PEPs with square canopies

[riggerrob 558]

Dear Hackish,

When you are that low ... and have made that many mistakes .... squares deploy more consistently than rounds.

Please remember that large, docile squares suffer fewer malfunctions than rounds.
I saw a dramatic reduction in main mals as we (1980s) transitioned from rounds to squares.
The only rounds that I would trust (to deliberately deploy) below 500 are military static-line canopies with direct-bags, anti-inversion nets, etc.

The only round PEP canopies that come close (in reliability to squares) are Butler's HX series of PEP canopies with sliders, but they cost as much as square canopies.

The belief (that rounds deploy more reliably than squares) was true back in 1980, but squares have gotten more reliable since then ... more reliable than rounds.
Just another case of "generational stagnation" with pilots quoting whichever fragment of ancient lord that supports their purchasing decision.

[JerryBaumchen 1,047]

Hi Rob,

Quote

The only rounds that I would trust (to deliberately deploy) below 500 are military static-line canopies with direct-bags, anti-inversion nets, etc.

We each get to trust what we want to trust.

If the Fall of 1964 I watched a guy unpack a gut pack with no pilot chute at 300 ft. Not a long canopy ride but he landed without any injury. And it was my 24 ft twill reserve that he used.

In the Spring of 1965 I watched a guy unpack a gut pack with a pilot chute at 400 ft. Again, not a long canopy ride but he also landed without any injury.

You roll the dice and you get what you get.

Jerry Baumchen

[hackish 8]

Rob,

Among skydivers I believe you. A stable deployment by an experienced jumper, squares have such a nice neat staging sequence. For an unstable non-jumper pilot who cannonballs out of the wreckage and pulls the handle, offset in their harness and spinning like a pinwheel - I assume rounds are more reliable. Maybe I'm wrong?

The only rounds I've ever deployed were the paracommander variety and I felt like the opening completed in far fewer feet than any properly functioning modern square.

-Michael

[dpreguy 14]

PEP rounds we see every day lack some of the features of military rounds: Quick opening bands, elastic vent collars, anti inversion nets, slider, etc. The 24 foot belly reserves you mentioned ( I presume) had quick opening bands. Butler has the break cord ties around the apex lines and at the lower end of the lines to keep the lower lateral band even (compensating for a lack of an anti inversion net. )
The pilot rounds we see are pretty old school, except for the diapers. I would imagine that a ram air would (on average) have a quicker opening time because the rounds in common use lack the quick opening bands and vent collars.

Once they are open, they are (in my opinion) probably a safer bet for the 'untrained first time under a parachute' users, but the ram air folks are certainly disputing this.

I'm not really taking a firm position on ramair vs round except for the joy ride passenger. Even so, the old school rounds we pack all the time might consider the features the military has been using for years to enhance quicker openings and prevent mals. There is a tradeoff of course.
There always is. A quicker opening puts more strain on the canopy and the pilot and anti inversion nets add a packing difficulty. Butler's slider gizmos obviate the necessity of an anti inversion net.... and so on... Is simpler better? Good fodder for discussion.

[riggerrob 558]

Hackish, you started with an accurate assumption: at low airspeeds, you can deploy a round with a decent chance of survival. However, as airspeeds increase, rounds become less reliable .... less reliable than squares.
Round deployments and round malfunctions differ in many ways from squares.

My knowledge of rounds is limited because I only did about 70 jumps on rounds "back in the day," suffered 3 malfunctions on round mains and landed 3 round reserves. My last jump on a round canopy was in 1986 .... 30 years ago .... so my memories have faded.

However, rounds are less tolerant of higher speeds (more than 100 knots) and unstable openings. A key factor is keeping the skirt level during deployment. Diapers help keep the skirt level, as do deployment bags and sleeves.
OTOH If things start "going sideways" you develop an entirely new class of malfunctions known as "inversions."
Before (1980s) we fully understood the process, we called these mals "line overs" or "Mae Wests" but they are different from the "steering line overs" suffered by squares.
Inversion malfunctions start when fabric blows sideways during initial canopy inflation. If one side of the skirt blows across the centre-line and starts to inflate outside the opposite skirt, then an inversion malfunction starts.

