Airbag/Ballute Instead of Parachute
mano...@gmail.com
minimize the vulnerable parachuting phase where the parachutists are
vulnerably exposed while floating down, then what about an airbag
solution?
When you look at videos of automobile airbags inflating, they do so at
lightning speed, before your head can even hit the steering wheel or
windshield.
http://www.edinformatics.com/inventions_inventors/airbag.htm
What if you had a airbag that explosively inflated at the last moment,
to generate the drag+buoyancy to rapidly slow down your freefalling
skydiver nearer to the end of their descent? I'm picturing an airbag
that would explosively inflate with hydrogen gas for buoyancy and not
just drag. The "H-bag" would inflate below the skydiver, and not above
them, so that it could also act as a shock-absorber between the
skydiver and the ground, similar to the automobile airbag. It would
have to instantaneously inflate to a large enough size to 1)cause rapid
deceleration from buoyancy+drag and 2)create a large and safely
decelerative shock absorber between the skydiver and the ground.
I'm imagining the airbag would be stored in a device that would be
strapped on to the bottom of your feet, sort of like a snowboard. Or
else it might look like a pogo stick, and you would ride it that way.
I'm presuming that feet-first is the best way for the body to handle an
impact. I'm also presuming that the highest deceleration rate the body
can safely handle along its vertical axis is at 8 G's.
The H-bag would explosively inflate below the skydiver in the shape of
an elongated teardrop -- actually more like a clove of garlic with 4
bulging lobes. I'm imagining the extent to which each lobe is inflated
would be calibrated based on the trajectory/disposition of the
skydiver. Likewise, the altitude at which it triggers is based on the
speed of descent. As the H-bag contacts the ground, the skydiver would
plunge through the middle of it to contact the ground at reasonable
speed.
If you had to jump out of a tall building, Sept11-style, the H-bag
could work there too.
For the sake of discussion -- in a typical skydive, how large a size
would the H-bag have to inflate to, and what would be the best height
for it to trigger at, in order for you to safely reach the ground?
Any ideas?
mike Williamson
Several ideas, none of which are conducive to your idea working:
1- A person not well trained and practiced in free-fall parachuting
would only be correctly oriented prior to impact due to sheer chance.
If you are below the airbag when it deploys, you'll be cushioning
IT'S impact rather than the other way around.
2- The best way to take a deceleration in not in the vertical axis,
but fore/aft (with proper distribution of forces). While the
backbone can take 8 G's or even more, this won't happen if you
aren't in a good position, and in freefall, you're virtually
guaranteed that you won't be in a good position to take the
acceleration. You'd also tend to break your legs and/or
seriously screw up your knees and ankles landing on an airbag that way
if your don't just plain kill yourself.
3- How do you ensure correct deployment altitude of the airbag? You
want to deploy the device immediately before impact, which gives you
no margin for error- if it fails to inflate, you aren't going to have
the time to deploy a reserve, or anything similar.
4- given the necessary size of the airbag, the device is going to
be significantly bulkier than a parachute, resulting in fewer troops
able to be carried by a given transport, and quite possibly resulting
in slower exit from the aircraft (not as many troops exiting in a
given time).
5- The troops will be carrying a very high horizontal velocity at the
time of airbag deployment, and subsequently on impact. This means that
they are going to hit the ground (which may well be uneven and/or
strewn with debris. You have a good chance of the bag not staying
stable, resulting in the bag/body tumbling and/or rolling
before coming to a stop. Additionally, if you tear out the bottom
of the bag, it won't provide protection for the rest of the ride
in any case.
All in all, you have a heavier, bulkier, more complex system that
is less likely to work safely than the existing system which is
already in place. If you want simply to reduce the time spent
vulnerable to fire, you could simply delay opening a conventional
parachute, which would leave you with problem 3 above but not
introduce any new ones, although low altitude drops using static
lines are already intended to minimize both the vulnerable time
spent under a chute and drift away from the DZ due to winds, etc.
Mike
John Gentry
"mano...@yahoo.com" <mano...@gmail.com> wrote in message
news:1128213960.4...@g44g2000cwa.googlegroups.com...
tom
mano...@gmail.com
more in the shape of a mushroom/toadstool? The top of the toadstool
would catch more passing air, so that the increased aerial drag would
reduce horizontal and vertical speed. Meanwhile the lower part of the
toadstool would be tougher, and able to take the main shock of
touchdown.
