, followed by breakup of the airframe, the plane
had electric power for another minute and 44 seconds, allowing the CVR
to record a hopeless struggle as the pilots tried to regain control of
the crippled 747. The evidence indicates the airframe was intact for
the entire twelve minutes from missile hit to impact with the water.
Perhaps the Soviet air-to-air missiles are so poor that they can't
match the punch of a hand-held Stinger, or maybe you just need a
really lucky shot to trigger an instant fireball. I'm skeptical,
though I'm willing to consider a solid argument that even a small
missile could indeed have produced the observed result.
Andy Tompson
Karl Swartz wrote:
>
>........
> One former NTSB official
> on this evening's news said it did NOT appear to be a bomb, in his
> opinion. I didn't catch the whole reasoning, unfortunately.
My understanding on this was that there were reports of a sequence of
happenings....some kind of initial fire (that looked like a flare), a
larger explosion slightly later, and possible a third after that. Plus,
there were some indications that the initial fire was not "centered" on
the fuselage, but off to the side (as possibly interpreted from some
perceived rotating motion). Neverthless, I heard the NTSB guy on CNN say
that the fact there was a sequence of explosions and the fact that the
original "fire" may have been off center could indicate and origin away
from the fueselage [where a bomb in the baggage would be stored]. Of
course, I keep thinking about someone stuffing something in the landing
gear area while on the ground, but do we need more speculation?
--
Andrew F. B. Tompson: Earth Sciences Division
Lawrence Livermore National Laboratory, L-206
voice: (510) 422-6348
fax: (510) 422-3118
email: af...@llnl.gov or an...@s50.es.llnl.gov
awk...@aol.com
Remember that old B747 sometimes use to lost some of their engines. May
someone could find out, if the Boeing Strut-Modification SB has been
performed at this TWA 747 !
Tas Papadopoulos
How true is the rumor that the plane stopped somewhere after Athens for
"re-fueling"? Supposedely it was on the ground for about 1.5 hours. This
is from a passenger. Didn't get the place, but it was supposedly a very
large airport built during WWII.
Don Stokes
In article <airliners...@ohare.chicago.com>,
Karl Swartz <k...@ohare.Chicago.COM> wrote:
>A popular theory for the crash of TWA flight 800 seems to be that it
>was shot down using a missile (a Stinger?) from a hand-held launcher,
>either launched from short (allegedly out of range) or from a boat.
>Reports of a streak in the sky and a radar blip merging with TW 800
>are used to support this notion, though the military says the blip was
>a momentary electronic phantom and that the 747 was both too high and
>too far off shore to be within range of such a missile. Let's assume
>it was *possible*, that is, range and altitude aren't an issue.
>
>I still have one problem with the missile theory. Korean Airliners
>007 was shot down by two missiles launched from a Soviet Sukhoi-15
>fighter, 6-12 km (the reports I have are unclear) behind it. I assume
>that a fighter could carry missiles with significantly more punch than
>any sort of hand-held missile. Yet there was no fireball, no in-
>flight breakup of KE 007. One missile hit near the tail while the
>second ripped off a substantial portion of the left wing. Far from an
>explosion and fireball, followed by breakup of the airframe, the plane
>had electric power for another minute and 44 seconds, allowing the CVR
>to record a hopeless struggle as the pilots tried to regain control of
>the crippled 747. The evidence indicates the airframe was intact for
>the entire twelve minutes from missile hit to impact with the water.
Well, I'm pretty skeptical about the missile theory too, but let's take a
look at the two types of attack:
The Russian missiles were fired from an aircraft _behind_ the target.
The missiles fired were a radar guided one, which went for the tail, and
a heat seeker which locked onto the tailpipe of one of the engines. I
believe the engine hit was an outer one, but it's been a while since I
read about that incident.
>From behind a 747, the bulk of the radar echo is the tail -- the
fuselage is behind the tail, and the tail itself is pretty big.
Note that neither the engines nor the tail contain fuel tanks. The wing
in the immediate area of the engine pylon doesn't contain fuel either;
thus there's a fair chance the tanks-containing parts of the aircraft
went their separate ways basically intact or spewing fuel into airspace
that wasn't on fire.
On the other hand, a radar guided missile fired from _underneath_ the
plane would (probably) "see" the wing root area as returning the largest
echo, and aim for that, as long as it stayed underneath, as in the case
if the missile was fired from a point forward of the aircraft. That area
does contain fuel, and if an explosion and fire in that area caused the
wing root to fail, the whole structure would quickly disintegrate.
A heat seeking missile would of course still go after the engines; Maybe
if it hit an inboard engine the debris could rip into the wing root and
burn the plane. I dunno.
I have seen photos of a Pan Am 707 out of San Francisco with its wing
burning after the number 4 engine split a turbine disk, disintegrated and
departed. The wing burned and broke off at the No. 4 pylon. The pilot
managed to nurse the plane back to an airfield after shutting down fuel
flow to the departed engine, putting the fire out. Jet fuel fires can
burn through structures quite nicely if you can get them started in the
first place.
--
Don Stokes, Network Manager, Victoria University of Wellington, New Zealand.
d...@vuw.ac.nz(work) d...@zl2tnm.gen.nz(home) +64 4 495-5052 Fax+64 4 471-5386
Timo Niroma
In article <airliners...@ohare.Chicago.COM>, k...@ohare.Chicago.COM
(Karl Swartz) says:
>
>A popular theory for the crash of TWA flight 800 seems to be that it
>was shot down using a missile (a Stinger?) from a hand-held launcher,
>either launched from short (allegedly out of range) or from a boat.
>Reports of a streak in the sky and a radar blip merging with TW 800
>are used to support this notion, though the military says the blip was
>a momentary electronic phantom and that the 747 was both too high and
>too far off shore to be within range of such a missile.
