KC-767 ????

In article , Pooh Bear rabbitsfriendsand
writes
Wasn't it this accident that led to the floor lighting for evacuation ?

Yes, and also the water mist system trials which seemed very successful
in improving cabin survivability.

Very definitely it raised the question of smoke hoods. To this day the CAA /
FAA insist on flotation collars in the event of downing in water - as if the
a/c would survive intact, yet deny the usefulness of smoke hoods. Curious
priorities.

The smoke hood reasons were mainly that they'd prefer passengers to
concentrate evacuating the aircraft rather than trying to put on smoke
hoods in the time available. Other problems were foreseen, basically
that the hoods would disappear from the aircraft after the flight as
passengers realised they'd help in hotel fires as well. Not only does
this add cost (replacing them all), but in a situation where some
passengers had hoods and some didn't, fighting may break out for those
that were available.

--
John

"M22315" writes:

And was not 191 found survivable if not for the slats issue?

Not really. One of the major conclusions in the report was that three major
factors contributed to the loss of control/crash following pylon separation:
"the retraction of the left wing's outboard leading edge slats; the loss of
the slat diagreement warning system; and the loss of the stall warning
system --all resulting from the separation of the engine pylong assembly.
Each by itself would not have caused a qualified flight crew to lose control
of its aircraft, but together during a critical portion of [flight], they
created a situation which afforded the flight crew an inadequate opportunity
to recognize and prevent the ensuing stall of the aircraft." p. 55 NTSB
Final Report AAR79-17.

Maybe I'm reading that differently, but that seems to indict the slats system
to me!

I recall something about the stall warning. Was it that it was not
on the emergency power bus? Or that there was only one with no
backup...?

A old cow orker assembled L-1011's (I believe that was contemporaneously
with 191 but it's been a while...) and his comment was:

{They} [i.e. L1011 &747] cost roughly $10 million more than
the DC-10 -- what did Mac-D leave out that Boeing and Lockheed
didn't?

From memory, each had more redundancy in hydraulics/pneumatics than the -10.

--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

"David Lesher" wrote in message
...
"M22315" writes:

And was not 191 found survivable if not for the slats issue?

Not really. One of the major conclusions in the report was that three
major
factors contributed to the loss of control/crash following pylon
separation:
"the retraction of the left wing's outboard leading edge slats; the loss
of
the slat diagreement warning system; and the loss of the stall warning
system --all resulting from the separation of the engine pylong assembly.
Each by itself would not have caused a qualified flight crew to lose
control
of its aircraft, but together during a critical portion of [flight], they
created a situation which afforded the flight crew an inadequate
opportunity
to recognize and prevent the ensuing stall of the aircraft." p. 55 NTSB
Final Report AAR79-17.

Maybe I'm reading that differently, but that seems to indict the slats
system
to me!


As one of several factors. Go back to the source of the chain of
events - the engine pylon loss due to poor maintenance practices. Without
the poor maintenance practices, the pylon doesn't come off. If the pylon
doesn't come off, the hydraulics don't rupture, allowing the slats to remain
extended. Additionally, if the pylon doesn't come off, you don't lose the
generator powering the slats disagree and the stall warning system (the loss
of slats changed the stall speed for the outboard portion of the wing).
Calling the slats failure the reason the plane went down is greatly
overstating it. Poor maintenance procedures, leading to the loss of the
engine and the subsequent cascade of systemic failures (possibly related to
a vulnerable design), led to the crash. In theory, pilots who understood
clearly the sequence of events in the crash and who had stall warning
available to them in the simulator were able to save the aircraft.

I recall something about the stall warning. Was it that it was not
on the emergency power bus? Or that there was only one with no
backup...?

Considering the rapid series of multi-systemic failures that followed
the loss of the engine, the flight engineer and pilots had their hands full
trying to assess the scope of the situation and the appropriate response.
As it happens, the pilots followed the engine out procedures from American
(climb at V2), however, the V2 speed was below the stall speed of the
outboard wing after the slats retracted.


A old cow orker assembled L-1011's (I believe that was contemporaneously
with 191 but it's been a while...) and his comment was:

{They} [i.e. L1011 &747] cost roughly $10 million more than
the DC-10 -- what did Mac-D leave out that Boeing and Lockheed
didn't?


I would expect the 747 to cost somewhat more than the DC-10. The L-1011, I
would expect to cost the same. Of course, it could come down to economies
of scale. If at the time McD had a more robust aircraft manufacturing base
than did Lockheed (as I recall, Lockheed was making pretty much just the
L-1011 as a commercial aircraft in addition to its military aircraft), then
McD could take less money per plane than Lockheed. As I recall, McD made
around twice as many DC-10s than Lockheed made L-1011s. There's economies
of scale at play there, too.


From memory, each had more redundancy in hydraulics/pneumatics than
the -10.

In article ,
Pooh Bear wrote:

Larry Doering wrote:

The revised probable cause was that a faulty switch or a wiring
problem had caused the electrically actuated door latches to move
partway towards the unlatched position after the door was closed
but before takeoff.

Interesting. Thanks for that Larry.

So that means the position indicators that were post-installed to be checked by
ground crews weren't the answer ?

Dunno about that.

Dare I say this ? but some ppl have suggested this / similar cause for TWA 800
too !

If you're referring to John Barry Smith's website at www.corazon.com,
he seems to believe that failure of the forward cargo door was the
cause of the loss of both TWA 800 and Air India 182. Problem is,
there's no evidence of a cargo door failure in the wreckage of TWA
800 (and plenty of evidence of a fuel-air explosion in the aicraft's
center fuel tank), and there is conclusive evidence that Air India
182 was destroyed by a bomb.