[JerryBaumchen 1,047]

Hi Rob,

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However, as airspeeds increase, rounds become less reliable .... less reliable than squares.

OK, let's get serious. I will take any round canopy certificated under TSO C23b in the standard category ( some call this the 'high speed' category ) against any modern square available to the civilian market any day in a side by side test comparison on which one will stay together under high speed testing. I do agree that some rounds were built with very light material reinforcing, i.e., the Phantom series of rounds by National and any round built to the Low Speed Category of C23b.

Additionally, any round canopy built to the miltary's specs is even stronger. For surplus military canopies that were available to us 'back in the day,' you could not get a stronger canopy than a Navy 26 ft conical.

During the testing for the Strong StyleMaster rig, Dan Poynter got curious & tested an old, surplus 24 ft twill canopy under the Strength Test req'ment of NAS 804; it held together much to his surprise.

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However, rounds are less tolerant of higher speeds (more than 100 knots) and unstable openings.

Again, I completely disagree with this premise. See the above comments.

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entirely new class of malfunctions known as "inversions."

While an inversion is considered a malfunction, it is completely landable. You have merely turned the entire canopy inside out. It is still open at the same size as a normal opening, you're just facing in the opposite direction.

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"line overs" or "Mae Wests"

For surviveablility, I will take a line over on a round any day rather than the same malfunction on a square. I may break some/a bunch of bones on the round, but I will not be dead from the fast horizontal landing forces.

Again, just my $0.02 on this,

Jerry Baumchen

PS) I continue to say this: Just watch a square reserve land unaided and you might change your mind as regards body damage.

[riggerrob 558]

Enjoying this debate with Jerry ...
Hah!
Hah!
Military rounds are extremely reliable when packed in accordance with the military manual. However, when you remove: reefing ropes, spreader guns, quarter bags, etc. you reduce reliability.

Yes, I have landed two round mains that suffered inversion malfunctions.
The first steered weird because it was totally inverted, with the sleeve and pilot-chute hanging inside. I did a FIRM PLF in the grass beside the bowl. The mal was blamed on "sleeve slump" and a new, experimental packing method.
The second inversion straightened itself out and landed softly in a snow-drift. That T-10 lacked an anti-inversion net. The West German Army was frantically testing its next generation of canopies back then.

Both canopies suffered so many dozen small burn holes that they were scrapped (by the Canadian and West German Armies respectively)

I suffered both those mals during only 70 jumps on round mains.

Line-overs on squares can be eliminated by neat packing ... specifically keeping steering lines centre, rear.

As for square reserves landing hard?
Yes, we agree that small squares land hard. But when discussing PEPs, we try to limit conversation to 250 square foot reserve canopies that are docile and descend slowly.

As for speed: I was primarily referring to MIL SPEC static-lined canopies. During WW2, British paratroopers did not wear reserves because their X-type parachutes were so reliable when jumped from slow-moving DC-3/c-47. However, when the British Air Force updated (1960s) to faster turboprop transport airplanes, inversion malfunctions increased so much that they needed to add anti-inversion netting.

As for the US Navy 26 foot conical being the strongest round reserve?
Agreed!
Sadly, circa 1980, the US Navy started cutting the lines off surplus canopies. So we have not been able to buy military-surplus US Navy conicals for more than 35 years.
String's first few LoPo reserves were close copies of US Navy conicals, but reinforcing tapes have gotten weaker over the years.

The low point - strengths of round reserves - was circa 1980 - with flimsy Phantoms, Featherlites, etc. only certified in the Low-Speed category.
I wish all those Low-Speed round canopies would retire because they are not strong enough to be flown in anything faster than a glider .... and some modern gliders are certified for pretty fast top speeds!!!!!

