On Jan 19, 12:53 pm, Morris Dovey wrote:
On 1/19/2010 12:59 PM, tom wrote:

Unfortunately, we'll probably never know how many successful jumps
were made from "Big Brutus". I'd recommend static-lining off that low
of a height. Tom

I would not. The training towers at Ft Benning are 250' tall and "jumps"
are made with an already-open canopy (note the shadow in this photo):

http://www.army.mil/-images/2008/07/....mil-2008-07-2...

(In ancient days back when I was indestructible I rode to the top of the
tower in the background of that photo. The trip up is scarier than the
trip down, and I quite understand this young woman's slight nervousness.
)

I recall being told that the T-10 parachute needed ~200' to deploy and
fully inflate in a static line jump from an aircraft going ~125 mph -
and that the minimum (very high risk) static line combat jump altitude
was 300'.

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USAhttp://www.iedu.com/DeSoto/

That jumper doesn't have his feet together...Fort Benning is a haven
for broken ankles. The equipment has changed drastically since we went
from round to square parachutes, silk or pongee to zero-porosity rip-
stop fabrics. I think when the figures you recall were accepted, they
took into account the oscillation factor, the swinging that occurrs
when your round canopy opened in a horizontal configuration. Jumping
from a moving platform, you must also add that "forward throw"
distance into the mix. At 125 mph, you'll probably travel 300 feet
horizontally before you've gone a hundred feet vertically.