0
genoyamamoto

SIM Recommendation for two canopies out.

Recommended Posts

I might be misremembering.. and about to set myself up to be torn.. But I remeber a 4th take home from the studies.. Similar size main and reserve, and the suggestion that the reserve should be smaller then the main, as this increases the chance of a biplane forming. (something that comes to mind every time I hear people talk about having tiny mains.. do they have even smaller reserves, or do they just accept that a mismatch increases the chances of entanglement with a two out)

Good Judgment comes from experience...a lot of experience comes from bad
judgment.

Share this post


Link to post
Share on other sites
Thanks for the John LeBlanc opinion.

That's exactly what I think but I've never been in a
two out situation so for me it was all theory and thinking
about things.

I wondered about forcing a down plane in a side by side
and then cutting away but I will take John's advice.

----

Maybe we can get the Safety and Training Committee
to revisit this because I know a lot of experienced people
who think this is a better approach than releasing brakes.

Skr

Share this post


Link to post
Share on other sites
oooohhhhhh that gives me jitters just thinking about that situation of 2 canopies out.....

....i have seen many replies stating something to the effect of "as long as i was NOT heading towards an obstacle, i would not touch anything"

BUT WHAT IF YOU ARE?!
it seems likely to me that there will be tons of obstacles -- my DZ is 800 sq. ft. of field, but landing off still means houses, power lines, bardbed wire fences, trees, corn, etc.

it seems like by the time you realize your path and where you will potentially land, it would be unsafe to touch anything, BUT JUST AS UNSAFE to fly aimlessly...

** thoughts / comments / concerns?! **
~hollywood

see the world! http://gorocketdog.blogspot.com

Share this post


Link to post
Share on other sites
Quote

my DZ is 800 sq. ft



A tad bigger than that, I hope? 800 sq. ft. is 40 feet by 20 feet - my living room is bigger. Richmond web site says 40 acres of airport and 800 acres of property.

Steering with rear risers of the dominant canopy should give you the opportunity to avoid obstacles, as long as it's not at the last second. I've never had two canopies out, but I steer with rear risers of my main on every jump (for a bit). It doesn't take much of an angle change to avoid something on the ground, as long as you see it before you're on top of it.
Trapped on the surface of a sphere. XKCD

Share this post


Link to post
Share on other sites
Well, I've only had one Biplane (oops), but I didn't want to unstow the brakes on the front canopy. I was concerned that it would start flying faster than the rear canopy and be more likely to seperate into a side by side and potentially a downplane.
I just made a GENTLE rear riser turn on the front canopy to put it into the wind, no flare on landing.

Share this post


Link to post
Share on other sites
Thanks everyone for the input. I did ask this question to the USPA and I recieved the following response from them. They cite the same report that has been linked here several times.

Quote


The SIM information is based on testing done by Performance Designs and the US Army in the early 90's. This has been the only controlled testing done for main and reserve canopies deployed. In those tests, the test jumpers found that in most cases, the greatest stability was achieved steering the main canopy with toggles. It is understood that using riser control with the brakes stowed may also be appropriate in a 2-out situation. But the SIM recommendations are based on the only testing performed to date. You can read the report at http://www.performancedesigns.com/docs/dualsq.pdf
Let me know if you have any other questions.

Jim Crouch
Director of Safety and Training
United States Parachute Association
703-836-3495 ext. 314
703-836-2843 fax



Gotta go... plaything needs to spank me
Feel the hate...
Photos here

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

0