Acid-mesh is a second excuse to retire Low-Speed PEPs.
Not wanting to waste money on bromocreasol and pull-testing tools is a tertiary excuse (third level).

[RiggerLee 61]

I think it's important to keep in perspective how these canopies were being deployed. You talk about jumps by the military. I'm assuming that these were direct bag static line deployments. Keep in mind that in that case the canopy is being stretched out in a big U cross ways to the wind as the body falls away till the break cord snaps. This is fundamentally different from a PC deployment with the canopy being deployed in line with the relative wind. How resistant the canopy is to some degree depends on the design. Longer canopies are harder to fully invert. And it stands to reason that a higher airspeed would be much more aggressive at trying to invert them. Static line canopies need an anti inversion net. I'm not convinced that a diaper deployed reserve needs one. A good diaper, full stow or three stow, diaper does a very good job of deploying the canopy. Their can be issues with asymmetry but that is also true to some degree with squares. Mary Ann had a big old friction knot on her reserve and I always suspected that it was relater to an unstable deployment after a spinning cutaway. Think of all the issues we've seen on main deployments from "bad body position". Granted on a 240+ canopy they probable would not be catastrophic. On the other hand the relatively minor partial inversions that clear and leave a few small burns low on the gore, the worst that you might expect with a diaper, are hardly noticeable.

Strength. I'd put a quarter bag deployed C9 up against any thing on the planet. The only way you can beat that would be if you put a reafing line on it. The body may be torn a sunder and fall from the harness in peace's but the canopy will not fail. The truth is that all square skydiving reserves are not really designed to operate above normal terminal velocity. Don't know about the aviator. We don't really test them that fast. Not in comparison to the military canopies. I think it's really irresponsible to put some of these canopies in some of the faster planes.

Lee

Lee
[email protected]
www.velocitysportswear.com

[Beatnik 2]

I completely agree with you Jerry. I have a lot of experience with both military and sport rounds during the last 15 years having accumulated over 500 jumps on them, plus experience with militaries and manufacturers on different projects.

Most malfunctions on rounds are not like the malfunctions on squares like you suggested. They are able to be landed and rounds can take a lot more punishment than a square can. I have yet to see high airspeeds with squares act as reliably as rounds do. Square canopies need a lot more modifications to their deployments to allow them to open reliably at high speeds than rounds. I have seen and packed the different configurations at work for squares many times and they are complicated compared to their round counterparts.

The number lower limb injuries may have been greater on rounds but they were less severe than the injuries that can occur from a square.

I am with you on rounds.

[pchapman 261]

To the thread in general:

There can be a lot of back and forth on this subject and I don't have the answers either. Everyone focuses on a different aspect of the situation and it is hard to reconcile which are typically more important. Do you care more about extra high speed and low level, or moderate speeds & altitudes? And at what price level? Is one comparing a typical round vs. a square, or the very best rounds against a square?

Throwing around some arguments, really quickly and without a final answer:

Sure, C-9's are really tough. Yeah but how many are put in new pilot rigs? And who doesn't want a diaper these days? Well, sometimes they can be added but that's for another day. And if deciding whether "rounds are better", what about wimpy Phantoms & Phantom Aerostars out there? 140 kts max, and low recommended weights. And TSO C23b testing that's pretty sketchy. Even the Preserve I and III (not the V), common bailout canopies, are TSO C23b, 150 kts max and 220lbs or less. That's no better speed than PD reserves, which usually have higher weights like 254lb allowed, and a more trustworthy TSO with more margin. Strong Lopo's at least got upgraded to C23c Cat b, 150kts, 254 lbs

Sure there's the pricy Butler high speed rounds but you don't see many around. Or some GQ bailout rigs use the a GQ T4000 Aeroconical good to 180 kts! Yet a bailout rig with a square will likely also cost more than one with a wimpier round. Should one expect high speed opening from fast aircraft, or will the pilot typically have time to wait a couple seconds during which high speeds will quickly be reduced?

So rounds are typically lower speed than squares yet some rarer rounds can be higher speed.