Deteriorating wiring is thought to have been the most likely ignition
source for the explosion that brought down TWA 800, but the forward
cargo door was found with other fuselage wreckage and its latches
were intact and in the closed position.

Didn't realise that the wiring prob had been *officially* recognised in
the way you mention. I've seen an interesting example of wire bundle fraying
myself as it happens ( auto not a/c - but surprised me ) .

As I understand it, an electrical problem was thought to be the
cause based on examination of United 813's cargo door (the latches
were attached to the door, so were not available for accident
investigators to look at during the initial investigation.) I
don't believe investigators actually found a "smoking gun" in the
form of deteriorated wiring or damaged electrical components.


ljd

In article ,
Pooh Bear wrote:
Larry Doering wrote:

The original NTSB report (AAR-90/01) can be found at the Embry-Riddle
Aeronautical University library web site at:

http://amelia.db.erau.edu/reports/nt.../AAR-90-01.pdf

and the 1992 report which supersedes AAR-90/01 at:

http://amelia.db.erau.edu/reports/nt.../AAR-92-02.pdf

They seem to be dead links. Can you assist ?

Whoops, the filenames on the website don't contain the first hyphen.

http://amelia.db.erau.edu/reports/ntsb/aar will get you a
directory listing, and the files are AAR90-01.pdf and AAR92-02.pdf.


ljd

In article ,
Ron Parsons wrote:
In article ,
(Larry Doering) wrote:

Every account I've seen blames this on the cargo door latch mechanism,
not on shifting cargo. It's true that a casket that was in the cargo
compartment went out the rear door as the aircraft depressurized, but
that wasn't the cause.

The latch design and poor quality control were the causes. The slight
bump from the shifting coffin was simply the last straw.

Do you have a source for this detail? Like I said, none of the
material I've seen regarding this incident claims that loose
cargo was the cause of the cargo door failure.


ljd

"Mary Shafer" wrote

Give me a break. They were changing engines with a _forklift_.
Design is not the issue. Inappropriate maintenance procedures are.

Considering that a forklift was used to raise and lower the engine and
pylon, I don't think design is much of an issue. I've never seen a
calibrated forklift. Nor have I seen one that was so precise it could
be used in spaces with tight tolerances.

Compare a standard forklift with a bomb lift truck or trailer. The MJ-1 and
MHU-83 used on fighters, or the MHU-123 and -173 trailers used on B-52's.
Really, just long, low forklifts. None 'calibrated'. Just levers to actuate
the hydraulics, or a remote control for the -173.

Installation of a pivot pylon on the F-111, using an MJ-1. No one would ever
call a jammer a calibrated item, yet the install clearances on the pylon are
sub 1/4". Same with weapons, and preloaded pylons. Very close tolerances.
With lift trucks that have notoriously sloppy controls.

With an experienced operator, they can be quite precise. With a hamhanded
fool...any tool is dangerous.

The forklift may not have been the approved, tested item. But with a
reasonable operator, using a forklift would be no different than any other
lift tool.

Pete

Pete wrote:

snip

Compare a standard forklift with a bomb lift truck or trailer. The MJ-1 and
MHU-83 used on fighters, or the MHU-123 and -173 trailers used on B-52's.
Really, just long, low forklifts. None 'calibrated'. Just levers to actuate
the hydraulics, or a remote control for the -173.

Installation of a pivot pylon on the F-111, using an MJ-1. No one would ever
call a jammer a calibrated item, yet the install clearances on the pylon are
sub 1/4". Same with weapons, and preloaded pylons. Very close tolerances.
With lift trucks that have notoriously sloppy controls.

With an experienced operator, they can be quite precise. With a hamhanded
fool...any tool is dangerous.

The forklift may not have been the approved, tested item. But with a
reasonable operator, using a forklift would be no different than any other
lift tool.

Depends on the forklift, too. Some are easy to make very precise adjustments
with. Others are almost hopeless (raising; lowering is rarely a a problem,
although really stiff controls can make even lowering an on/off, jerky event).

Guy

In article ,
(Larry Doering) wrote:

In article ,
Ron Parsons wrote:
In article ,
(Larry Doering) wrote:

Every account I've seen blames this on the cargo door latch mechanism,
not on shifting cargo. It's true that a casket that was in the cargo
compartment went out the rear door as the aircraft depressurized, but
that wasn't the cause.

The latch design and poor quality control were the causes. The slight
bump from the shifting coffin was simply the last straw.

Do you have a source for this detail? Like I said, none of the
material I've seen regarding this incident claims that loose
cargo was the cause of the cargo door failure.

No source that you can check. Just in-house conversations and briefings
at the time.

--
Ron

Give me a break. They were changing engines with a _forklift_.
Design is not the issue. Inappropriate maintenance procedures are.

Considering that a forklift was used to raise and lower the engine and
pylon, I don't think design is much of an issue. I've never seen a
calibrated forklift. Nor have I seen one that was so precise it could
be used in spaces with tight tolerances.

We always removed and installed our engines on special engine carts,
not forklifts. The USAF and USN used the engine carts, not forklifts,
too. And Lockheed didn't use forklifts to change out L-1011 engines,
either.

As the corollary to Capt. Murphy's Law tells us: "Build something
that's foolproof and a bigger fool will come along."

Mary

--
Mary Shafer FIRED aerospace research engineer



Give me a break I specifically said that statement was from a engineering
website!!!!


http://www.tsgc.utexas.edu/archive/g...s/aacrash.html