Canopy stalling just after opening, brakes stowed

[beth0b 0]

Posting this for a friend who doesn't have an account here....

I ordered a custom Spectre 170 and have put 80 jumps on it. Until recently, the openings had been nice. Recently, after my canopy opens but prior to releasing the brakes, the canopy will fully inflate, but then partially deflate where I have a “falling” sensation, then it will reinflate to “stable” flying. At this point I have not put any input to the canopy. It’s not until after releasing the brakes that it really feels comfortable to be flying under. It will sometimes even "buck" a little until brakes are released. Once brakes are released, the canopy flies, flares, and lands great.

The only thing that has been done to this canopy in it’s 80 jumps is having the brake lines shortened twice, two inches each time, and only from the cat-eye down. Maybe it’s just coincidence, but this problem on openings hadn’t happened until after the second time I had the brake lines shortened.

I’ve never had the sensation of stalling on opening like I have recently been experiencing. What could cause this?

I had two riggers independently measured the control lines from attachment point to cat-eye. They said they were correct according to the spec chart. Everything else looked to be in good shape and the line trim is measured correctly.

I am 5’7 and my exit weight is 180lbs. 300 jumps in a couple years, flew a 190 Pulse before this Spectre 170.

[skytribe 17]

I'm assuming that the lines are spectra. Yes, brake lines do shrink over time as they get heated up by the friction of the slider coming down.

I've had people tell me they need the brake lines shortened and I've questioned it - they tell me how much and its usually on the big change side. I end up saying we can do less and adjust in it small steps.

Often after a bit of toing and froing they end up with lines pretty close to where they were original. Now shortening the lines wouldn't necessarily change the cat eye position but over time the lines will shrink a little. I wouldn't think this was enough to cause stalling on opening but potentially it could. This shrinkage is going to be occurring above the cat eye so over time the brakes will be getting a little shorter.

I would tend to recheck the brake line measurements against the manufacturer's specs. As you said this only started to occur after the last shorten, try to lengthen the brake lines two inches to see if it's still occurring. If it is then you can always contact PD and send it back to them for evaluation.

PS: Everyone seems to think they have short arms which most of the time translates into not finishing the flair. This is more common for females to request shorten brake lines.

[beth0b 0]

Sorry, forgot that important piece of information... The lines are Vectran. Just verified everything is in proper trim.

[timrf79 0]

Have the risers been changed on the set-up?
Has someone else jumped the canopy and reported the same issue?

[beth0b 0]

UPT 19" risers have been used on all jumps.

One other person has jumped it but not as a "test jumper" with this issue in mind, just borrowing the gear. They did not have any problems.

[RMURRAY 1]

maybe confirm the 4" taken off below the catseye?

[beth0b 0]

RMURRAY

maybe confirm the 4" taken off below the catseye?

Yes, it was shortened below the catseye. The brake lines are the correct length from attachment point to catseye.

[ajay 1]

Does this happen on every jump? Does it clear eventually, or only when you release the toggles? I jump the same canopy with a similar, but slightly higher WL. Not all that irregularly I get a bit of funk on opening. Perfect Spectre snivel, on heading etc, but the center cells sometimes take a while to properly inflate. It causes a lot of shuddering, searching and general instability much like a stall. This clears well before I've touched the toggles, but sounds like a similar thing that you're experiencing.
Inspections reveal nothing untoward and flies fantastically otherwise, so I just put it down to my packing!

This wasn't of much use to you, I'm sure, but I'm interested to hear what people say about your experience :)

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[beth0b 0]

ajay

Does this happen on every jump? Does it clear eventually, or only when you release the toggles? I jump the same canopy with a similar, but slightly higher WL. Not all that irregularly I get a bit of funk on opening. Perfect Spectre snivel, on heading etc, but the center cells sometimes take a while to properly inflate. It causes a lot of shuddering, searching and general instability much like a stall. This clears well before I've touched the toggles, but sounds like a similar thing that you're experiencing.
Inspections reveal nothing untoward and flies fantastically otherwise, so I just put it down to my packing!

This wasn't of much use to you, I'm sure, but I'm interested to hear what people say about your experience :)

Thanks for the input.. you seem to be one of the only other people that seem to know what we're talking about.

It doesn't happen on every jump and will pretty much clear itself prior to releasing the brakes. It just seems more happy overall when it's in full flight.

Maybe it doesn't matter, but what is the DOM of your Spectre?

[ajay 1]

beth0b

***Does this happen on every jump? Does it clear eventually, or only when you release the toggles? I jump the same canopy with a similar, but slightly higher WL. Not all that irregularly I get a bit of funk on opening. Perfect Spectre snivel, on heading etc, but the center cells sometimes take a while to properly inflate. It causes a lot of shuddering, searching and general instability much like a stall. This clears well before I've touched the toggles, but sounds like a similar thing that you're experiencing.
Inspections reveal nothing untoward and flies fantastically otherwise, so I just put it down to my packing!

This wasn't of much use to you, I'm sure, but I'm interested to hear what people say about your experience :)

Thanks for the input.. you seem to be one of the only other people that seem to know what we're talking about.

It doesn't happen on every jump and will pretty much clear itself prior to releasing the brakes. It just seems more happy overall when it's in full flight.

Maybe it doesn't matter, but what is the DOM of your Spectre?

DOM 2009 ~500 jumps.

FWIW, the trashier I pack, the better it opens - God help me when I get onto something more twitchy! - Do you do anything extra in your pack jobs? Rolling the nose, excessive flaking etc..

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