All I have heard in Finnish news,
1. the radar echo
2. one pilot seeing some outside the plabe before the explosion
3. the plane crashing into two peaces
4. the pilot saying, that there eas first a small explosion and then a
bigger one
5. a possible mayday but not much else
point in my opinion to one direction: a meteorite.
As NASA recently announced the amount of meteorites pouring into our
atmosphere is grossly underestimated.
And they have hit cars, they have hit houses, here in Finland, and there
in US.
I think it's only a question of time when one hits an aeroplane.
The danger is even bigger than for a car, because there is much less
atmosphere above an aeroplain to break up an meteorite and still they
sometimes reach the ground.
I suggest this only because this is seldom taken as a real possibility as
it should.
Timo Niroma
an amateur astronomer
Jan-Peter Munk
Karl Swartz wrote:
>
> Perhaps the Soviet air-to-air missiles are so poor that they can't
> match the punch of a hand-held Stinger, or maybe you just need a
> really lucky shot to trigger an instant fireball.
A couple of years ago I visited a German Air Force base, where some
MiG-29 Fighter were operated. These Fighter belonged to the former East
German Air Force. In this context we were told that it is a special
feature of Soviet/Russian air-to-air missiles that they can rip off a
"substantial portion of the wing [kls]". So enemy pilots should have a
chance to get escaped out of their cockpits using their emergency launch
seats...
--
Jan-Peter Munk Daimler-Benz AG
Research and Technology
mu...@DBresearch-berlin.de Alt-Moabit 96a
JPM...@t-online.de D-10559 Berlin
--
[My opinions...]
Andrew Cameron
k...@ohare.Chicago.COM (Karl Swartz) wrote:
> It's first flight was August 18, 1971, and it was delivered to
>TWA on October 27. Boeing bought it back on December 15, 1975...
> ........and the next day, TWA
>bought the plane back from Boeing.
(extract from original posting)
My records from two UK sources suggest that this aircraft was sold to
Boeing December 15, 1975 and that TWA bought again on 16th December,
1976, one year and a day later. This is supported by a quick
calculation on the hours of the airframe against others in the TWA
fleet - 87964 to 23rd January 1995, about 8000 hrs (2 years
equivalent) behind c/n 19675 then at 96194 hours. I don't have any
other evidence, but I had no interest in this 20 years ago.
Pete Mellor
Andy Tompson <af...@llnl.gov> asks on Sun Jul 21 21:47:17 1996:-
> I keep thinking about someone stuffing something in the landing
> gear area while on the ground, but do we need more speculation?
Perhaps not, but would someone care to comment on the following?
1. It couldn't have been a bomb with a timer, since the aircraft
was delayed on the ground for an hour before take-off, and it
would have exploded on the runway.
2. Exception to 1. is that a bomb with a timer was loaded at Athens,
but with a *very* long time set to detonation. Again, that means
that the attacker either did not care when it blew up, or set
the timer for the mid-ocean cruise, and the delay meant that it
exploded a few minutes after take-off.
3. If a bomb with a barometric detonator was loaded at New York,
why did it not explode before 13,000 odd feet, if it was in a
baggage hold maintained at the same pressure as the cabin,
i.e., equivalent to 5,000 feet altitude?
4. If it was a bomb, that (IMHO) leaves us with a barometrically
detonated device stuffed into the landing gear or attached
somewhere outside the pressurised cabin/baggage hold at NY
(or perhaps a device detonated by radio signal?).
Peter Mellor, Centre for Software Reliability, City University, Northampton
Square, London EC1V 0HB, UK. Tel: +44 (171) 477-8422, Fax: +44 (171) 477-8585
E-mail: p.me...@csr.city.ac.uk
-----------------------------------------------------------------------------
Karl Swartz
>3. If a bomb with a barometric detonator was loaded at New York,
> why did it not explode before 13,000 odd feet, if it was in a
> baggage hold maintained at the same pressure as the cabin,
> i.e., equivalent to 5,000 feet altitude?
Cabins are not pressurized to 5,000 feet equivalent -- it's closer to
8,000. Also, pressurization doesn't just kick in and hold steady at
the desired altitude, so a device set to trigger at, say, 6,000 ft
might not trip until the aircraft reaches 13,000+ ft, with the cabin
altitude gradually increasing to that point.
Corsair
>I still have one problem with the missile theory. Korean Airliners
>007 was shot down by two missiles launched from a Soviet Sukhoi-15
>fighter, 6-12 km (the reports I have are unclear) behind it. I assume
>that a fighter could carry missiles with significantly more punch than
>any sort of hand-held missile. Yet there was no fireball, no in-
>flight breakup of KE 007. One missile hit near the tail while the
>second ripped off a substantial portion of the left wing. Far from an
>explosion and fireball, followed by breakup of the airframe, the plane
>had electric power for another minute and 44 seconds, allowing the CVR
>to record a hopeless struggle as the pilots tried to regain control of
>the crippled 747. The evidence indicates the airframe was intact for
>the entire twelve minutes from missile hit to impact with the water.
Bear in mind that the KAL 007 wasn't carrying as much fuel as it was nearing
the end of it's flight. The 747 that crashed was fully-fueled having just
taken off. In addition, both A/A missiles didn't really strike areas that
would have been filled with fuel. IF a SAM downed TWA 800, it may have gone
for the engines as the hottest part, which are directly below the fuel tanks.
--
Corsair
Web CAG of The Unofficial "Jolly Rogers" Site
http://www-home.calumet.yorku.ca/mdonalds/www/home.htm
Karl Swartz
>controllers in Boston reportedly lost contact with the flight at 840p
>when it was at an altitude of approximately 7,500 ft.
One of the more confusing aspects of the reporting on TWA 800 has been
the wild variations in altitude. I finally saw some material over the
weekend that helped explain this.
