
January 7th 04, 12:05 AM
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"khobar" wrote in message news:QLDKb.17987$7D3.1116@fed1read02...
running with scissors wrote in
message om...
"khobar" wrote in message
news:W_qKb.17919$7D3.14891@fed1read02...
running with scissors wrote
in
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"John Gilmer" wrote in message
...
"Bob Gardner" wrote in message
news:QODIb.85072$VB2.187788@attbi_s51...
No way. You start off at sea level, of course, and they pump the
chamber
pressure down to 25000 feet with masks on...then they do some
experiments
with a few of the pilots taking their masks off, just to show how
severely
their abilities are affected. Then comes the explosive
decompression,
which
takes the chamber from 25K back down to sea level in a second or
two.
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?
EMWTK
"they" dont. cabin pressurization is normally at 8000ft though crew
may elect to use different cabin pressures under certain circumstances
(eg medevac operations where pressurization is a factor)
Sec. 25.1 Applicability.
(a) This part prescribes airworthiness standards for the issue of type
certificates, and changes to those certificates, for transport category
airplanes.
http://www.astech-engineering.com/sy...apart25d.html#
Pressurization
Sec. 25.841 Pressurized cabins.
"(a) Pressurized cabins and compartments to be occupied must be equipped
to
provide a cabin pressure altitude of not more than 8,000 feet at the
maximum
operating altitude of the airplane under normal operating conditions."
Transport category:
* All jets with 10 or more seats or greater than 12,500lb Maximum
Takeoff Weight.
* All propeller driven airplanes with greater than 19 seats or
greater
than 19,000lb Maximum Takeoff Weight.
Obviously the rule would not normlly apply to Medivac operations.
HTH,
Paul Nixon
medevac ops are not exempt. though under certain medical conditions
the cabin my not be pressurized or pressurized to a lower altitude.
nitrogen narcosis is one condition that springs to mind.
I was thinking about medivac helicopters. Dunno why since medivac goes
beyond helicopter operations. Oh well...
Paul Nixon
pressurized heli ?
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