Catastrophic Decompression; Small Place Solo

In the pressure chamber,
from 25000 to sea level is instantaneous and you do a sustained
burp-and-fart.

Bob Gardner

Other way around Bob. (sea level to 25,000)

The preasure is not going to drop to ambient in an airliner unless there is
a HUGE hole. The combined outflow valve area on an airliner is probably
bigger that the area of a cabin window, maybe several windows. As soon as
the preasure starts dropping, the valves are going to start closing. There
may not even be a loss of preasurization

Mike
MU-2


"G.R. Patterson III" wrote in message
...


Aviation wrote:

On the one hand, passengers need to get denser air to breathe
but large aircraft have oxygen masks that drop down.

If the aircraft is much above 25,000', the masks will do little good. You
need
a pressure mask to survive long at (for example) 35,000'. Those used by
the
airlines for passengers are not good enough for that.

(I could
do some rough estimates that the average fat slob can hold
their breath for less than a minute so, without masks, the jet
would have to go from let's say 30000 feet to 5000 feet in
30-45 seconds. My ears would explode.)

Nobody can hold their breath in that situation - the pressure difference
will
cause you to exhale. Above about 25,000', the air pressure is low enough
that
oxygen actually passes backwards out of your bloodstream into the lungs
and out
of the body. As for your ears, they're already toast. The pressure just
dropped
from the pressure at 8,000' to that at cruise altitude in a few seconds.

Basically, the pilots need to get their masks on and get the plane down
below
25,000' as rapidly as it can possibly be done. The descent to 10,000' can
be made
a little more leisurely, but not much - there's always someone in the
cattle
section who panicked and isn't wearing a mask. If that's one of the flight
attendants, you're really in trouble.

have to do it again just because the instructor's getting out.

George Patterson
Great discoveries are not announced with "Eureka!". What's usually
said is
"Hummmmm... That's interesting...."

"G.R. Patterson III" wrote in message
...


Aviation wrote:

On the one hand, passengers need to get denser air to breathe
but large aircraft have oxygen masks that drop down.

If the aircraft is much above 25,000', the masks will do little good. You
need
a pressure mask to survive long at (for example) 35,000'. Those used by
the
airlines for passengers are not good enough for that.

(I could
do some rough estimates that the average fat slob can hold
their breath for less than a minute so, without masks, the jet
would have to go from let's say 30000 feet to 5000 feet in
30-45 seconds. My ears would explode.)

Nobody can hold their breath in that situation - the pressure difference
will
cause you to exhale. Above about 25,000', the air pressure is low enough
that
oxygen actually passes backwards out of your bloodstream into the lungs
and out
of the body. As for your ears, they're already toast. The pressure just
dropped
from the pressure at 8,000' to that at cruise altitude in a few seconds.

Agreed

Basically, the pilots need to get their masks on and get the plane down
below
25,000' as rapidly as it can possibly be done. The descent to 10,000' can
be made
a little more leisurely, but not much - there's always someone in the
cattle
section who panicked and isn't wearing a mask. If that's one of the flight
attendants, you're really in trouble.

Agreed.

There is 1 further issue not yet addressed. Ambient Temp at altitude.
Ambient temps of -30 degrees F or lower are not uncommon at altitudes
25,000 ASL.

Decompression, explosive or otherwise, results in a significant drop in
cabin Temp resulting in ~ fairly rapid freezing.

There have been any number of documented incidents, military & civilian,
over the years where an A/C lost pressure at altitude, disabling the crew,
with the A/C continuing on "Auto Pilot", crashing when fuel exhausted. It is
routine for A/C in this situation to be intercepted/followed/kept under
surveillance/filmed by military A/C. The most recent "Widely/Highly
Publicized Example"of this was the "Payne Stewart" incident.
Ralph Nesbitt
Professional FD/CFR/ARFF Type

The FAA has opportunities for a chamber ride to actually experience rapid
decompression, and we have to do it periodically in the Air Force while on
flying status. On of our classmates volunteered to take off his oxygen mask
at 25,000 feet. He turned green immediately and started seizing, and despite
being prepared, he was unable to gang load his oxygen regulator and put his
mask back on. I wonder how many brain cells he killed.

The rapid decompression was pretty uneventful- there was kind of a loud pop,
and a lot of fog. This is the result of condensation due to cooling of the
air from expansion, not moisture from our bodies.