Flight 800 was being tracked by a radar station at Islip, NY, which
makes one 360-degree sweep every 12 seconds. At 20:31:08 EST, the
radar sweep picked up TWA 800 with a transponder response indicating
an altitude of 13,700 ft. On the next sweep, there was no response
from the transponder, and during that interval the CVR and FDR both
stopped recording abruptly. The sweep after that one picked up two
distinct pieces of flight 800. According to the San Francisco
Chronicle, "Investigattors have no evidence of a major breakup of
the plane before the fireball. They believe the fireball happened
5,000 feet below the initiating event, a conclusion reached through
a careful correlation of reports from pilots on other planes and
with the help of a private Long Island company that provides a shadow
air tracking service."
The 7,500 ft altitude may have corresponded to the two pieces on the
first post-breakup radar sweep of the debris. The 8,500 ft reports
clearly correspond to the fireball, while the 13,700 ft is the rough
altitude at which the "initiating event" occurred.
Bob Niland
Karl Swartz (k...@ohare.Chicago.COM) wrote:
> Reports of a streak in the sky and a radar blip merging with TW 800
> are used to support this notion, though the military says the blip was
> a momentary electronic phantom and that the 747 was both too high and
> too far off shore to be within range of such a missile.
What about space junk? Sooner or later a meteorite or some re-entering
human-launched object is going to hit an aircraft in flight (if indeed
it hasn't happened already, and been closed as "unknown" or "pilot
error").
I assume that since NORAD (or whatever they're called these days)
routinely tracks object large enough to be a threat to the shuttle, that
re-entering man-made stuff can be easily ruled out (if the NTSB thinks
to ask them). Is this question routinely asked and answered in air
crashes?
The talking heads (I hesitate to to call them "reporters") are telling
us that the NTSB/FBI have a short list of three possible causes that
have not been ruled out (as of 7/26/96). The way they are worded
suggests that being struck by, say, a meterorite, has been ruled out.
Has it? If so, how?
Regards, 1001-A East Harmony Road
Bob Niland Suite 503
Internet: r...@csn.net Fort Collins
Unless otherwise specifically stated, Colorado 80525 USA
expressing personal opinions and NOT
speaking for any employer, client or
Internet Service Provider.
Scott & Cynthia Sullivan
Karl Swartz wrote:
>
> A popular theory for the crash of TWA flight 800 seems to be that it
> was shot down using a missile (a Stinger?) from a hand-held launcher,
> either launched from short (allegedly out of range) or from a boat.
> ... I'm skeptical,
> though I'm willing to consider a solid argument that even a small
> missile could indeed have produced the observed result.
I agree with Karl. I am in the air force, and while not an expert on
SAM's or their capabilities, I do have some education on the subject. It
seems to be unlikely a hand held missile could cause the amount of damage
indicated in this incident. My understanding is that such missiles have
a warhead of only a few pounds, and limited lethal ranges (about 2-3
miles). Flight 800 was 2+ miles high at the time.
If it had been a missile, I think a radio call would have occured, and
the plane would not have broken up completely as is the case.
Scott Sullivan
Paul Kronfield
Has anyone considered the fact that IRAN has a number of German
manufactured diesal-electric submarines capable of long range patrols,
and a number of American-made hawk antiaircraft missles? It wouldn't
be difficult for a submerged sub to monitor air traffic control
transmissions from an exposed whip antenna, hear the clearance for
takeoff and the runway number, surface, fire a hawk, and instantly
submerge... Or if the submarine theory is too far out, how about a
tramp steamer with a hawk?
A stinger probably couldn't have done it, but a hawk would make small
work of a 747.
--
Paul Kronfield
Houston, Texas, USA
p...@geoprobe.com
For FREE international and domestic long distance faxing
see.... http://www.geoprobe.com
doug wakefield
Timo Niroma (timo....@tilmari.pp.fi) wrote:
: point in my opinion to one direction: a meteorite.
:
: As NASA recently announced the amount of meteorites pouring into our
: atmosphere is grossly underestimated.
Just an additional statistic, According to Author Ken Davis, the Chances
of getting in a car accident are 100 to one, in a plane accident 20
thousand to one, being hit by a meteor 7 thousand to one. People do die
in plane crashes enough so people worry about flying, maybe the meteorite
idea should be taken a little more seriously.
At least they would find evidence on the ocean floor of a foreign rick if
it's true.
Timo Niroma
<airliners...@ohare.Chicago.COM>
X-Newsreader: WinVN 0.91.6
In article <airliners...@ohare.Chicago.COM>, Andy Tompson
<af...@llnl.gov> says:
>
>Karl Swartz wrote:
>> One former NTSB official
>> on this evening's news said it did NOT appear to be a bomb, in his
>> opinion. I didn't catch the whole reasoning, unfortunately.
>My understanding on this was that there were reports of a sequence of
>happenings....some kind of initial fire (that looked like a flare), a
>(cuts)
>but do we need more speculation?
I have got much post in my e-mail that think that the the theory of a
meteorite strike is a real possibility.
To those who have said that there would be clear trace after such a huge
event, I would answer that the first trace may be very small.
The possible meteorite can have been only one centimeter or one inch in
diameter or even smaller.
The point is that a meteorite has a speed a several tens of kilometers in
second or several tens of miles in second.
Think it. Compare with a bullet can do. And how slow it is.
If the point of hit has been strategic, a one centimeter meteorite
causing 15 centimeter wide a gap and tremendous heat, near is not much
more needed.
There is a tremendous explosion that could explode one of the motors or
fuel channel. Thus the two explosions.
Think the speed, that's the key.
What news has come here to Finland, at least ten people have seen a flash
outside the aeroplane before the aeroplane exploded.