The skydiver would then fall in a spread-eagle position, and would be
resting on the top of the toadstool when it hit the ground. He might
need some kind of neckbrace however. The lower part of the toadstool
would be filled with bubbles/pockets which would burst upon touchdown,
using cell-collapse effect to help dissipate energy of impact, rather
than causing the whole thing to bounce and roll over.
You would have comparable drag to a parachute, but
1) you would also benefit from H2 buoyancy
2) you would be able to hit the ground at higher velocity due to airbag
protection
3)because it inflates, there's less chance of fouling as with parachute
lines, and you don't have to worry as much about incorrect packing
4)you would wear it like a pancho/windbreaker
It could use electronics, such as laser rangefinder to track descent
trajectory and trigger appropriately. The electronics would have their
own built-in redundancy.
How about that?
Keith W
> Alright, suppose we increase aerial drag by making our H-bag ballute
> more in the shape of a mushroom/toadstool? The top of the toadstool
> would catch more passing air, so that the increased aerial drag would
> reduce horizontal and vertical speed. Meanwhile the lower part of the
> toadstool would be tougher, and able to take the main shock of
> touchdown.
>
> The skydiver would then fall in a spread-eagle position, and would be
> resting on the top of the toadstool when it hit the ground. He might
> need some kind of neckbrace however. The lower part of the toadstool
> would be filled with bubbles/pockets which would burst upon touchdown,
> using cell-collapse effect to help dissipate energy of impact, rather
> than causing the whole thing to bounce and roll over.
>
It wouldnt help much
Assuming your airbag is 2ft thick and impact velocity is circa 120mph
and final velocity is 0 then acceleration is given by v*v= 2as
thus final acceleration (a) = (v*v)/2 *2
where v=velocity (176 ft/s)
a= (176*176)/4=7744 ft/sec2= 242 gravities
Human beings dont stand up to such accelerations at all well.
The NHTSA standard for a sudden impact acceleration
on a human that would cause severe injury or death is
75 g's for a "50th percentile male", 65 g's for a
"50th percentile female", and 50 g's for a "50th percentile child"
Keith
tscottme
> If military para-drops have to occur at low altitude in order to
> minimize the vulnerable parachuting phase where the parachutists are
> vulnerably exposed while floating down, then what about an airbag
> solution?
>
My skydiving experience is limited to static-line jumps from small civilian
aircraft. However my friend in college was a member of US 82nd Airborne and
had numeorus jumps. He indicated, and I've since confirmed this with
reports in Aviation Week magazine, that if commanders are worried about
dropping troops and having them shot at while under canopy, they simply drop
the troops very low. The paratrooper indicated they had numerous drops that
were so low they barely had time to swing under the canopy before they hit
the dirt. He explained it as opening shock, swing, swing, thud. AW&ST
reporting indicated the lowest successful opening of a combat-equipped
soldier was 300 feet above ground. You can make up for very low altitude
drop by increasing the airspeed at which you deploy the troops.
I don't recall a lot of paratroop drops while under fire. Sure they are
capable of dropping into a hot drop zone and fighting immediately.
Typically they are dropped in conditions less hostile than seen in the war
movies.
--
Scott
By pretending that all cultures are equal, multiculturalism doesn't
'preserve' traditional cultures so much as sustain them in an artificial
state that ensures they'll develop bizarre pathologies and mutate into some
freakish hybrid of the worst of both worlds.
Mark Steyn
mano...@gmail.com
ground, just much lower than when you'd deploy a parachute.
Suppose the H-bag deployed at 30 to 50 feet above the ground, instead
of 2 feet away from the ground? Electronics would judge the best
distance for deployment, based on trajectory/velocity/disposition.
Lying on a gasbag could be less stressful on the body than being jerked
by a parachute harness.
Perhaps the venting gas from the H-bag could also make use of
ground-effect for further braking ability.
ascii art of toadstool cross-sectional shape:
_______ _______
/ _____ \o-\-</ _____ \
|/ \ / \|
\_____ /
Also consider that parachutes are more visible and thus are a big
giveaway that a para-drop is occurring. If you have something that
deploys at lower altitude, it is less visible above the horizon.
