Are there any risks associated with performing a skydive/freefall
through clouds?  Specifically can you suffocate or drown?

Xtian666 ?

We?ll assume that you?re talking about jumping through normal cumulus
or stratus layers: you?ll be skydiving through moisture that has fog
or ice.  You?ll be a bit damper or covered with crystals ? but it
would be just like driving through fog or through a snowstorm at high
speed.

Of course, jumping through a thunderstorm?s cumulonimbus might be more
violent ? as it has both updrafts and downdrafts, which produce
significant amounts of static electricity (i.e. lightning) ? but
that?s an extreme case.

But the REAL danger is that jumpers don?t know:
?	what?s in the clouds
?	if the clouds go down to the ground, a common condition with fog
?	if the clouds go low enough that a skydiver won?t have time to open the parachute
?	what?s beneath the clouds

The U.S. Federal Air Regulations cover parachute jumping around clouds
in Part 105 section 17, ?Flight visibility and clearance from cloud
requirements.?  It is forbidden to jump through clouds ? and also NEAR
clouds.  One of the reasons is that airplanes routinely fly through
clouds on Instrument Flight Rules (IFR).

The Chuting Gallery
?FAR Part 105 ? Parachute Jumping?
http://www.chutinggallery.com/services/safety/far105.htm

The risks of jumping through clouds are very real.  In August 1967,
when I was doing my initial flight training nearby, 18 jumpers were
dropped through a cloud deck at 4,000? near Huron, OH.  Sixteen of
them drowned in Lake Erie.

They had been dropped from 20,000? near the shoreline and winds of 58
mph carried them out over the lake.  According to the New York Times
news reports from the time, jumping through clouds was illegal even in
1967.

Google search strategy:
?skydiving through clouds? risks
?FAR Part 105?

Best regards,

Omnivorous-GA

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Request for Answer Clarification by xtian666-ga on 23 Feb 2005 11:01 PST

Thanks for a great answer.  However the reason for my request was to
displel a "myth" that you can suffocate when diving through clouds:

http://www.afn.org/skydive/faq/faq.html#whuffo

"The body is able to absorb the necessary O2 through the skin. This is
why jumpers flap their cheeks in freefall, it presents a larger
surface area to the airstream for oxygen osmosis. Once under canopy,
the jumper resumes breathing normally.

This is also why jumpers do not jump on cloudy days or when they might
risk going through clouds. The moisture in the clouds can condense on
their exposed skin surfaces preventing the absorption of the necessary
oxygen resulting in suffocation. AADs are recommended for jumpers in
climates where weather is a factor."

---

Clarification of Answer by omnivorous-ga on 24 Feb 2005 03:22 PST

Xtian666 --

I'm skeptical for several reasons:
1.  I doubt the absorption of oxygen story.  Jumpers with a helmet
would have virtually no skin area exposed.
2.  suffocation would take several minutes.  A skydiver's terminal
velocity is 172 feet per second -- or 10,300 feet per minute.  Clouds
exist that are that thick -- but not clouds that jumpers would be
going through.

The Physics Factbook
"Speed of a Skydiver (Terminal Velocity)" (undated)
http://hypertextbook.com/facts/JianHuang.shtml

More worrisome to jumpers would be hypoxia, which would start in the
aircraft cabin on the ascent.  Most people start to show signs of
hypoxia above 7,000' and will have blood oxygen saturation levels drop
below 90% -- not a dangerous level but one which slows thinking. 
According to "How Stuff Works," oxygen isn't required below 16,000'
for skydivers.  Even then the jumper would be in freefall for no more
than 75 seconds:
How Stuff Works
"Skydiving"
http://stuffo.howstuffworks.com/skydiving.htm

---

In trying to assess the skin absorption issue, I used a Google search strategy of:
skin absorption of oxygen 

The National Institute of Occupational Safety & Health (NIOSH)
indicates that WHOLE body absorption of oxygen is only 10% of that
provided by the lungs:

CDC/NIOSH
"System Toxicity from Skin Exposures" (McDougal, Sept. 8-11, 2002)
http://www.cdc.gov/niosh/topics/skin/conference/s1t2.html

Obviously high speeds increase the air pressure -- but ambient oxygen
levels are lower (half at about 18,000') and little skin is exposed
during a jump.

---

This is really an aside, but a friend who trained for high-altitude
balloon flights once told me that the significant risk in jumping in
an emergency wasn't hypoxia -- they were prepared for that.  Rather,
in jumping from an airplane the skydiver has the speed to be
aerodynamic and control body position.  However, in jumping from the
balloon capsule the skydiver may start to tumble, which is both
disorienting and which makes chute deployment more risky.

I hope that this helps in settling the issue.  Often one runs into
bizarre assumptions, like the one from rec.skydiving.  I have a book
on my shelf that claims that there's less oxygen at night, a factor
that the author contends had contributed to plane crashes.  It's
nonsense but there's a small grain of truth to it: flying at night
relies on visual acuity and one of the first senses to be effected by
hypoxia is vision.  Light is much dimmer.

So, while there's NOT less oxygen at night, it IS more important for
pilots to be using it.

Best regards,

Omnivorous-GA

I have found a formal report on an FAA case regarding a violation of
FAA regulations regarding skydiving through clouds. At the end of the
report, you'll find: "Jumping through or too near clouds is dangerous,
as even Respondent?s counsel admits.  (Tr. 26-27.)  Skydivers could
collide with each other or with aircraft in the area; they could also
land in water and drown."

The flight visibility and cloud clearance safety requirements can be
found in FAR Section 105.29 (a) and (b), which state:

"No person may make a parachute jump ... --

(a) Into or through a cloud; or

(b) When ... at a distance from clouds that is less than that prescribed..."

This article contains additional information about FAA regulations
regarding skydiving through clouds:
http://www.ranchskydive.com/safety/tb_article19.htm

The United States Parachute Association posts links to detailed FAA
regulation documents at this URL: http://www.uspa.org/about/faa.htm

I have not found any formal documents beyond that outlining the
specific dangers, but I did stumble upon a few accounts of people
skydiving and hitting very low clouds that made it difficult for them
to discern their exact location in relation to landmarks and terrain
including steep hills, trees, or water.

From personal skydiving experience I can tell you that you do not
suffocate in clouds. It is just like heavy fog on land.

Hope that helps.

The page you linked to
(http://www.afn.org/skydive/faq/faq.html#whuffo) is pulling your leg.
Skydivers call non-skydivers "whuffos" because non-skydivers always
asky why (or "what for") a person would want to jump out of an
airplane.   The page you linked to makes fun of whuffos by presenting
stupid questions the whuffos ask skydivers.

So, it is not the case that a skydiver absorbs ogygen through their
skin, and it's not the case that falling through a cloud will cause a
skydiver to suffocate.

I actually went through a cloud on a sky dive.  It was a day that the
weather was not great, so for whatever reason the pilot went up to
14,000 feet instead of the normal 10,000.  When I fell through the
cloud it was colder and I felt the pricks and ticks of small ice
crystals, annoying but not painful.  It was not much different than
fog, and if felt wintery.