The other news that where in our newspapers was that the it was the other
wing, not the cabin with the bags that got the first hit.
So I answer we really need no more speculations, and I'm sure that the
commission that tries to resolve this case does a good and accurate work.
But as also has been said, one cannot see a thing that is not in his/her
horizon.
Let's not speculate, let's make hard investigation work, but let's take
into account this one, albeit rare, but at the same time very real
possibility.
And I think there this time more than ever all reason to take it as a
REAL possibility.
Timo Niroma
amateur astronomer
Dwayne Allen Day
Bob Niland (r...@csn.net) wrote:
: The talking heads (I hesitate to to call them "reporters") are telling
: us that the NTSB/FBI have a short list of three possible causes that
: have not been ruled out (as of 7/26/96). The way they are worded
: suggests that being struck by, say, a meterorite, has been ruled out.
: Has it? If so, how?
When someone crashes their car into a tree late at night and there's no
indication of alcohol in the blood stream do the police instantly suspect
murder? No. They start with the most likely causes, such as someone
falling asleep at the wheel.
When conducting an accident investigation, one does not start with an
infinite list of possibilities and then proceed to check them off. One
starts with the most likely possibilities, based upon previous
experience. That is one reason why catastrophic failure has not been
ruled out, but is considered unlikely--such a totally sudden catastrophic
failure has never been experienced with the 747 before, so it seems
unlikely. Bombs, however, have indeed caused totally sudden catastrophic
events on airplanes, including 747s--so it is therefore at the top of the
list.
This is basic logic.
D-Day
--
"Macintosh: The Power to Save the World."
Tom Simonds
timo....@tilmari.pp.fi (Timo Niroma) writes:
>>A popular theory for the crash of TWA flight 800 seems to be that it
>>was shot down using a missile (a Stinger?) from a hand-held launcher,
I think simple logic favors the sea-launched missile theory. For one
thing, if you were going to plant a bomb on a plane, you'd set it to go
off several hours into the flight. Otherwise, delays on the ground could
result in your bomb going off on the runway.
The fact that Flight 800 was attacked just after takeoff, over the water,
strongly points to a ship-launched SAM. Ground launching from NY would be
impossible. To densly populated. You'd be seen by someone. But a boat
would provide the perfect platform for launching a missile.
Even tho' investigators are leaning toward an on-board device, I vote for
the missile theory...
Jared Nedzel
In article <airliners...@ohare.Chicago.COM> Pete Mellor <p...@csr.city.ac.uk> writes:
>Andy Tompson <af...@llnl.gov> asks on Sun Jul 21 21:47:17 1996:-
>
>> I keep thinking about someone stuffing something in the landing
>> gear area while on the ground, but do we need more speculation?
>
>Perhaps not, but would someone care to comment on the following?
>
>1. It couldn't have been a bomb with a timer, since the aircraft
> was delayed on the ground for an hour before take-off, and it
> would have exploded on the runway.
I must disagree. A bomb certainly could have been timed to go
off about 1 hr., 15 min after scheduled takeoff.
>2. Exception to 1. is that a bomb with a timer was loaded at Athens,
> but with a *very* long time set to detonation. Again, that means
> that the attacker either did not care when it blew up, or set
> the timer for the mid-ocean cruise, and the delay meant that it
> exploded a few minutes after take-off.
I don't see why the bomb couldn't have been loaded at JFK. Security
at most US airports seems quite lax to me.
>3. If a bomb with a barometric detonator was loaded at New York,
> why did it not explode before 13,000 odd feet, if it was in a
> baggage hold maintained at the same pressure as the cabin,
> i.e., equivalent to 5,000 feet altitude?
Well, we don't know exactly how the cabin pressure changed on that particular
flight. In addition, a bomb could have been fused with a combination
of a barometric and timed fuse, i.e., after the cabin pressure reaches
a certain altitude, a timer is started...
>4. If it was a bomb, that (IMHO) leaves us with a barometrically
> detonated device stuffed into the landing gear or attached
> somewhere outside the pressurised cabin/baggage hold at NY
> (or perhaps a device detonated by radio signal?).
Obviously we're speculating rather wildly here, but I don't see anything
here that would make me rule out a simple timer.
--
Jared Nedzel jne...@netcom.com
MRC Partners
Just because I'm paranoid doesn't mean there isn't someone out to get me
MikeM727
In article <airliners...@ohare.Chicago.COM>, Rob Tremblay
<df...@netaccess.on.ca> writes:
>The Airbus has a safety feature that only allows a pilot to pull the
>maximum g-limit of the airplane- no more. Why would you want to
>overstress the airframe?
What if a situation arises where the only way out requires overstressing
the airplane? This could be recovery from unusual attitudes, or evasive
action to avoid traffic or terrain. There have been accidents where the
the airframe was overstressed in order to recover. For certification, the
airframe must withstand 150% of published G-limits without failure.
Someday that extra 50% percent may be needed. From what I've read, Airbus
FBW doesn't give you that option, even in direct law. I don't know about
Boeing's FBW.
Mike,
ATP/FE, Boeing 727
************************
Props are for boats!
************************
Robert Dorsett
In article <airliners...@ohare.Chicago.COM> wayn...@gwis2.circ.gwu.edu (Dwayne Allen Day) writes:
>experience. That is one reason why catastrophic failure has not been
>ruled out, but is considered unlikely--such a totally sudden catastrophic
>failure has never been experienced with the 747 before, so it seems
>unlikely.
- JAL 747-SR aft bulkhead failure.
- Iranian Imperial Air Force wing loss following lightning strike
- El Al multiple catastrophic engine failure and subsequent damage causing
severe control problems.
I'm only familiar with three accidents in which bombings have caused a jet
transport to crash: a TWA 707 over the Ionian Sea in the early 1970s; the
Pan Am crash; the Air India 747 over the Atlantic which nobody talks about.
