Someone mentioned that several people are killed each year from being
hit by US baseballs. For purposes of comparison, an official baseball
weights 5-5.25 ounces (a bit over 140 grams) and a thrown baseball tops
out at around 100 mph (~45 m/s), a batted ball about 20% faster.
Getting hit in the unprotected head with one can be a life-altering (or
ending) event.
A relatively modest rocket under the described circumstances (coming
straight down unbraked) could generate a similar impact. Be careful out
there.
On 11/18/2015 2:27 AM, BRITTON PAUL wrote:
It's my understanding that in the US, rockets powered by up to 'G' class
are considered 'model' rockets.
G77-4R motor has a max liftoff weight of nearly 1.5kg
Assuming a deployment fail, an airframe mass of 1kg (2.2lbs) coming in
ballistic from even 100m (~350feet) will be travelling at 44m/s (~100mph).
If it has a cast resin nosecose with nose weight in, that hitting anyone
on the head, will do fatal damage.
Paul
On 18 November 2015 at 06:57 Thom Vincent <sworkeld@xxxxxxxxx> wrote:
Thank you, all, for the responses.
I looked into this more and have a new theory. I saw several articles
mention the man was hit by a "bottle rocket". I thought they were
talking about the little pyrotechnic rockets you buy at a fireworks
store. That didn't make any sense, so I figured they had gotten the
wrong information and ignored it.
After reading these responses, though, it occurred to me they may have
been talking about a "water rocket" -- rockets made by putting water
and pressurized air in a 2 liter plastic soda pop bottle and shooting
it off.
https://www.youtube.com/watch?v=spwkO0qaoK0
If that had a hard pointy tip, no recovery mechanism deployed, and
didn't expel all its water on the way up, that could be weighty enough
to kill someone if it hit them in an eye, temple, or carotid artery.
If it was one of the more advanced types that uses multiple plastic
bottles connected together (which go higher, have more water and more
weight) that would increase the potential lethality.
http://www.aircommandrockets.com/index.htm
Beyond the obvious human tragedy, it would be both sad and ironic if
this man's death was caused by a water rocket. If so, their image as
being safe and benign may need updating.
If anyone else has info or insights, feel free to chip in ...
Thanks,
Thom
On Tue, Nov 17, 2015 at 8:28 PM, Rick Dickinson < rtd@xxxxxxxxxxxx
<mailto:rtd@xxxxxxxxxxxx>> wrote:
Just putting this in perspective - several people are killed every
year by being hit with baseballs, which are significantly
"blunter" than model rockets. Any head injury can be potentially
fatal.
On November 17, 2015 5:51:04 PM PST, Chris Jones < clj@xxxxxxxxx
<mailto:clj@xxxxxxxxx>> wrote:
On 11/17/2015 7:17 PM, Thom Vincent wrote:
Does anyone know about this? The news articles are not very
informative.
http://www.latimes.com/local/lanow/la-me-ln-man-killed-homemade-rocket-20151116-story.html
I'm trying to figure out how a model rocket can kill
somebody by
simply flying in to their face.
It only takes an unlucky hit in the wrong place to kill. If the victim
got hit in the eye, it's not out of the question for the brain to be
injured. Even a strong blow to the head from a small mass can be fatal
in some circumstances. Also, anything moving fast enough that slices a
large enough blood vessel can cause death relatively quickly.
--
Sent from my Android device with K-9 Mail. Please excuse my brevity.
