Big Canopy -- Tiny Pilot Chute

[mnischalke 0]

I got fed up with my big-ass 30-something inch F111 pilot chute on saturday as I watched it cupping air during spirals. Twice at 3k I watched it bobble around as I felt the turbulence.
So, I went to the gear shop and got a new ZP Cazer Kill Line PC with a hackey for $80. I got all psyched as we put it on during my last pack of the day. Then, I start looking at how much smaller 24-inches is than 32. Two riggers said it should pull the silhouette 210 out of the container. Well, now I'm wondering just what "should" means.
Any thoughts would be greatly appreciated.
mike
A bucket of Jet A can heat an entire county if burned all at once.

[freeflir29 0]

It's ZP...it'll work. Although I'm not positive it shouldn't be a 26 inch.......
"I got some beers....Let's Drink em!!!"
Clay

[Kris 0]

If it makes you feel any better I had a 24" ZP Cazer with a monkey fist on my old Sabre 210. Never even hesitated, always deployed cleanly. Hell, it also softened the opening like you wouldn't believe but it did have a 32" F-111 on there before...
One thing about the Cazer pilotchutes I've noticed is that they are incredibly well made. Mine put up with a lot of abuse before I sold the rig and it still looked and performed like new after 100 jumps.
Kris

[DBTECH 0]

I have over 250 jumps on a Spectre-170, with my 21" ZP PC--no problem.
Dave Brownell

[thrillseek 0]

Mike,
The difference in size is more than made up by the upgrade in fabric. Your pilot chute will actually be safer (due to the collapsable aspect of it) and more predictable, not to mention have a longer life span. From what i have heard, you bought a great brand name.
A.T.

[mnischalke 0]

Right on. Thank you all for your comments. I feel so much more confident in my gear!!
mike
A bucket of Jet A can heat an entire county if burned all at once.

[Remster 24]

Quote

Your pilot chute will actually be safer (due to the collapsable aspect of it)

Did I miss something? What does the "collapsability" of a PC have to do with its "safeness"? Maybe I misunderstood your post, but please explain....
Remster
Muff 914

[thrillseek 0]

It has been my understanding that the collapsable "kill line" PC is a safety related item...something to do with the way a pilot chute can catch and collapse the canopy if things go wrong...i persnoally have seen my pilot chute come towards the nose of my canopy, and am quite certain that if it had been the old style (w/out collapsable aspect) it would have drug itself under, instead of over my canopy...we can all imagine what happens next... So, to answer your question, not trying to be rude mate, but yes you are missing something. That is very much the reason why the collapsables are the industry standard--safety.

[PhreeZone 15]

Nope, Remi was right. Collapisible are there primarly for proformance. I've had PC's Flip over the front edge and it does'nt affect anything.
I want to touch the sky, I want to fly so high ~ Sonique

[AndyMan 7]

Quote

Your pilot chute will actually be safer (due to the collapsable aspect of it) and more predictable, not to mention have a longer life span.

There is a safety issue with it, but you got it backwards.
Collapsable pilot chutes require much greater attention while packing. Failure to 'cock' the pilot chute will result in a high speed malfuntion, which is can only be dealt with by going to the reserve. A collapsed pilot chute is one of the few exceptions to the saying "a parachute wants to open". A collapsed pilot chute certainly does not "want to open".
There are some minor safety advantages of a collapsed pilot chute. The impact of a pilot chute comming over the leading edge is much less then an inflated one. This reduces the chance of the canopy disforming. IMHO, this is a minor advantage compared to the risk of forgetting to "cock" it.

The biggest advantages of collapsible pilot chutes are performance related, not safety.
_Am

[SBS 0]

From my experience, more important than the canopy size is the container type and how tight it is. The snatch force which pulls the pin and gets the bag out of the container initially is the most important job of the pilot chute by itsself. Once the bag is in the airstream, it can open itsself...the pilot chute is there as an aide to make the deployment cleaner. Vector, for example, does not recommend small pilot chutes for any reason. I, personally, won't have one that is under 24", but prefer a 26", just because I don't see a reason to have one that small...there isn't really a benefit. Some may say that they fear hard openings, but that shouldn't be an issue until you get larger, up to 30", etc.
Just my 2 cents.
steve

[roq 0]

In my ipinion, the 21 " ZP PC is good in canopie openings but not for the PC inflate. The 21 " PC have tendency for PC in tow, because the low volume of fabric and relative wind area decrease the possibility for PC inflate. I had several hesitate PC with the 21 ".
I have any experiences with PC 21 ", 24 ", 27 " and 30 ", and I think the best option for mains until 150 sq/ft is the 24 " ZP PC.

