Opening Distances

[MyUserID 0]

Some of you might remember that I'm doing a project on harness comfort. Anyway, I've been working on that, and lastnight, I was reading that opening snatch force can be as much as 10 Gs and that canopes open in about 120 feet. I dunno, that doesnt seem right to me. I thought the Gs were less and that most canopies opened in longer distances than that. Basically, does anybody know the average opening distances of some of the more common canopies out there?

[gemini 0]

A Triathalon opening is 400-1100 feet depending on how the nose and slider are packed. 10G sounds like it would hurt a lot!
Gemini
... Fear? Fear is riding the plane down ...

[jumpervali 2]

Reserves are tested to open in 300 ft. @ 200 mph. 10 times before there put into production.
jumpervali

[Geoff 0]

Quote

I was reading that opening snatch force can be as much as 10 Gs and that canopes open in about 120 feet

Where were you reading this?
Geoff

[MyUserID 0]

I believe it was in the "Parachute Manual" by Dan Poynter on page 310. Not sure which volume though.

[jumpervali 2]

"snatch force"
The things you'll do to get some p*$$y
jumpervali

[DBTECH 0]

Normal opening forces (not snatch force) occur over a period of approximately two to four seconds, over a distance of two hundred feet or more. Mean/normal deceleration numbers are 2 to 4 g's.
Check out my article on opening physics at-->
http://dzsports.net/dznewsbin/news20018.html
Dave Brownell
Mesa, AZ

[Jimbo 0]

Quote

and that canopes open in about 120 feet.

Yikes! Maybe old Sabre's. A canopy opening in 120 feet could literally break your back. That would be bad.
Most 'modern' canopies open in 600 to 800 feet. Some are a bit quicker, some a bit slower. My Safire usually takes somewhere between 800 and 1100 feet. Nice and soft, just the way I like it.

[freeflir29 0]

My PD-190 opens quick but smooth in about 500 Ft. almost every time.
"and I'm not easily impressed...Ooohh look...a blue car!" -Homer Simpson

[DBTECH 0]

>and that canopies open in about 120 feet.
--------------------------------------------------------------------------------
Jimbo responded-->
Yikes! Maybe old Sabre's. A canopy opening in 120 feet could literally break your back. That would be bad.
DB> Not really 'that bad'---'data' from my article--->
A deceleration from 120 MPH to 10 MPH over a distance of 30 feet would be 16 g's nominal-which is well into the range of a gut wrenching opening--Yikes, for sure! Yes-been there-done that-no fun. (both steering lines broke, and the opening actually deformed two #4 Stainless/delta connector links!--(I did land it via the rear risers) (PD-210-line dump-ten+ years ago)
The canopy was packed by a master rigger who claimed to have all the answers--but I now know, like many--he's yet to see the questions.
Dave Brownell
Mesa, AZ

[GrumpySmurf 0]

"The canopy was packed by a master rigger who claimed to have all the answers"
And let me guess - they were all '42'?

[Jabeln79 0]

I have a Triathalon 190 and it almost always takes around 1200' to open... Alhtough i like it like that it makes for a super soft opening..

[skymedic 0]

Dave, I cared for a guy that broke his neck from a saber smack....he said it opened in around 100-130 ft...how he determined this distance not sure...but definatley did break his C-2 through C-5....the man is still walking.....thanks of course to great medical care....
Marc
Res Firma Mitescere Nescite

[DBTECH 0]

A deceleration from 120 MPH to 10 MPH over a distance of 30 feet would be 16 g's nominal-which is well into the range of a gut wrenching opening.
The above is derived from good math--not fuzzy math.
The above model is for a constant 16 G's over a distance of 30 feet.
Yes-been there-done that-no fun. (both steering lines broke, and the opening actually deformed two #4 Stainless/delta connector links!--(I did land it via the rear risers) (PD-210-line dump-ten+ years ago)
The above opening was probably into the realm of less than 75 feet/16 G's peak--based on the damage to the connector links, riser dive loop stitching, and broken lines-(especially the connector link deformation, which I have a good feeling for--for the numbers. Even with 'only' 700 lbs. peak on each riser/connector link-that would be 16 G's peak! 4 X 700=2800 over 175= 16 G's-ouch! Ya dig!
Dave Brownell
Mesa, AZ

[freeflir29 0]

Dave! Did ya shit yourself? Chuck has proven that it's not really a hard opening unless you shit yourself........"and I'm not easily impressed...Ooohh look...a blue car!" -Homer Simpson

[landmissle 2]

Freeflir29,
That's too funny!!!! Hard-openings aren't an absolute requirment to shit oneself since I nearly did after reading your post. Ya' had me snickering so bad I had to close my office door so my peers wouldn't think I was some cackling lunatic.
Thanks for the Monday morning blue's breaker!
Feet up, heads down, blue skies,
Landmissle

[freeflir29 0]

I had one once where I was in pain for the whole canopy ride. An aeroglide 235 of all things. Never would I have thought such a big canopy could open so hard........but I didn't shit myself......so I guess it wasn't that bad......
"and I'm not easily impressed...Ooohh look...a blue car!" -Homer Simpson

[Stacy 0]

my first canopy was a falcon which woudl open in 500 feet fairly consistently. Second canopy was a spectre which varied from 700-1000 foot openings, depending on the packer. My jedei is consistent at about 1000-1200 foot openings, so slow I can actually watch it open up each time.
Stacy
http://astro.temple.edu/~sweeks