Tail inversion

[Kinaa 0]

I was reading a article from ABA site about nose first inflation from Dwain Weston. There is part where he mentions a tail inversion. Is it a another name for line over, or is it something other? Does it means that tail inversion is when the tail flips over the top of the canopy during canopy pressurisation?
I saw something at movie called Kollen1 from ftp.skydivingmovies.com at base section that could be tail inversion if I'm right? (the tail flips over to the top skin during the pressurisation)
Can someone who has that movie explain to me what that was (it is the part in slo/mo).
Thanks!
I.

[base311 0]

no, that's just really crappy cell pressurization aggrevated by unstowing the brakes rapidly and not immediately pulling the toggles down to stall/near-stall point during the unstow process. What you are seeing is the canopy surging when he unstows the brakes. The jumper in that instance may have had several forces working against him at that time: a tailwind (note the flag blowing on top of the object next to the exit point) which certainly didn't aid pressurization, perhaps the brakes aren't set deep enough, and he may have unstowed a bit soon before the canopy was fully pressurized. Take a look at the jumper just before him and note how much better his canopy performed.

The most likely culprits in this case are dbs, unstowing before the canopy was ready to fly and the tailwind (and possibly cut and design of canopy - I can't tell what kind of canopy that is on the vid). Sometimes when you're static lining really low stuff where you don't have much time to fly, it's better to just leave the brakes stowed and land it on risers. In the case of the guy you're asking about, he'd have been better off and gotten a better flight by landing on risers without unstowing. YMMV

Gardner

edit: sorry.. realize I didn't answer your question. Tail inversions are where the trailing edge flips under the canopy during deployment. They're considered the leading culprit for line burns on the topskin of the trailing edge of the canopy. they often clear themselves without the pilot noticing.

edit2: well, now... there seems to be some conflicting information on the web concerning what a 'tail inversion' really is. CR claims it to be what I just said, and BR claims it to be a flipping up and over the top of the trailing edge. It seems, also, that Dwain was using the term as "a flipping up and over the top" of the trailing edge, which could become a lineover.

citations:

http://www.crmojo.com/faq.htm - Consolidated Rigging FAQ see: tail inversion

http://www.basicresearch.com/tailgate.htm - Basic Research Tailgate info

http://www.basejump.org/discus/articles/nosefirst.html - The article you mentioned

[Kinaa 0]

Thanks!
When I first saw that movie I actually thought that he had broke both of his brakes.
Be safe.

Igor

[CrazyThomas 0]

last thing I heard about tail inversions, was that the Tail Gate was designed to help fight this phenomenon. Something like it restricts certain lines so that nose first inflation goes first, but the tail does not flip up.
I read (I think) on BR's website that they noticed the bottom side of the tail flipping up on some video they were studying. and then came up with the tail gate. I'm glad they did this research, and not me. I always jump a tail gate now, on low stuff, or slider off. I feel it helps my openings.
just my .02
Thomas

[TomAiello 26]

Quote

I read (I think) on BR's website that they noticed the bottom side of the tail flipping up on some video they were studying. and then came up with the tail gate.

I think that was actually their multi bridle attachment project.

As I recall, they concluded that the weight of the lines in the tail pocket was causing the tail to slump and invert during deployment. The fourth multi line (the rear one on the center cell) was intended to support the tail pocket and address this problem.

-- Tom Aiello

Tom@SnakeRiverBASE.com
SnakeRiverBASE.com