If you ate a lot of Mexican food the night before the pain from the gas
expanding comes on the ascent, not on the descent. Likewise, ear blocks
(feels like sticking an ice pick in your ear from personal experience) comes
during descent only, as the increased ambient pressure pushes inward on your
ear drum.

The most valuable part of the ride was the ability to recognize symptoms of
hypoxia, like decreased color vision, etc. A

Anyone who ever flies over 10,000 feet (or less at night) should consider a
chamber ride a valuable and potentially life saving experience.

Aviation wrote:

On the one hand, passengers need to get denser air to breathe
but large aircraft have oxygen masks that drop down.

If the aircraft is much above 25,000', the masks will do little good. You need
a pressure mask to survive long at (for example) 35,000'. Those used by the
airlines for passengers are not good enough for that.

(I could
do some rough estimates that the average fat slob can hold
their breath for less than a minute so, without masks, the jet
would have to go from let's say 30000 feet to 5000 feet in
30-45 seconds. My ears would explode.)

Nobody can hold their breath in that situation - the pressure difference will
cause you to exhale. Above about 25,000', the air pressure is low enough that
oxygen actually passes backwards out of your bloodstream into the lungs and out
of the body. As for your ears, they're already toast. The pressure just dropped
from the pressure at 8,000' to that at cruise altitude in a few seconds.

Basically, the pilots need to get their masks on and get the plane down below
25,000' as rapidly as it can possibly be done. The descent to 10,000' can be made
a little more leisurely, but not much - there's always someone in the cattle
section who panicked and isn't wearing a mask. If that's one of the flight
attendants, you're really in trouble.

I was wondering if taking your FIRST solo flight is that simple.

Pretty much. My instructor also told me to do three takeoffs and landings to a
full stop and park it when I was done.

The location in the film in Washington, DC but I figure all
US flying is FAA regulated. Wouldn't the first time soloist
have to fill out some forms, file a flight plan with the
airport and maybe even do a complete pre-flight check on the
aircraft?

All the forms got filled out way back when you applied for a student pilot's
licence. No flight plan is required for any VFR flight in the U.S.. The pre-flight
inspection was done before the student and instructor got in the plane - you
don't have to do it again just because the instructor's getting out.

George Patterson
Great discoveries are not announced with "Eureka!". What's usually said is
"Hummmmm... That's interesting...."

If a window blows out, everything that is not tied down will certainly be
sucked out, and this could include people if they were small enough.

Its my understanding that in an explosive decompression like this, the
decompression will happen very fast. The Goldfinger episode goes on for 45
minutes of hanging on for dear life while the plane depressurizes. My
un-educated guess is that this would happen in seconds or less.

Get the tail number and look it up...



Marco Leon wrote:
"Aviation" wrote in message
u...

The second Hollywood inspired question comes from Executive
Decision (1996). The main character is taking flying lessons
in a single prop 2-seater plane and lands. The plane is still
running (on the ground) and his instructor says, 'I think
you're ready to solo' and gets out. The main character starts
to taxi and then other non-flying plot developments happen.
I was wondering if taking your FIRST solo flight is that simple.

The location in the film in Washington, DC but I figure all
US flying is FAA regulated. Wouldn't the first time soloist
have to fill out some forms, file a flight plan with the
airport and maybe even do a complete pre-flight check on the
aircraft? Is the simplified movie solo flight completely
bogus or could it happen that way?



Yes as mentioned by others, the first solo is usually that easy (with a
couple of signatures in your logbook)

The plane in Executive Decision was a Bonanza that has 4 or 6 seats (model
F33 or A/B36 respectively. Not sure which was in the movie) and Kurt Russell
is a pilot in real life. That plane could have very well been his own Or
at least he may have been flying it during the filming. Anyone know??

Marco



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Having questions about flying in general and soloing in particular I
would like to suggest that everyone go out to your nearest local airport
and inquire into taking the introduction student flight. This is a half
hour flight under instruction and can be free at most FBO's. Check "
http://www.beapilot.com " for information.
The cost of obtaining your private pilot license is in the $3,000 to
$4,000 range. It usually takes 50 to 60 hours of instruction and flying
to qualify.

David Nagel

Geoffrey Barnes wrote:

Can't offer much help with your first question, but...