Is a temporary inversion really acceptable? Burning holes in a reserve is so 1970s; hopefully with no LLB damage. How likely are deployment issues when dealing with diapered rounds? The information available always seemed vague to me.

No time for better arguments so I'll leave it at that.

[councilman24 36]

I routinely recommend the higher rated butler chutes and have anout 10 that i service.

I'm old for my age.
Terry Urban
D-8631
FAA DPRE

[Spooky52 0]

NO! That is a sure way to hurt them. They are not familiar with the characteristics of a square and more than likely will not be ready for the landing. I see lawsuit written all over that scenario. Yeah, yeah, waivers, etc. blah, blah, blah. I'm sure you are aware that waivers are only good as toilet paper.

If you know how many guns you have - you don't have enough!

[JerryBaumchen 1,047]

Hi Walt,

My apologies for not responding until now.

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The 24 foot belly reserves you mentioned ( I presume) had quick opening bands.

No, the 24 ft twill canopy did not have quick opening bands.

The guy at 400 ft with the pilot chute deployed a 26 ft Navy conical, no quick opening bands.

Just to clarify this,

Jerry Baumchen

[dpreguy 14]

Wow, those were some fast openings for non-quick opening band canopies! I have never seen a 24 foot belly parachute without the QOB's. The one's I've seen were military paratrooper surplus. Al were so equipped.

[riggerrob 558]

Yes Beatnick,
We can agree that faster (than 200 knots) warbirds deserve MIL SPEC parachutes certified for more than 200 knots.

Next question: where are you going to find MIL SPEC parachutes?
.... considering that Crown Assets Disposal started cutting off lines circa 1980?
Yes, Softies and Strong PEPs offer new-production, MIL SPEC C9 canopies as options, however neither use MIL SPEC quarter bags. Softie offer C9 with Butler (Type 4, full stow) diapers while Strong offers them without diapers????? Odd since Strong was one of the first to manufacture sport reserves with diapers and has been advertising how much more reliable diapers are. I don't understand Strong's logic????

We all know that free-deployed (Type 1 with all suspension lines stowed in the pack tray) rounds suffer too many mals and the mal rate increases with airspeed. Diapers help up to 200-250 knots. Since rubber bands become unreliable at faster deployment speeds, you need a MIL SPEC quarter-bag, reefing ropes, spreader guns, etc. I have not seen a quarter-bag going on 20 years. And I gave never ever seen reefing ropes on a man-rated canopy. MIL SPEC ejection seats have all those deployment gadgets, but they are not available to civilians.
So that gets us back to the original question of how to equip warbirds flying more than 200 knots????

If you have seen Butlet's video comparing a C9 versus one of Butler's slider-equipped rounds (sled, ejection seats, etc.) you would immediately how to the greater wisdom of Saint Butler!!!!
Sorry, I got carried away by Butler's engineering genius.

So faster than 200 knots, we need a staging device (diaper, quarter-bag or freebag) and a slider.

That narrows our decision to Butler's HX series rounds or squares.

As for why the Aviator is only certified to ??? knots .... our old B-25 drop-plane would only fly 205 knots with the bomb-bay doors open. After we had completed all the certification drops, George Galloway (Precision) told us to keep adding weight until we tore a canopy. We ran out of daylight and lead weights before we tore a P124A-280 canopy. I was too tired to count by the time we exceeded 400 pounds. IOW we never tore a P124A/Aviator.
Military tandem reserves have been MIL SPECed to much heavier weights and much faster airspeeds, but soldiers refuse to share their data with civilians.

As for the arguement that damaged rounds land better than damaged squares .... that is so 1970s .... I have landed 2 damaged rounds and more than a dozen damaged squares. That is out of 70 jumps on rounds and more than 6,000 jumps on squares. All of those damaged squares were first-generation (1980s technology) tandem mains. First-generation tandem mains have all retired.

Bottom line debating the relative merits of landing damaged canopies is an admission that you are jumping unreliable, out-dated gear.