There have many, many instances in which airplanes have been
blown up on the ground in an act of petulance (once the media accomodates
by setting up its cameras, of course :-)).
Now, if the crash investigation starts to focus on its job rather than
play media games, perhaps we'll eventually come up with an answer to *this*
one. Does anyone else find it incomprehensible that, with the likelihood a
bomber is on the loose, body recovery is being made the #1 priority of the
investigation team, apparently in a concession to media pressure, opportun-
istic politicians, and grieving victims' families?
I originally got the impression this was for forensic reasons, but the
combination of statements from the NTSB and third parties over the last
two days seems to suggest that they're under extreme pressure to do it for
humanitarian reasons.
All I'll note is that if it happened once, it could happen again. The
third parties should butt out and let the NTSB and FBI do their jobs,
unfettered.
--
Robert Dorsett Moderator, sci.aeronautics.simulation
r...@netcom.com aero-si...@wilbur.pr.erau.edu
ftp://wilbur.pr.erau.edu/pub/av
Don Stokes
In article <airliners...@ohare.chicago.com>,
doug wakefield <wake...@access4.digex.net> wrote:
>Timo Niroma (timo....@tilmari.pp.fi) wrote:
>: point in my opinion to one direction: a meteorite.
>:
>: As NASA recently announced the amount of meteorites pouring into our
>: atmosphere is grossly underestimated.
>
>Just an additional statistic, According to Author Ken Davis, the Chances
>of getting in a car accident are 100 to one, in a plane accident 20
>thousand to one, being hit by a meteor 7 thousand to one. People do die
>in plane crashes enough so people worry about flying, maybe the meteorite
>idea should be taken a little more seriously.
As far as I am aware, most if not all recent meteorite victims have lived
to tell the tale. People do occasionally get hit by meteories, and what
happens most of the time is that it hurts a bit.
A meteorite of the 7000-to-one variety hits the ground at maybe 100mph,
if that (what _is_ the terminal velocity of a small stone?), and at at
temperature often below the boiling point of water (since the merotite
ablates leaving the hot part in the atmosphere and the body of the rock
fairly cool).
A 7000-to-one meterite hitting an airliner will simply bounce off. It
would have to be a several-million-to-one meteorite to have any chance of
doing any damage.
Karl Swartz
Robert Dorsett writes:
>>experience. That is one reason why catastrophic failure has not been
>>ruled out, but is considered unlikely--such a totally sudden catastrophic
>>failure has never been experienced with the 747 before, so it seems
>>unlikely.
>- JAL 747-SR aft bulkhead failure.
>- Iranian Imperial Air Force wing loss following lightning strike
Was this the one in 1976, near Madrid? (Coincidentally, one of the
former TWA planes.)
>- El Al multiple catastrophic engine failure and subsequent damage causing
> severe control problems.
If you're going to mention this one, you should also mention the
similar China Air 747-200F crash in November 1993, not long after
departure from Taipei.
However, I think the key difference here is that none of these, with
the possible exception of the Iranian Air Force accident, produced a
sudden, catastrophic failure of the aircraft. The JAL plane flew for
the better part of an hour after the initial failure, El Al flew for
at least a few minutes, and I suspect China Air did as well, with some
reporting from the pilots of what was going on. There was not the
near-instantaneous failure evident in the case of TWA 800.
C. Marin Faure
In article <airliners...@ohare.Chicago.COM>, mike...@aol.com
(MikeM727) wrote:
> In article <airliners...@ohare.Chicago.COM>, Rob Tremblay
> <df...@netaccess.on.ca> writes:
>
> >The Airbus has a safety feature that only allows a pilot to pull the
> >maximum g-limit of the airplane- no more. Why would you want to
> >overstress the airframe?
>
> What if a situation arises where the only way out requires overstressing
> the airplane? This could be recovery from unusual attitudes, or evasive
> action to avoid traffic or terrain. There have been accidents where the
> the airframe was overstressed in order to recover. For certification, the
> airframe must withstand 150% of published G-limits without failure.
> Someday that extra 50% percent may be needed. From what I've read, Airbus
> FBW doesn't give you that option, even in direct law. I don't know about
> Boeing's FBW.
The Boeing control (cable or fly-by-whire) philosophy is to give the
pilots the ability to do anything they want with the airplane whenever
they want. The system will warn them when they approach the limits of
approved operation, and it will make it difficult to exceed these limits
(higher stick pressures, loud horns, verbal alerts, flashing lights, etc.)
but the pilots of Boeing airplanes CAN exceed the limits if they deem it
is necessary to ensure the safety of the airplane.
C. Marin Faure
author, Flying a Floatplane
don shifris
In article <airliners...@ohare.Chicago.COM>, mike...@aol.com says...
>
>In article <airliners...@ohare.Chicago.COM>, Rob Tremblay
><df...@netaccess.on.ca> writes:
>
>>The Airbus has a safety feature that only allows a pilot to pull the
>>maximum g-limit of the airplane- no more. Why would you want to
>>overstress the airframe?
>
>What if a situation arises where the only way out requires overstressing
>the airplane? This could be recovery from unusual attitudes, or evasive
>action to avoid traffic or terrain. There have been accidents where the
>the airframe was overstressed in order to recover. For certification, the
>airframe must withstand 150% of published G-limits without failure.
>Someday that extra 50% percent may be needed. From what I've read, Airbus
>FBW doesn't give you that option, even in direct law. I don't know about
>Boeing's FBW.
>
ultiimtely responsible, we better make sure he has ultimate responsibility.