Also note that the H-bag is not intended to be reusable, like a
parachute is.
It's supposed to tossed away disposably.
mano...@gmail.com
_______ _______
/ _____ \o-\-</ _____ \
|/ \ / \|
\_____ /
The o-/-< is of course the little man
But maybe this idea could be used for Martian lander probes too.
Peter Twydell
"mano...@yahoo.com" <mano...@gmail.com> writes
>If military para-drops have to occur at low altitude in order to
>minimize the vulnerable parachuting phase where the parachutists are
>vulnerably exposed while floating down, then what about an airbag
>solution?
>
>When you look at videos of automobile airbags inflating, they do so at
>lightning speed, before your head can even hit the steering wheel or
>windshield.
>
>http://www.edinformatics.com/inventions_inventors/airbag.htm
>
>What if you had a airbag that explosively inflated at the last moment,
>to generate the drag+buoyancy to rapidly slow down your freefalling
>skydiver nearer to the end of their descent? I'm picturing an airbag
<snip painful-sounding proposition>
>
>Any ideas?
>
1. Why not fit the jumper with wings and a tailplane? Maybe little
wheels, too.
2. Use the blind jumper's technique: jump with a dog and pull the
ripcord when the lead goes slack.
--
Peter
Ying tong iddle-i po!
Keith W
> well, like I said, it's not supposed to deploy exactly when you hit the
> ground, just much lower than when you'd deploy a parachute.
> Suppose the H-bag deployed at 30 to 50 feet above the ground, instead
> of 2 feet away from the ground?
Assuming a 2 ft thick pad and a max acceleration of 8 gees
the max terminal velocity at impact must be no more than
30 ft/sec
Now terminal velocity is around 224 ft/sec so that means you need
enough braking to lose 194 ft /sec in 50 ft
v*v=u*u + 2as
224*224=30*30 + 2*a*50
so we get
a= (50176-900)/100
a= 54 ft/sec2
That requires a huge braking force calculated by the formula
F=Ma
The caclulation of which I leave as an exercise for the reader
suffice it to say thats it more than is reasonably achievable
in your design.
Keith
george
tscottme wrote:
> "mano...@yahoo.com" <mano...@gmail.com> wrote in message
> news:1128213960.4...@g44g2000cwa.googlegroups.com...
> > If military para-drops have to occur at low altitude in order to
> > minimize the vulnerable parachuting phase where the parachutists are
> > vulnerably exposed while floating down, then what about an airbag
> > solution?
> >
>
> My skydiving experience is limited to static-line jumps from small civilian
> aircraft. However my friend in college was a member of US 82nd Airborne and
> had numeorus jumps. He indicated, and I've since confirmed this with
> reports in Aviation Week magazine, that if commanders are worried about
> dropping troops and having them shot at while under canopy, they simply drop
> the troops very low. The paratrooper indicated they had numerous drops that
> were so low they barely had time to swing under the canopy before they hit
> the dirt. He explained it as opening shock, swing, swing, thud. AW&ST
> reporting indicated the lowest successful opening of a combat-equipped
> soldier was 300 feet above ground. You can make up for very low altitude
> drop by increasing the airspeed at which you deploy the troops.
>
> I don't recall a lot of paratroop drops while under fire. Sure they are
> capable of dropping into a hot drop zone and fighting immediately.
> Typically they are dropped in conditions less hostile than seen in the war
> movies.
>
BASE
mano...@gmail.com
substantially lower than what you can get with a parachute -- and an
airbag that's 4 feet thick?
You could allow for a short-term peak deceleration rate of 12 G's,
since you're spread-eagled on an airbag. It could still be more
comfortable than a parachute.
What's the peak G-forces felt by a parachutist, anyway?
Keith W
> Alright, what about a distance of 100 feet -- which is still
> substantially lower than what you can get with a parachute -- and an
> airbag that's 4 feet thick?
>
Do the math, I have given you the equations
Keith
Mike Spurgeon
> Alright, what about a distance of 100 feet -- which is still
> substantially lower than what you can get with a parachute -- and an
> airbag that's 4 feet thick?
Move the goal posts all you want.
It's not going to work.
Successfully...