[RiggerLee 61]

Actually Quarter bags are quite common, at least around here. Their seem to be BA-22's all over the place. Their just seem to be a lot of war birds around. Cavanagh Flight Museum seem to have a scores of them. And oddly enough some times you seem to be able to find new ones. A few years ago John Storrie some how scored like a whole container of them. It was a big crate packed full of like a dozen of them, BA-22's, wrapped in plastic brand new, never seen service. Theirs shit out there. Tom found an MC-4 intact. So in some way or other rigs do from time to time escape the military with out being demilled. I don't know by what route this occurs but it does seem to happen on occasion.

Lee

Lee
[email protected]
www.velocitysportswear.com

[betzilla 56]

Hiya Jerry!

1. zero so far...

2. nope

3. Several times, I've recommended against buying squares if there's any chance a non-skydiver will be wearing the rig. I do have a handful of skydiving customers who are learning aerobatics, and have asked about buying rigs with squares. I'm happy to sell them in that case (though I usually have to explain why a PDR 126 might not be a great idea, haha), but none of those people have purchased PEPs just yet.

There was one customer who was a very experienced skydiver who wanted an Aviator to wear in his new experimental plane. But the lead time wasn't short, and he didn't want to wait as long as it would take to get one. Interestingly, he opted for a round in his Softie, even when I told him he could get a PDR in it. Go figure.

[JerryBaumchen 1,047]

Hi Rob,

Quote

So faster than 200 knots, we need a staging device (diaper, quarter-bag or freebag) and a slider.

That narrows our decision to Butler's HX series rounds or squares.

Are there any certificated square canopies, available to the civilian market, that are rated at 200 knots? I am asking because I do not know of any & maybe you do.

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Bottom line debating the relative merits of landing damaged canopies is an admission that you are jumping unreliable, out-dated gear.

'landing damaged canopies' is a play on words. I specifically used a line-over type of malfunction. And this from the guy who despises lawyers.

To determine body damage/survivability we need to be comparing types of malfunctions specifically. Think of a 12" hole in a round canopy at 6" above the skirt vs a 12" hole 6" from the apex. And then think of a 12" hole in the bottom of skin at the tail of a square canopy vs a 12" hole in the top skin at the nose of an end cell.

Jerry Baumchen

PS) And any discussion who may or may not have had or not had any malfunction on any main canopy is not a part of the subject of this thread. Lets not waste bandwidth.

[riggerrob 558]

Narrowing bandwidth .....
Tandem manufacturers need to prove that reserve canopies will survive opening at "tandem terminal" which is around 200 knots.

[Beatnik 2]

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Next question: where are you going to find MIL SPEC parachutes?
.... considering that Crown Assets Disposal started cutting off lines circa 1980?

Crown assets has been removing lines since at least the 1960's. At least that is what one of the riggers that I apprenticed under said and since he was a rigger from the mid-50s for the military and was of the people doing it I was trust his word. But that is an aside.

Finding MIL SPEC C9's is not that difficult. I have donated four parachute systems to different warbird projects in the country over the last few years. All of which were C9's. Also important to note none were stolen or came from Crown Assets, all obtained legally. I do little work for the Canadian military with the parachute world other than being a tandem examiner for them and someone that does further professional development but that is side projects from my real job. But to your question, I do work with several companies that provide to the militaries outside of Canada. Obtaining these parachutes are not as difficult as you thinking have had several new C9's over the last few years. It is no different than getting quarter bags, SET-10s, MC1's (different variations, MC4's, etc. I unpacked hundreds of these canopies at a place I was helping out last year.

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Military tandem reserves have been MIL SPECed to much heavier weights and much faster airspeeds, but soldiers refuse to share their data with civilians.

The tandem systems that the Canadian military uses are UPT Sigma's. They are exactly the same as the ones being jumped at dropzones throughout the world there is no difference. I don't have details of all the militaries in the world. Could you share what systems you are referring to? Some of the troop systems might be rated for higher but it would depend on what configuration they are in. They still don't use them in as high as airspeeds that they use rounds in.