The problems with current situation are pretty well understood. Airbus
airplanes have this nasty habit of second guessing the pilot at very
inopportune times. I suggest you take a good look at the post accident
investigation for the LH A320 that was destroyed on landing at Warsaw. On an
aircraft that didn't second guess the pilot, that landing would have been a
total non-event. Instead the aircraft thought it knew better, and would not
allow the spoilers, reverse thrust, or brakes to be applied because the
aircraft doesn't have enough weight on the gear. Aircraft ends up going right
off the end of the runway and is destroyed. Given the choice between a
guaranteed fatal accident, and possibly overstressing the airframe, I think
most of us would pick the overstressing the airframe. If you overstress the
airframe, the aircraft might crash. If you don't, you are certainly to crash.
That is an easy judgment call.
My other concern is over 'bugs' in this stuff. I have worked in the computer
industry for a long time. People are taught to solve specific problems in
specific ways. The Airbus approach is to use seperate teams, and seperate
hardware to insure this doesn't happen. The problem is that since these people
tend to be educated the same way, they tend to solve the problem the same way,
so it is very likely that the same, possibly bad, underlying assumption were
used in all solutions. I produced a disk driver for a super minicomputer to
address a specific problem. The manufacturer also produced a disk driver to
solve the same problem. Anyone who looked at the resultant machine code would
have concluded that the same person wrote both. I never did find out who wrote
their version, but I never communicated with him. Food for thought.
My opinions anyway
David Weeks
From what I've read, Airbus
>FBW doesn't give you that option, even in direct law. I don't know about
>Boeing's FBW.
When you are in direct law in the A320, you are talking directly to the
control surfaces, and the normal and alternate law protections are gone.
You can loop, roll, and spin to your heart's delight...
David Weeks
HP A320 captain
Stefano Pagiola
Robert Dorsett wrote:
> I'm only familiar with three accidents in which bombings have caused a jet
> transport to crash: a TWA 707 over the Ionian Sea in the early 1970s; the
> Pan Am crash; the Air India 747 over the Atlantic which nobody talks about.
Then there's the UTA DC-10 over Africa, the Korean 707 over Burma, a Cathay
Pacific CV-880 over Viet-Nam, ... and others which I'd have to check my sources
on first. (And BTW, almost every longish article I've seen on the TWA bomb
theory does mention the Air India 747.)
> Does anyone else find it incomprehensible that, with the likelihood a
> bomber is on the loose, body recovery is being made the #1 priority of the
> investigation team, apparently in a concession to media pressure, opportun-
> istic politicians, and grieving victims' families?
Incomprehensible? No. In fact, you just explained it. Dumb? Yes.
Stefano
Karl Swartz
Francis Jambon replied to Don Shifris:
>Airbus use a very clever way (IMO) to solve this. Each (of three) FBW
>computer are made of two computers of differents architectures : one with
a Motorola (68000 maybe), the other one with an Intel (8086 or 8088 ?).
>The two parts of the computers are made by differents teams and, to avoid
>communication between the teams, different manufacturers : Thomson and
>Sextant.
You seem to have entirely missed the point of the article to which you
were replying, the key point of which is contained in the following
sentence from Don's article:
The problem is that since these people tend to be educated the
same way, they tend to solve the problem the same way, so it is
very likely that the same, possibly bad, underlying assumption
were used in all solutions.
N.L. Schryer (then of AT&T Bell Laboratories) gave an Invited Talk at
the 1992 Summer Usenix in San Antonio, titled A Case Study in Testing:
Floating-point Arithmetic. It provided many excellent examples of
cases in which surprisingly different designs exhibited similar modes
of failure. (This in allegedly well-tested designs, no less!) For
example, machines as varied as the Apple ][ Plus and the Cyber 205
exhibit Really Bad Precision for some seemingly simple cases. In
another case, implementing "if (x<y)" as "if ((x-y)<0)" appears to be
innocuous enough, yet without care causes very small numbers that are
close together (but not identical) to be declared equal. Computers
from the Cray 1 to the desktop HP 9836 were found to suffer this flaw.
While his talk did not provide any specific examples of common errors
in the Motorola 68000 family and Intel 8086 family, the engineers who
designed those processors likely have at least as much common back-
ground as those who designed the Apple ][ Plus and the Cyber 205, and
thus might have unintentionally designed some similar failure modes
into the two processors.
Far from being clever, the Airbus approach foolishly fosters a false
sense of security.
For what it's worth, on the 777, Boeing started off with a similar
strategy, but ended up abandoning both hardware and software diver-
sity. Instead of spending several times as much money to support
several development efforts, they spent the money saved on doing more
rigorous review and testing of the software. It remains to be seen
whether the result was better, worse, or just different, but at least
they didn't bet on an illusion of diversity.
Francis JAMBON
In article (Dans l'article) <airliners...@ohare.Chicago.COM>,
d...@firstsol.com (don shifris) wrote (crivait):
>My other concern is over 'bugs' in this stuff. I have worked in the
>computer industry for a long time. People are taught to solve specific
>problems in specific ways. The Airbus approach is to use seperate teams,
>and seperate hardware to insure this doesn't happen. The problem is that
>since these people tend to be educated the same way, they tend to solve
>the problem the same way, so it is very likely that the same, possibly
>bad, underlying assumption were used in all solutions. I produced a disk
>driver for a super minicomputer to address a specific problem. The
>manufacturer also produced a disk driver to solve the same problem. Anyone
>who looked at the resultant machine code would have concluded that the
>same person wrote both. I never did find out who wrote their version, but
>I never communicated with him. Food for thought.
Airbus use a very clever way (IMO) to solve this. Each (of three) FBW
computer are made of two computers of differents architectures : one with
a Motorola (68000 maybe), the other one with an Intel (8086 or 8088 ?).
The two parts of the computers are made by differents teams and, to avoid
communication between the teams, different manufacturers : Thomson and
Sextant.