[thrillseek 0]

Well, i never claim to be an expert... Plus i always admit if i am wrong, so if i was mistaken or rude in any way, please accept my apologies. I just jump em'...i'll let the experts decide why they design em' the way they do! :)
A.T.

[DBTECH 0]

I totally disagree with your analogy--what statistical data or physics do you have to validate your claim?
A 10" PC will inflate as fast as a 30" PC, given the same airspeed. The issue here is enough drag to pull the pin, and extract and launch the bagged canopy, which a 21" ZP-PC has more than enough of.
(45+ lbs @ 120 MPH)
PC's in tow are normally caused by improper bridle routing, and in very rare cases, an actual malfunction of the pilot chute itself. i.e., bridle half-hitched around the PC.
BTW: I knew a person back in Chicago in the late eighties that jumped a PD-107 with an 18" F-111 PC!! He never had a hesitation, let alone a PC in tow!
Whatever the size of the PC, it should always be released at full arm's length, to reduce the chance of a burble delay.
I 'now' have more than 400 jumps on my 21" ZP-PC--as said before-no problems.
Dave Brownell

[roq 0]

I have more 1000 jumps with 24" ZP PC without problems
I have + - 100 jumps with 21" ZP PC with 10 hesitations because burble delay, only in flat body opening position.
In my opinion the 21" is good in openings but bad in insuflation.

[DBTECH 0]

PC hesitation
Sounds to me possibly, compared to the 24" PC you've jumped, there may be a 'much lower porosity mesh' on the 21" PC you jumped. Additive factors may include, not full arm's length at release, and possibly larger jump suit wings.
My 21" ZP-PC uses a large hole Polyester (3/16") mesh/netting, which is very 'air transparent' compared to Nylon Marquisette mesh, that is commonly used for pilot chute construction.
I don't recall what the mesh was on the 18" F-111 PC that was jumped with the PD-107, but I do know that he never complained of any hesitations in many hundreds of jumps.
Dave Brownell

[roq 0]

Dave
I agree with you. The lower porosity mesh, and size of the hole can be reasons for hesitation PC.
My two sizes of PC compared are exactly same construction type, same hole same mesh
roq

[DBTECH 0]

Dave
I agree with you. The lower porosity mesh, and size of the hole can be reasons for hesitation PC.
My two sizes of PC compared are exactly same construction type, same hole same mesh.
rog
DB> I assume that you understood me, when I said large hole--not the hole at the base of the PC, but the hole size in the mesh itself. Mine is 3/16" or 4.7 mm.
Dave Brownell

[roq 0]

Yes. I understand. In my PC I used low porosidade mesh...
roq

[DBTECH 0]

You want 'high porosity' mesh for a PC, not low porosity mesh.
Dave Brownell

[Craig 0]

Quote

From my experience, more important than the canopy size is the container type and how tight it is. The snatch force which pulls the pin and gets the bag out of the container initially is the most important job of the pilot chute by itsself. Once the bag is in the airstream, it can open itsself...the pilot chute is there as an aide to make the deployment cleaner. Vector, for example, does not recommend small pilot chutes for any reason. I, personally, won't have one that is under 24", but prefer a 26", just because I don't see a reason to have one that small...there isn't really a benefit. Some may say that they fear hard openings, but that shouldn't be an issue until you get larger, up to 30", etc.

Just my 2 cents.

steve

I have been having some hesitations lately and own a Mirage G3(to who may not know is similar in construction to the Vector). I am using a 26 inch Cazer PC with about 65 jumps on it , used with a Triathlon 160 and as of 9 jumps ago Cobalt 135. Atair recomends this size PC for their canopy so I ended up purchasing one. In my opinion the PC is pulling the pin, but having difficulty extracting the bagged canopy. When looking back during the hesitations the PC is fully inflated and bridle is tight and at what seems full extension. As a side note a 135 is the smallest canopy Mirage suggests for the M3 so it is not overstuffed. The closing loop is not too tight as far as I am concerned since on the ground the bridle and pin is extracted without having the container leave the ground, but as you are pulling to extract the bag the container almost completely leaves the ground. I am leaving 2 to 3 inches of bridle above the pin and just barely tucking from pin to BOC. I am going to add that lazy throws couldn't be the problem cause after the first hesitation I made sure that I am not getting lazy on throwout. I am just wondering if any riggers have any comments on this. I sent an e-mail to Mirage so I am going to get their opinion on the matter but thought I would post my delimma here as well.

