Catastrophic Decompression; Small Place Solo

On Fri, 2 Jan 2004 at 23:00:12 in message
, John Gilmer
wrote:
SIlly question but ...

Why would "they" pressurize the aircraft to sea level? Why not some
compromise "pressure" like that equivalent to, say, 6,000 or 8,000 feet?

This test, if correctly described, is irrelevant to sudden decompression
of aircraft anyway. The problem is decompression not sudden
re-compression.

In the cabin you are at, say 8,000ft. A big hole appears and you are
suddenly at the altitude the Aircraft was actually flying.
--
David CL Francis

"John Gilmer" wrote in message
...

"Mike Rapoport" wrote in message
hlink.net...

"Ralph Nesbitt" wrote in message
gy.com...

"Mike Rapoport" wrote in message
hlink.net...

"Ralph Nesbitt" wrote in message
m...
Hopefully all realize when referring to "Air Pressure" at altitude
this
is
an "absolute" pressure value inside the fuselage irrespective of
ambient.
When referring to air pressures at ground level the pressure
reading
is
above unadjusted ambient barometric pressure.

This is incorrect, pressurization is the differential between
ambient
and
cabin preasure.

Mike
MU-2

Please reconsider your statement above as it applies to pressurization
of
A/C cabins at altitude.

At altitude A/C cabins are like a pressure vessel. A/C cabins are
pressurized to maintain ~ 12 PSI Gauge, ~ the same as normal
atmospheric
pressure @ 11,000' ASL, in the cabin irrespective of altitude above
11,000'
ASL.
Ralph Nesbitt
Professional FD/CFR/ARFF Type

No, the cabin is not at a constant preasure above 11,000' (and the
number
that you are looking for is 8,000') unless the rate controller is set to
a
rate greater than the climb rate of the aircraft (which is never done).
If
what you say were true then the cabin altitude would not climb with the
airplane above 11,000' (8,000') which it clearly does. If you doubt
this,
go buy an altimeter watch and see for yourself. Or you could buy a
pressurized airplane.

OK, I'll bite.

Just how does the psia in the cabin track the psia "ambient."


What are you asking?

Mike
MU-2

"Scott M. Kozel" wrote in message
...
How could an SST like the Concorde get from cruising altitude down to
10,000 feet in 3-5 minutes?

Easy, it's called an Emergency Descent. Power to idle, spoilers/speedbrakes
deployed, maybe gear extended (depends on aircraft), then dive at redline
speed. The airplane I fly (Lear 60) it takes an initial deck angle of ~ 20
degrees nose down to obtain redline, then ~ 10-12 degrees to hold it there.

We practice it every time we have a simulator check. Never takes more than
3 mins to get from FL450 to 10,000 ft.

Mish

"Marco Leon" mleon(at)optonline.net wrote in message ...
"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


CE-421

"Marco Leon" mleon(at)optonline.net wrote in message ...
I was hoping this medium would be faster than renting the flick. Besides,
many publically accessible information regarding celebrities are ususally
cryptic. Ever seen a privately-owned plane registered under a corporation?


yup. regularly

Dr. George O. Bizzigotti wrote in message . ..
On Tue, 30 Dec 2003 19:43:55 -0800, "G.R. Patterson III"
wrote:

Aviation wrote:

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

[snip]

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.

Based on what others have written about chamber simulations, it would
appear that irreversible ear damage (which is what I would infer as
being "toast") is not an inevitable consequence, although. I've no
doubt that the sensation from any reversible consequences is not
always pleasant .

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.

One aspect that I have not seen addressed in this thread is the fact
that most oxygen systems can provide supplemental oxygen for a few
minutes only (I dimly recall figures like 3-5 minutes, but that may be
inaccurate). The pilots also need to get down to 10,000 feet within
that time before everyone's oxygen generators run out.

Regards,

nope. supplemental oxygen depends on the capacity of the resevoir, the
flow, the delivery system in use and of course the demands on this
(load) the requirements are in the FAR's.

23.1441 thru 23.1449
25.1441 thru 25.1449
121.327 thru 121.337
125.219
135.89 thru 135.91
135.157

(One's Too Many) wrote in message . com...
"Bob Gardner" wrote in message news:d0oIb.79631$VB2.161783@attbi_s51...
I just measured my Kraft 8oz container of grated Parmesan...2 3/4 inches.
Close enough?

Bob Gardner

Well, maybe close enough. That stuff in the Kraft can might qualify as
some kind of 'Parmesan-like substance', but I'd hestiate to call it
real Parmesan cheese. I'd only consider putting it on my pasta if I'd
had way too much wine to drink beforehand.


"cheese flavoured product" is the catch all there !

"Scott M. Kozel" wrote in message ...
Dr. George O. Bizzigotti wrote:

"G.R. Patterson III" wrote:

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.

One aspect that I have not seen addressed in this thread is the fact
that most oxygen systems can provide supplemental oxygen for a few
minutes only (I dimly recall figures like 3-5 minutes, but that may be
inaccurate). The pilots also need to get down to 10,000 feet within
that time before everyone's oxygen generators run out.