For the software I do not remember, but I think that they have used the
same principe, the two softwares use different languages, different teams,
different manufacturers.
What airbus wants to avoid is "common failures" on the two computers, on
the same time. These method are not used by all manufacturers, for example
the fighter Rafale build bay Dassault have two identical computer with
identical software for performance. They use formal specification and some
proofs to made them. Never forget that in a fighter you may use the
ejectable seat :-)
Francis JAMBON
--
Equipe Ingenierie des Interfaces Homme-Machine Tel : (+33) 76 63 59 70
Human-Computer Interfaces Engineering Group Fax : (+33) 76 44 66 75
E-mail: Francis...@imag.fr - URL: http://clips.imag.fr/iihm/francis.jambon/
___________ CLIPS-IMAG, B203, BP 53, 38041 Grenoble cedex 9, France ___________
Don Stokes
In article <airliners...@ohare.chicago.com>,
Francis JAMBON <Francis...@imag.fr> wrote:
>In article (Dans l'article) <airliners...@ohare.Chicago.COM>,
>d...@firstsol.com (don shifris) wrote (crivait):
>
>>My other concern is over 'bugs' in this stuff. I have worked in the
>>computer industry for a long time. People are taught to solve specific
>>problems in specific ways. The Airbus approach is to use seperate teams,
>>and seperate hardware to insure this doesn't happen. The problem is that
>>since these people tend to be educated the same way, they tend to solve
>>the problem the same way, so it is very likely that the same, possibly
>>bad, underlying assumption were used in all solutions.
>Airbus use a very clever way (IMO) to solve this. Each (of three) FBW
>computer are made of two computers of differents architectures : one with
>a Motorola (68000 maybe), the other one with an Intel (8086 or 8088 ?).
>The two parts of the computers are made by differents teams and, to avoid
>communication between the teams, different manufacturers : Thomson and
>Sextant.
The point remains. Heck, I use the _same_ code on different computers
with different architectures and even different operating systems, with
only minor if any changes -- the differences in the systems doesn't
change the picture much at all. Even using different languages, one can
use the same algorithms. What using different architectures means is
that you're unlikely to get the same erroneous sequence of instructions
from some common compiler bug cropping up, but little better than that.
Somewhere in my cookie file is the quote:
For every complex problem, there is a solution that is simple,
elegant, and wrong.
As long as you are trying to achieve the same thing, you're going to have
to use, out of necessity, use the same or at least similar algorithms,
and two people can jump to the same erroneous conclusion.
I'm not saying that the multiple systems approach is invalid. I am
saying that one should _not_ rely on it alone to produce correct code.
Formal methods should _also_ be used.
>the same time. These method are not used by all manufacturers, for example
>the fighter Rafale build bay Dassault have two identical computer with
>identical software for performance. They use formal specification and some
>proofs to made them. Never forget that in a fighter you may use the
>ejectable seat :-)
You _don't_ want to use the ejection seat. An ejection seat is something
that you use when faced with the prospect of certain death if you remain
with the aircraft, as opposed to probable death if you bail out. They're
fitted into combat aircraft simply because flying a combat aircraft is
_dangerous_ -- in combat you have human beings actively out to destroy
your craft, something commercial pilots generally don't have to deal
with. The nature of making an aircraft maneuverable enough for combat
also makes it more susceptible to failure. For example, fighters and
small bombers glide like bricks whereas any commercial transport can be
safely deadsticked to a landing (given a suitable site and a certain
amount of luck).
Jay Blosser
Karl Swartz wrote:
>
> --- snip ----
>
> For what it's worth, on the 777, Boeing started off with a similar
> strategy, but ended up abandoning both hardware and software diver-
> sity. Instead of spending several times as much money to support
> several development efforts, they spent the money saved on doing more
> rigorous review and testing of the software. It remains to be seen
> whether the result was better, worse, or just different, but at least
> they didn't bet on an illusion of diversity.
I may be wrong, but I'm under the impression that the 777 Primary Flight
Computers employ three different CPU's per channel (68040, 80486, ???) but
all are programmed in the same high-level language (Ada ?). Rumor has it
that Boeing backed out of dis-similar software in the PFC when they saw
its expense and realized the marginal effectiveness of the generic fault
immunity that it provided.
Jay Blosser All opinions are my own and are not intended
to reflect those of others, including my employer.
Neil Bolger
MikeM727 wrote:
> >The Airbus has a safety feature that only allows a pilot to pull the
> >maximum g-limit of the airplane- no more. Why would you want to
> >overstress the airframe?
>
> What if a situation arises where the only way out requires overstressing
> the airplane? This could be recovery from unusual attitudes, or evasive
> action to avoid traffic or terrain. There have been accidents where the
> the airframe was overstressed in order to recover. For certification, the
> airframe must withstand 150% of published G-limits without failure.
> FBW doesn't give you that option, even in direct law. I don't know about
> Boeing's FBW.
What about a stall? Do you ever want to stall a large commercial
airliner other than during initial flight tests? I would think it
would be highly beneficial to never be able to stall a plane but to go
right to the maximum angle of attack, and to have the computer advance
the throttles, etc. What do you experienced people have to say about
this? Are there any other situations where you would always want the
computer to stop you?
Neil Bolger
http://www2.portal.ca/~urbanpre/airneil.html
Joachim Achtzehnter
In article <airliners...@ohare.Chicago.COM>,
Karl Swartz <k...@ohare.Chicago.COM> wrote:
> Francis Jambon replied to Don Shifris:
>
> > Airbus use a very clever way...
> > made of two computers of different architectures...
> > made by differents teams...
> > different manufacturers...
>
> You seem to have entirely missed the point...
>
> Far from being clever, the Airbus approach foolishly fosters a false
> sense of security.
