How much can landing in snow
protect you from a fall?
We've seen it save people
who jumped off a roof.
Or dived off a cliff.
And yes, even fell from the top of a mountain!
But what about a fall from even higher up?
Like, from an airplane?
Okay What-Iffers,
if you're planning on jumping out of
an airplane without a parachute,
you might want to check out our video on
what happens if you die,
because that's what you'd have
to look forward to.
The math changes depending on
how much you weigh.
But let's imagine that you weigh 65 kg (143 lbs).
As you fall from an airplane that's
thousands of meters in the air,
your body would travel at a velocity
of 55 m/sec (180 ft/sec).
And when you smash into the
solid ground below,
that velocity would instantly drop
to 0 m/sec (0 ft/sec)
causing catastrophic injuries.
But if there was a whole bunch of snow
on top of that solid ground,
it might be enough to save you from dying.
Don't believe me? Well, it's happened before ...
In 1972, a Serbian flight attendant
named Vesna Vulovic
survived the mid-air explosion of a jetliner
after plummeting
hundreds of meters through some trees
and landing on a snowy hill.
Yes, she broke her legs, pelvis,
some vertebrae and fractured her skull.
But if a little snow could save her life,
then why not yours?
But let's not get too confident here, because
there are still a ton of ways that
this could go completely wrong.
If you're going to survive,
you'll need a bunch of factors to line up perfectly.
The key to surviving a fall from an airplane
is to make your deceleration last as long as possible.
Ok, math again.
If you weigh 65 kg (143 lbs) and fall 6 km (20,000 ft),
you'd be heading down to Earth at a velocity of 55 m/sec (180 ft/sec).
If you land on solid ground,
and you only decelerate for half a second,
you'll hit with a force of 7.1 kN.
If you're not a math teacher or a scientist, that's 726 kg (1,600 lb).
But if you were able to stretch that deceleration
out by even the smallest of amounts,
it could make a world of difference.
For example,
even stretching the deceleration time out
to 1 second would reduce the force to 356 kg (786 lb).
And if you decelerate for 2 seconds, it would be 183 kg (404 lb).
Landing in a nice bed of snow could
definitely help you slow down enough to save you,
but it would have to be the right type of snow.
The snow would need to be able to compress,
slowing your fall to less than 98.2 m/sec² (322 ft/sec²)
So the snow must be thick enough for this to occur,
about 80 m (262 ft).
The reason why you need to travel at less than 98 m/sec² (322 ft/sec²)
is that this is 10 times the force of gravity,
the approximate acceleration that humans
can make without too much damage.
So considering all this,
you'd better cross your fingers that
you'll be landing in lots of soft, fresh snow.
Because of its lower density,
fresh, dry snow can be compressed more,
and soften your landing.
Packed snow, and wet snow, are denser than fresh and dry snow,
so they can't be compacted as much,
and wouldn't extend your deceleration enough to save you.
But even if you're 100% sure that the snow
you're landing in is fresh, deep and dry,
you're still not out of the danger zone.
To give yourself the best chance at survival,
you're going to want to land in a belly flop.
That may seem strange,
but it would actually be the safest choice.
If you land feet first,
all of your weight will press down on that small area.
But if you land on your belly,
your weight will be more evenly distributed,
so you won't be hurt as badly.
If, by some chance,
you happen to survive the landing
without too many injuries,
you're going to have to dig your way out of the snow.
As you can imagine,
falling all the way down from an airplane would be
pretty disorienting,
so your first step for getting out of the snow would be
to figure out which way is up.
One helpful trick that I always use
is to drool a little,
and see which direction it slides down your face.
The opposite of that is upwards.
Of course, this is all easier said than done.
In reality, there's a reason we've only heard of one person
who's ever survived falling out of a plane,
because it's very unlikely to happen,
unless you've found some way to obtain immortality,
But that's a story for another WHAT IF.