WaltBJ
less than 100 feet above the ground. He was hanging onto a strut and
pulled the ripcord - the chute inflated and off course yanked him right
off the wing. Guess a Stearman could drop troops two per plane. Or we
could refit a C130 with rows of MartinBaker seats and the jump could be
done from just above the ground. Might take some pretty good timing to
keep the empty seats from hitting the next troop in line. all the jump
master would need is a great big D-ring.
Walt BJ
Walt BJ
Dave Kearton
You only need to see the airbags that stuntmen jump into for movies.
Saw one on TV, the other day for a jump of 10 floors (approx 4m per floor) -
let's say a 50m jump, the airbag was 2 to 2.5m thick and the size of half
a tennis court. It had to be kept inflated by a large compressor to
compensate for the air leaking from the outflow vanes.
Most of the basic problems could be overcome ........
A drogue chute will keep the paratrooper oriented the right way for impact
on his airbag.
Forget about hydrogen, no loadmaster on the planet would allow 50
paratroops with Hydrogen tanks aboard a Herc going into a hot zone (play
"One way ticket to Paradise" at loading) Stick to the same pyro
that the airbags use, it's smaller, lighter and doesn't leak inside the
cabin - causing the crew to speak in high, funny voices.
I don't think a 4' pad is ever going to be safe, by the time you're done,
your mattress is likely to be 4m thick. A simple radar altimeter
could deploy the bags in time for impact. Just hope that the bad
guys haven't got a portable ECM kit that can confuse or block their signals.
_IF_ you could get it to work - and that's your big problem, the numbers
don't look promising - the first combat deployment would be quite
impressive. Hercs fly overhead at 15,000' dropping out hundreds of
troops, none of whom have parachutes that open. The enemy on the
ground, watching the drop, would hear the "Brrrrppp" burst of the bags
deploying, like gunfire, followed by hundreds of incredibly loud farts as
the airbags forcibly deflate.
The sight of the paratroops running for cover and re-forming into teams
after the drop would add to the "shock & awe" TM.
In the end, given the ability to suppress an area with air support in all
weather, something that wasn't available at Arnhem, is it really worth the
trouble and expense for an insertion vehicle that may never again be used in
combat ?
--
Cheers
Dave Kearton
Mike Spurgeon
And in WWII, some troops were dropped low and slow in bags of
straw with enough surviving to justify it in some minds, but
we're beyond 'enough' now...
Mike Spurgeon
> Mike Spurgeon wrote:
>>> It's not going to work.
>>>
>>> Successfully...
> Most of the basic problems could be overcome ........
From what you're writing, you haven't even identified the
'basic' problem.
Others have, and you guys continue to ignore them...
Dave Holford
Mike Spurgeon wrote:
Imagine the fun of a premature deployment in the aircraft!
Dave
Dave Kearton
That's right - not enough straw.
Genius
--
Cheers
Dave Kearton
Andrew Taylor
news:ZoCdncqyD8P...@comcast.com...
>
> My skydiving experience is limited to static-line jumps from small
civilian
> aircraft. However my friend in college was a member of US 82nd Airborne
and
> had numeorus jumps. He indicated, and I've since confirmed this with
> reports in Aviation Week magazine, that if commanders are worried about
> dropping troops and having them shot at while under canopy, they simply
drop
> the troops very low. The paratrooper indicated they had numerous drops
that
> were so low they barely had time to swing under the canopy before they hit
> the dirt. He explained it as opening shock, swing, swing, thud. AW&ST
> reporting indicated the lowest successful opening of a combat-equipped
> soldier was 300 feet above ground. You can make up for very low altitude
> drop by increasing the airspeed at which you deploy the troops.
>
the open rear tailgate of a C140. Kit is dropped separately apart from
personal arms and ammo.
Andrew Taylor
> If military para-drops have to occur at low altitude in order to
> minimize the vulnerable parachuting phase where the parachutists are
> vulnerably exposed while floating down, then what about an airbag
> solution?
>
a certain amount of deafness. When the basket ball equipped person bounces,
the enemy might be able to get a few extra shots in, after all they practice
on pop-up targets :>) It is not unknown for parachutists to hit other things
apart from the ground, rocks, trees, buildings etc. At least with a
parachute, you can dangle.