>
> Boeing ... they spent the money saved on doing more
> rigorous review and testing of the software... but at least
> they didn't bet on an illusion of diversity.
This discussion would benefit if people dropped their respective biases
for or against Boeing/Airbus and US versus European aircraft manufacturers.
The real point is that a sensible approach to fault tolerance does both:
Use rigorous control over design and implementation with extensive test
programs, and try to limit common failure modes of redundant parts of the
system.
Using different people to build the redundant parts certainly REDUCES the
likelihood of common failure modes. I don't think anybody would claim
otherwise.
In terms of "illusion": both approaches can result in complacency if one isn't
careful. Neither rigorous control nor redundancy can guarantee 100% safety.
Both are useful to improve safety. So rather than jump on people with phrases
like "missing the point", "foolishly", etc. lets foster the open discussion of
diverse approaches to achieve safety.
Joachim
--
joa...@softouch.bc.ca (work)
joa...@wimsey.ca (home)
Karl Swartz
>This discussion would benefit if people dropped their respective biases
>for or against Boeing/Airbus and US versus European aircraft manufacturers.
Why is it that whenever anyone says anything that might in any way be
taken as negative to Airbus, all the Airbus fanatics start jumping up
and down about "US vs Europe?" This seems to happen even with both
Airbus and McDonnell-Douglas are compared to Boeing -- I guess MacDAC
must be European and not US.
"Methinks the lady doth protest too much."
>The real point is that a sensible approach to fault tolerance does both:
>Use rigorous control over design and implementation with extensive test
>programs, and try to limit common failure modes of redundant parts of the
>system.
>Using different people to build the redundant parts certainly REDUCES the
>likelihood of common failure modes. I don't think anybody would claim
>otherwise.
Unfortunately, we do not live in a theoretical world devoid of costs.
Doing so costs roughly twice as much, yet it's not clear that there is
a *substantial* reduction in common failure modes. Indeed, the higher
complexity may result in a net loss in reliability of the system.
James Horan
MikeM727 wrote:
> >The Airbus has a safety feature that only allows a pilot to pull the
> >maximum g-limit of the airplane- no more. Why would you want to
> >overstress the airframe?
>
> What if a situation arises where the only way out requires overstressing
> the airplane? This could be recovery from unusual attitudes, or evasive
> action to avoid traffic or terrain. There have been accidents where the
> the airframe was overstressed in order to recover. For certification, the
> airframe must withstand 150% of published G-limits without failure.
> Someday that extra 50% percent may be needed. From what I've read, Airbus
> FBW doesn't give you that option, even in direct law. I don't know about
> Boeing's FBW.
I would certainly guess that there is a more that 50% extra in a lot of
areas. I recall one old job shop engineer that I worked with who was
looking at some wreckage from a B-1. He said that he thought that anything
that was left together after a crash was overdesigned because planes are
made to fly not crash. Time and time again aircraft are subjected to much
higher loads than any designer anticipated and they held up. I recall a
B-52G back in the mid-80's when I was at Boeing Wichita that had a vertical
fin blown off by a gust that was approximately 5 times the Mil-Spec load.
It probably failed at around 3x.
Also remember there are two sets of loads yield and ultimate. You may bend
the aircraft but not break it. I would much rather land on a bent aircraft
that is no longer airworthy then crash on an airplane that would be
otherwise flight worthy but for the fact that it smacked into the ground.
James P. Horan, Esq.
Staten Island, NY
Jean-Francois Mezei
You can argue all you want about whether having multiple different
systems cross check each other, or having identical systems cross check
each other.
But judging from what I have learned about the Airbus problems, many of
the problems did not occur because of coding errors, they occured
because of design errors (for instance checking for both squat switch
AND wheels turning before allowing deployment of thrust reversers which
caused a problem landing on a wet runway when wheels would skid and not
turn).
However, many of the problems were caused by computer flaws, notably
with the alarm computers who generated many false alarms which resulted
in the plane taking immediate corrective actions (confusing pilots).
There were also cases of the adjustment of the cabin temperature
affecting the engine thrust routines during a flight.
With identical inputs and outputs, different programs can only differ so
much. And if different systems are fed with the same erroneous data, the
different systems will respond with erroneous outputs.
I beleive that the different systems do have the following advantage:
In the event of special yet-untested conditions arising that cause one
computer system to crash, having different programs will reduce the
likelyhood that all systems will crash (eg: division by zero, trying to
access non-existant memory etc).
As far as over-automation and imposed limits:
Do you not think that the designers of the DC-3 imposed limits when they
designed the rudders and elevators and decided just as much they could
physically move ?
Do you not think that the designers of new engines imposed limits when
they added electronic fuel controls ?
The argument that one should be allowed to "bend" the aircraft and cheat
the limits in order to save the flight is made MANY MANY times. While I
am sure that many examples can be brought up where such "cheating" saved
lifes. However, I wonder if there are many RECENT proofs on RECENT
aircrafts.
Newer and lighter materials and alloys may not have that "bending"
ability that older materials have, so claiming that it is safe to "bend"
a A320 is not necessarily true even though it might be true for a
similar claim for a vintage 727 or 737-200.
Gary Neff
In article <airliners...@ohare.Chicago.COM>, "http://www2.portal.ca/~urbanpre/airneil.html"@thoth.portal.ca wrote:
>What about a stall? Do you ever want to stall a large commercial
>airliner other than during initial flight tests? I would think it
>would be highly beneficial to never be able to stall a plane but to go
>right to the maximum angle of attack, and to have the computer advance
>the throttles, etc. What do you experienced people have to say about
>this? Are there any other situations where you would always want the
>computer to stop you?
I can't even begin to imagine a situation, in any phase of flight, where you'd
get close to a stall (except windshear training in the sim, perhaps), in a
transport catagory aircraft.
Gary