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OSP Owners,

Re: Sub 200ft Jumps

I'm either going to get an OSP or another BJ which I loved.

I'm nervous about the OSP as several threads have talked about severe end cell closure and I really can't be assed with such canopies any more. (I went through this with John Le-Blanc years and years ago).

Straight Question - Does the OSP suffer with end cell closure: Yes or No?

Thanks in advance

John

Hey John, I have never heard about end cell closure problems with the OSP - I would have thought it was the least likely canopy to suffer from this problem slider down as it has specific design features to prevent this - oversized vents as one example. I only have 10-15 jumps on mine but find it a step up in inflation characteristics and deep brake performance from my main non-vented canopies (a FOX 245 and MOJO 280). I have a couple of friends that use theirs regularly at terminal with no issues with hard openings, although that's another topic entirely...
So in answer to your question, from my experience comes a resounding no, it does not!

i only have about 15 jumps on mine, but i can say that i absolutely had end cell closure once. it was off a taller, 500 ish foot E, so i had plenty of time to deal with it but it took a few seconds to clear.........................just my own experience.

How are you loading it mate? Just out of interest...

Never had a problem with mine after 150+ jumps (285 loaded 0.7 with tuned DBS). A mate of mine (who may chip in) had bad ECC on his first jump on a 285 loaded the same as mine on factory settings - he then tuned the DBS and I don't think he has had any issues since. Both our canopies needed 5-6" out of the brakelines from the cascades.

It doesn't make sense to me that too shallow brake settings would cause ECC - maybe someone can shed some light on this???

out of curiosity did you simply shorten the fingertrap 5-6" and then jump it? or did you gradually shorten the fingertrap and jump it then shorten it, then jump, etc?

i feel like i could easily shorten my fingertrap 6" and bartack it without chance of stalling, but i was thinking about gradually shortening it and test jumpin.............any advice?

Herewith are some of the comments regarding OSP end cell closure from previous threads:

mr_prick on Jun 14, 2009, 1:58 PM
I also had end cell closures; after a talk with Stane and adjusting the brakes (a LOT deeper) it went away.

pjc on Jun 14, 2009, 12:35 PM
I have had occasional end cell closure - this hasn't affected heading but was difficult to pump out on one occasion

irish_rob on Nov 5, 2010, 4:01 AM
My first jump on the factory settings was 'interesting' (lots of end cell closure, f*ck-all canopy time!).

I haven't had end cell closure after tuning the brakes.
I'm pretty sure Irish Rob had the same experience - It does seem that the factory settings are very shallow and this seems to cause end cell inflation issues.

Transient cw
I shortened the brakes from the cascades in 2 or 3 stages. It seemed to work out on both my Troll & OSP that when you can't quite pull tension on the d-lines by pulling the packing tabs as the brakes are too short (when set in dbs) - it's about right. But that doesn't mean anything aerodynamically and would be different for different line trim, canopy sizes and wingloadings..... probably ;-)

I'll chirp in here, it was me that had severe end-cell closure on the first jump on my OSP.
We shortened the brake-lines by something like 6" in one go and it worked out to be perfect, but that's for my wing-loading and based on my factory DBS.
Co-incidentally, my DBS ended up being within 1mm of pjc's DBS after the modification.
It's probably a good idea to gradually shorten the DBS and put a test jump on each setting before shortening more.
I'm really happy with the OSP, I didn't have end cell closure after shortening the DBS and I found noticeable performance improvements over the Troll on short-delay s/d into a v tight landing area. I found the opening to be more positive and I got better feedback from the canopy while flying in v deep brakes.
I've always had good heading performance from the Troll and had similarly good heading performance from the OSP.

I know next to nothing about canopy design but do believe that end cell closure can be partly caused by lack of pressurisation as a result of the trim of the canopy i.e. the angle of attack is too shallow to fully pressurise the end cells especially during low speed deployments. This might be why the problem goes away when the DBS is substantially deepened either through the "cascade point adjustment" method or moving the DBS "cats eye" as this, I think will increase the pressure in the cells. Another potential cause of end cell closure might be under-loading the canopy which again might cause lack of immediate pressurisation. As said I really don’t know but I do feel that this is a critical issue for a canopy designed specifically for very low deployments.

I am trying to discuss this issue with Stane and have sent several e-mails to no avail. Does anyone know his current e-mail address or know if he is off jumping somewhere?

I can promise you my end-cell closure wasn't because the canopy was under-loaded...

Hi Rob,

Do you know of any one else (other than those above) who have experienced this problem?

I'm trying to determine if its wide spread and requires a design change in which case I'll postpone my purchase or if its just a handful of canopies; perhaps a QA issue.

Perhaps its not an issue at all. Just buy one and spend the first few jumps incrementally adjusting the DBS via the cascade point etc until it consistently pressurises and then when thats finally achieved start using it for what its intended for.

What do you think?

John

In the canopies that experienced the end cell closure, did the end cell closure persist long after opening?

Specifically, if the canopy was just allowed to fly (i.e. the toggles not cleared) did the end cell stay closed? Did popping the toggle fix the end cell closure?

Popping the toggles cleared the end cells and since I adjusted the DBS I haven't had an issue.
I also wasn't jumping in ideal wind conditions for first jump on new canopy (there was about 15-20kt tail wind, ideal for that particular object in general, with reflection not ideal for first jump on new kit).
The point I want to get across is the there ISN'T an issue with end cell closure on the OSP in my experience. The first jump on any new canopy is to find out what tuning is required to suit the settings to the individual. Once this was accomplished the OSP performed exactly as it was meant to. I don't believe that you should expect any new canopy to perform out of the box.
I would definitely replace my OSP with another OSP. I just wouldn't do the first jump on a new one from a 260ft A. With a 15-20kt tail wind. In the pitch dark.

John_Scher said:
"I am trying to discuss this issue with Stane and have sent several e-mails to no avail. Does anyone know his current e-mail address or know if he is off jumping somewhere?"

Update - I have received a re-assuring response from Stane:
"...If you'll decide to buy OSP we'll adjust brake setting to your weight and do test jump with the pilot of the same weight. There is zero lift at the wing tips and the most of the lift is at the central part of the canopy"

Summary
Maneno kwisha (Debate is over)