How could an SST like the Concorde get from cruising altitude down to
10,000 feet in 3-5 minutes?


emergency descent, throttles set, dirty up, hold pitch. regularly
practiced procedure. the express elevator down.

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

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.

Passenger masks generally only need to provide sustenance for a couple of
minutes.

....the jet would have to go from let's say 30000 feet to 5000 feet in
30-45 seconds. My ears would explode.)

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.

Ten thousand is where supplemental O2 is no longer legally required. In
reality, you're back in survivable atmosphere, for most people, at about
14,000 or so. Emergency descent procedures are predicated on descending
from cruise altitude to 10,000 MSL (or an altitude where you can maintain a
cabin alt of 10K) as rapidly as is safely possible. As a practical matter,
you won't be descending at much over 12-15 thousand f/m or so, so the
descent will take a minute and a half or more.


FAR 91.211
Supplemental oxygen.
(a) General. No person may operate a civil aircraft of U.S. registry -
(1) At cabin pressure altitudes above 12,500 feet (MSL) up to and
including 14,000 feet (MSL) unless the required minimum flight crew is
provided with and uses supplemental oxygen for that part of the flight
at those altitudes that is of more than 30 minutes duration;
(2) At cabin pressure altitudes above 14,000 feet (MSL) unless the
required minimum flight crew is provided with and uses supplemental
oxygen during the entire flight time at those altitudes; and
(3) At cabin pressure altitudes above 15,000 feet (MSL) unless each
occupant of the aircraft is provided with supplemental oxygen.
(b) Pressurized cabin aircraft.
(1) No person may operate a civil aircraft of U.S. registry with a
pressurized cabin -
(i) At flight altitudes above flight level 250 unless at least a
10-minute supply of supplemental oxygen, in addition to any oxygen
required to satisfy paragraph (a) of this section, is available for
each occupant of the aircraft for use in the event that a descent is
necessitated by loss of cabin pressurization; and
(ii) At flight altitudes above flight level 350 unless one pilot at
the controls of the airplane is wearing and using an oxygen mask that
is secured and sealed and that either supplies oxygen at all times or
automatically supplies oxygen whenever the cabin pressure altitude of
the airplane exceeds 14,000 feet (MSL), except that the one pilot need
not wear and use an oxygen mask while at or below flight level 410 if
there are two pilots at the controls and each pilot has a
quick-donning type of oxygen mask that can be placed on the face with
one hand from the ready position within 5 seconds, supplying oxygen
and properly secured and sealed.
(2) Notwithstanding paragraph (b)(1)(ii) of this section, if for any
reason at any time it is necessary for one pilot to leave the controls
of the aircraft when operating at flight altitudes above flight level
350, the remaining pilot at the controls shall put on and use an
oxygen mask until the other pilot has returned to that crewmember's
station.

135.89
ilot requirements: Use of oxygen.
(a) Unpressurized aircraft. Each pilot of an unpressurized aircraft
shall use oxygen continuously when flying -
(1) At altitudes above 10,000 feet through 12,000 feet MSL for that
part of the flight at those altitudes that is of more than 30 minutes
duration; and
(2) Above 12,000 feet MSL.
(b) Pressurized aircraft.
(1) Whenever a pressurized aircraft is operated with the cabin
pressure altitude more than 10,000 feet MSL, each pilot shall comply
with paragraph (a) of this section.
(2) Whenever a pressurized aircraft is operated at altitudes above
25,000 feet through 35,000 feet MSL, unless each pilot has an approved
quick donning type oxygen mask -
(i) At least one pilot at the controls shall wear, secured and sealed,
an oxygen mask that either supplies oxygen at all times or
automatically supplies oxygen whenever the cabin pressure altitude
exceeds 12,000 feet MSL; and
(ii) During that flight, each other pilot on flight deck duty shall
have an oxygen mask, connected to an oxygen supply, located so as to
allow immediate placing of the mask on the pilot's face sealed and
secured for use.
(3) Whenever a pressurized aircraft is operated at altitudes above
35,000 feet MSL, at least one pilot at the controls shall wear,
secured and sealed, an oxygen mask required by paragraph (b)(2)(i) of
this section.
(4) If one pilot leaves a pilot duty station of an aircraft when
operating at altitudes above 25,000 feet MSL, the remaining pilot at
the controls shall put on and use an approved oxygen mask until the
other pilot returns to the pilot duty station of the aircraft.

"C J Campbell" wrote in message ...
"Ron Natalie" wrote in message
m...
|
| "C J Campbell" wrote in message
...
|
| We do not really know any such thing. If the passenger is bigger than
the
| window he simply cannot be pulled through it any more than he can sucked
up
| through a vacuum cleaner hose.
|
| Passengers are pretty flexible. Some might plug up the hole, others
will
| go through holes that looked like they ought not to fit through.
|

The windows are surprisingly large, too. I have no doubt that a small person
could get through one, especially if his seatbelt is not properly fastened.
However, you are not going to lose a whole planeload of passengers this way.
Given a choice, I would shoot a hijacker with the off chance of killing an
innocent bystander rather than allow the hijacker to drive the plane into a
crowded building.


ok.. interesting scenario. but what would be the option if the
hijacker was a midget ??