The second Hollywood inspired question comes from Executive
Decision (1996). The main character is taking flying lessons
in a single prop 2-seater plane and lands. The plane is still
running (on the ground) and his instructor says, 'I think
you're ready to solo' and gets out. The main character starts
to taxi and then other non-flying plot developments happen.
I was wondering if taking your FIRST solo flight is that simple.

The location in the film in Washington, DC but I figure all
US flying is FAA regulated. Wouldn't the first time soloist
have to fill out some forms, file a flight plan with the
airport and maybe even do a complete pre-flight check on the
aircraft? Is the simplified movie solo flight completely
bogus or could it happen that way?


The basic answer is "more or less". My first solo was more or less exactly
like that. But keep in mind that nobody solos on their first lesson, or
their third, or usually even their fifth, sixth, seventh or eighth. I had
15 sessions of dual instructruction, all with the same instructor, before he
signed me off to do my first solo.

Now, onto specifics. The first time soloist would have to hold a valid
medical certificate, and the instructor is required to have tested the
applicant on key bits of knowledge. Usually, this knowledge is tested using
an informal written examination. But other than getting the medical and
taking this test, no other forms need to be filled out, at least by the
student. The instructor has some paperwork to fill out. Specifically, the
instructor must inscribe some verbage into the student's log book, and sign
off an endorsement on the reverse side of the student's medical certificate.
So the instructor can't just verbally say, "I think you are ready", and then
climb out of the plane. Instead, the student gets a good minute or two to
contemplate their impending solo as the instructor writes things in their
book and on their certificate, and then the instructor gets out. And boy,
is it quiet all of the sudden when the instructor leaves, let me tell you!

No flight plan is required, because the first time soloist isn't really
going anywhere. The most a first time soloist is going to do is take off,
follow a rectangular path around the airport's traffic pattern, and land
(almost always on the same runway that he or she took off from).

The pre-flight wouldn't be necessary in this case, because the characters in
the movie would have alreaedy done one before the lesson began. After the
first few lessons, the student always does a preflight anyway. So in the
movie, the student would have done one prior to taking off with the
instructor onboard. By the way, the instructor has to do a few landings and
takeoffs with the student (I think it's three of each) immediately before
the first solo occurs. I'm not sure if that's part of the FARs, or just a
requirement of my FBO, but that's what he told me.

Hope this helps!

In article ,
"Ron Natalie" wrote:

"Bob Gardner" wrote in message
news:cLmIb.79193$VB2.159840@attbi_s51...
I have no direct knowledge of how big an airliner
outflow valve is, but I am going to guess three inches in diameter

I think this is a good guess. It sort of looks like the top of a can of
parmesan cheese.

Parmesan cheese comes in *cans*?! Maybe I've lived in the Bay Area too
long :-).

Hamish

"Jeff Franks" wrote in message
...

If a window blows out, everything that is not tied down will certainly
be
sucked out, and this could include people if they were small enough.

Its my understanding that in an explosive decompression like this, the
decompression will happen very fast. The Goldfinger episode goes on for
45
minutes of hanging on for dear life while the plane depressurizes. My
un-educated guess is that this would happen in seconds or less.

Witnessed the result of "Port Hole Window" on the starboard side of a C-5
blowing out during "Initial Factory Pressure checks" on a new C-5". The
window itself went through the side of a "Tin Sided Building" ~ 200' from
where the window/port hole came from. A substantial number of the
insulation/batting blankets were torn from their normal place in the cargo
bay & piled on the cargo bay floor near the opening. A large number of the
insulation blankets/bats, along with seat cushions from the upper aft troop
compartment were piled around the entrance to the stairs from the troop
compartment down to the cargo bay, plus scattered along the cargo bay floor
in the direction of the failed port hole/window. Seat cushions, mattresses
from bunks, & insulation bats/blankets from the upper front area were piled
against the exit stairs from the upper from lobe & along the cargo bay floor
toward the failed port hole/window. A few of the insulation bats/blankets
were blown out the failed port hole/window.

A/C being tested were instrumented to record/document test protocols as
appropriate. According to instrumentation on the A/C, at time of port
hole/window failure the air pressure dropped from 14.5 lbs to 0 in .003
seconds.

Factory Pressure Check on C-5's was 15 pounds, slightly over 1 atmosphere.
This was worked up to in stages. This incident occurred.
Ralph Nesbitt
Professional FD/CFR/ARFF Type