Keith W
"Dave Kearton" <dkearton.·´¯`·.¸¸.·´¯`·.¸<º))))@ozemail.com.au> wrote in
message news:_WZ%e.18$yz4...@nnrp1.ozemail.com.au...
>
>
>
> You only need to see the airbags that stuntmen jump into for movies.
> Saw one on TV, the other day for a jump of 10 floors (approx 4m per
> floor) -
> let's say a 50m jump, the airbag was 2 to 2.5m thick and the size of
> half
> a tennis court. It had to be kept inflated by a large compressor
> to
> compensate for the air leaking from the outflow vanes.
>
And the stuntman isnt going to be at anything like
the terminal velocity of a skydiver. At best from 150 ft
he'll be doing around 100 ft/sec. A paratrooper will be
doing around double that and carrying weapons and ammo.
Keith
Doz
much!
I pref the Martin Baker idea better... at least nobody would be late leaving
and the aitcraft would be a lot lighter on the way home!
"Andrew Taylor" <andrewcr...@spamcopSUBVERSIVE.com> wrote in message
news:4340c...@newsgate.x-privat.org...
Tom B
"Doz" <D...@Doz.Doz> wrote in message
news:4340f907$0$25089$db0f...@news.zen.co.uk...
> well... that was one interesting read.. my face still hurts from laughing
> so
> much!
>
> I pref the Martin Baker idea better... at least nobody would be late
> leaving
> and the aitcraft would be a lot lighter on the way home!
Having seen three surviving pilots up close after riding ejection seats, I
think I would almost prefer the airbag. At least it would not hurt the rest
of my life. :)
Tom B
Peter Stickney
IIRC, when they were doing tests of the seats & capsule for the B-58,
the Air Force set up a B-47 to launch the seats/capsule out of the
bomb bay. I can't think of any reason that teh same thing wouldn't
work with a B-52 - Consider the pinpoint accuracy of a HALO drop
triggered by the K-System.
--
Pete Stickney
Java Man knew nothing about coffee.
Peter Twydell
<d16...@aol.com> writes
(Hornet/Meteor/Hunter/Canberra/Harrier) who banged out of a Hunter in
the 1960s. He was still having infrared treatment 20 years later.
davidov...@gmail.com
> If military para-drops have to occur at low altitude in order to
> minimize the vulnerable parachuting phase where the parachutists are
> vulnerably exposed while floating down, then what about an airbag
> solution?
>
> lightning speed, before your head can even hit the steering wheel or
> windshield.
>
> http://www.edinformatics.com/inventions_inventors/airbag.htm
>
> What if you had a airbag that explosively inflated at the last moment,
> to generate the drag+buoyancy to rapidly slow down your freefalling
> skydiver nearer to the end of their descent? I'm picturing an airbag
> just drag. The "H-bag" would inflate below the skydiver, and not above
> them, so that it could also act as a shock-absorber between the
> skydiver and the ground, similar to the automobile airbag. It would
> have to instantaneously inflate to a large enough size to 1)cause rapid
> deceleration from buoyancy+drag and 2)create a large and safely
> decelerative shock absorber between the skydiver and the ground.
>
> I'm imagining the airbag would be stored in a device that would be
> strapped on to the bottom of your feet, sort of like a snowboard. Or
> else it might look like a pogo stick, and you would ride it that way.
> I'm presuming that feet-first is the best way for the body to handle an
> impact. I'm also presuming that the highest deceleration rate the body
> can safely handle along its vertical axis is at 8 G's.
>
> The H-bag would explosively inflate below the skydiver in the shape of
> an elongated teardrop -- actually more like a clove of garlic with 4
> bulging lobes. I'm imagining the extent to which each lobe is inflated
> would be calibrated based on the trajectory/disposition of the
> skydiver. Likewise, the altitude at which it triggers is based on the
> speed of descent. As the H-bag contacts the ground, the skydiver would
> plunge through the middle of it to contact the ground at reasonable
> speed.
>
> If you had to jump out of a tall building, Sept11-style, the H-bag
> could work there too.
>
> For the sake of discussion -- in a typical skydive, how large a size
> would the H-bag have to inflate to, and what would be the best height
> for it to trigger at, in order for you to safely reach the ground?
>
> Any ideas?
Hi, this is a really old thread Ive come across - but interesting - anyone still following it?