Catastrophic Decompression; Small Place Solo

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,

George
************************************************** ********************
Dr. George O. Bizzigotti Telephone: (703) 610-2115
Mitretek Systems, Inc. Fax: (703) 610-1558
3150 Fairview Park Drive South E-Mail:
Falls Church, Virginia, 22042-4519
************************************************** ********************

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?

Easily. My MU-2 can descend 10,000fpm. Any jet can easily do it.

Mike
MU-2


"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?

"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?

I'd guess about 3-4 minutes from FL600 to 10K. Just my guess, never read up
on the craft. But 12-15 K ft/m would not be unusual in an emergency
descent.


Regards,

John Gaquin
B727, B747

"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?

Push the yoke forward :-)

On Wed, 31 Dec 2003 at 11:53:49 in message
, Scott M. Kozel wrote:

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

I believe with the two inboard engines on reverse thrust the outer two
on idle. On my only Concorde flight (a test with volunteer passengers)
we descended from cruise height with two engines on reverse thrust. All
I remember was that the clouds below seemed to come up very fast!
--
David CL Francis

"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

Mish

Do you have enough bleed air with throttles at idle?

Thrust curve is not linear with throttle position so some rpm above
idle might be required in some birds???

Change in time down to 18K or so would not be much different. I used a
figure of 18K as a target alt to get on the safe side in a emergency
descent.

USAF set 34K (cockpit altitude) as the point to go to pressure
breathing. Easy to suck in and fill lungs and hard to breath out (open
exhaust valve). This assisted the lungs to get enough oxy. Took a
while to accustom to blowing out with each breath against valve but
soon became routine.

Big John
Pilot ROCAF


On Mon, 05 Jan 2004 18:38:52 GMT, "Gary Mishler"
wrote:


"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

"Big John" wrote in message
...

Do you have enough bleed air with throttles at idle?

Thrust curve is not linear with throttle position so some rpm above
idle might be required in some birds???

The Lear 60 has big Pratts on it so it does have enough bleed air to run
everything at idle. The 50 and 30 series Lears I flew didn't usually have
enough bleed air at idle to run both pressurization and anti-ice. Like you
said above, on those planes you had to have some power greater than idle to
hold the cabin with anti-ice on.

Now on the old 20 series lears I hear you had to have the rpm up just to
hold cabin altitude.

Hope that answers your question,
Mish

"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.