[Hooknswoop 19]

Kill line pilot chutes are a high wear part of your skydiving equipment requiring periodic inspection and maintenance to ensure that they will continue to function properly. Pilot chutes are deployed at 120 mph, lift the bag off your back, then it rapidly collapses as the canopy leaves the bag, and finally they are dropped onto the ground with each landing. Who hasn’t been walking back to the packing area to the calls of “dragging!”, only to discover you have been dragging your pilot chute across the ground?

Kill line pilot chutes wear at several points. The following is what to inspect and some suggestions for increasing the life span of your kill line pilot chute.

The Spectra kill line shrinks from the heat generated from sliding through the bridle as the pilot chute collapses and the bridle stretches over time, affecting the original calibration. Because the change is so gradual it often goes unnoticed until you begin to experience hesitations on deployment. To check for correct kill line length, cock the pilot chute and watch the kill line. Does it become taunt before the two white ribbons that run from the apex (the top of the pilot chute) to the bridle? If it does, then the kill line is too short, not allowing the pilot chute to completely inflate. When cocked, the two white ribbons should be taunt and there should be some slack on the kill line. Also, if the handle of the pilot chute being pulled through the small opening at the base of the pilot chute on deployment, the kill line is too short. Your rigger should be able to replace the kill line, or if the kill line was manufactured with enough excess line, your rigger can simply extend the kill line.

Check the stitching that holds your handle to the pilot chute. If the handle rips off, you would have a total malfunction. Check the bridle, especially where the pin attaches to the bridle. If any of the stitches have come out, have your rigger repair it. If the pin rips off of the bridle you would have a pilot chute in tow malfunction. As you fly your canopy, the deployment bag is free to spin around the bridle. Eventually the bridle will wear out and break at the grommet. Have your rigger use waxed nylon cord to tack both sides of the rapide link to the reinforced part of the deployment bag to prevent the bridle from rotating in the grommet. Some manufactures sew the pilot chute bridle to the deployment bag, eliminating this problem. The disadvantage of a sewn-in pilot chute is they are difficult to replace, usually a job for a rigger. Lastly, have your rigger install stainless steel rapide links instead of the plated links. They won’t corrode, reducing wear on the bridle.

Whether your pilot chute is a kill line or not, the Z-P or F-111 fabric wears just like the fabric on a canopy. The porosity of the fabric degrades with use, decreasing the drag of the pilot chute. Eventually the pilot chute will not have enough drag to deploy your main canopy, leaving you with a pilot chute in tow or a bag lock. An indication that your chute may have problems is a pause between throwing your pilot chute and the canopy coming out of the bag.

A patch on a pilot chute would be difficult to sew and could cause it to spin on deployment, creating lines twists. As the mesh wears, holes will develop. Once the mesh tears the hole will become larger quickly. Replace a pilot chute with holes in the fabric or mesh.

Checking your pilot chute every time you do your 30-day three-ring maintenance is simple and could prevent a malfunction. If you are not confident inspecting your pilot chute, have your rigger help you. An ounce of prevention is worth a pound of cure.

Hook

[Craig 0]

Good info here. In my case the PC is almost new, you cannot blow through the ZP fabric and meets the criteria for proper construction according to the post by Bill Booth several months back. Also I don't think I mentioned in my post that when watching the bag lift off the lines un-stow smoothly with no hesitation.

[Hooknswoop 19]

http://www.relativeworkshop.com/main.html

This is for the VectorIII/Micron, but should apply to the Mirage also.

I have seen very new PC's out of calibration.

Hook

[bobsoutar 0]

If that is the case then the PC is doing it's job. You can speed the process up a bit by leaving extra un-stowed line in the container (should be at least 18" anyway).
Sounds like your hesitation is at the canopy inflation stage. Cobalts have a 2 stage opening which takes some getting used to, I understand. Check their website for more info.