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As for the arguement that damaged rounds land better than damaged squares .... that is so 1970s .... I have landed 2 damaged rounds and more than a dozen damaged squares. That is out of 70 jumps on rounds and more than 6,000 jumps on squares. All of those damaged squares were first-generation (1980s technology) tandem mains. First-generation tandem mains have all retired.

You can call the argument what you will but it doesn't make it less true. The information that you provided doesn't make it significantly significant data that can be relied upon but it can make it your opinion. For the information to be relevant you would need to compare similar damages and gather information. Rounds can withstand far more damage than a square can and still be a safe canopy. I realize that you have more jumps than I do and I won't argue with your personal experience but I have worked a lot in test and evaluation plus I am getting more formal education (a whole programme and degree regarding it) in the aerospace industry within this field and have an idea. It doesn't all come down to jumps. But I digress this can be something we can debate sometime in person if we ever run into each other again. It doesn't need to be discussed here on a open forum.

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Bottom line debating the relative merits of landing damaged canopies is an admission that you are jumping unreliable, out-dated gear.

You seem to jump to conclusions a lot. It is not an admission at all. Malfunctions on rounds are different than squares and many malfunctions are landable. But by your statement then landing a ramair that is damaged would be unreliable and out-dated gear.

I have lots of gear in my personal collection of parachutes that you could call outdated. I have an old candy-strip from 1952 that I have jumped, which is out-dated by any stretch. But just because something is out-dated doesn't mean that it is unreliable or should be grounded. The two are not synonymous.

[Beatnik 2]

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Tandem manufacturers need to prove that reserve canopies will survive opening at "tandem terminal" which is around 200 knots.

Your math is a little out.

The conversion factor for miles per hour to knots is: 0.86897624190816

The equation would be knots = miles per hour X conversion factor.

Assuming tandem terminal is 170 mph.

knots = 170 X 0.86897624190816 = 147.7259611243872

They are approximately 52 knots short of the 200 mark.

[JerryBaumchen 1,047]

Hi Rob,

Quote

Tandem manufacturers need to prove that reserve canopies will survive opening at "tandem terminal" which is around 200 knots.

The thread title is: PEPs with square canopies

Is anyone anywhere in the world actually putting a tandem reserve canopy in a PEP?

Ridiculously, I was hoping that would be the issue to be discussed.

Jerry Baumchen

[pchapman 261]

Again to throw some quick numbers into the mix:

This stuff isn't relevant to the original question (sorry Jerry!), but does provide background to the argument about rounds vs. squares at high speed.

Some of the UPT / CPS military tandem-style reserves are good for 180 kts, at values like 550 to 650 lbs [VR 421, HR 360, HR 400].

That's normally up to 25,000'. One variant with a reefing drogue controlled slider can do up to 35,000' -- a tougher situation even if the 180 kts is unchanged. Many of the military tandem reserves have special high speed freebags too, beyond "our" typical single safety stow.


As for the military's tough single reserves for solo jumpers, things like the UPT/CPS OR series go from 360 ft sq. down to a minimum of 260 ft sq (still big!) with weights of 325 to 450lb. They are only certified to 150 kts -- like your typical PD civilian reserve.

I have no idea what else is out there; I just read some brochures on the web.

(And I don't recall what civilian Sigma VR-360 reserve is rated to.)

So it is pretty tough to find high speed square reserves even among the military -- NOT up to 200 kts -- although they can take some heavy loads and high altitude openings.

[riggerrob 558]

Limiting bandwidth ....
Please limit this conversation to current-production chutes that are legally available to civilians ... nothing smuggled out the back door of a military warehouse.

[riggerrob 558]

No, I have not packed a tandem reserve into a PEP.

The closest I have come was packing a pair of Para-Flite 340 military freefall reserves into Butler long-back PEPs. Even 340 square feet and Dacron lines did not "bulk-out" those 40 inch (1 metre) containers, so I recommended that in the future, Mr. Butler limit squares to 20 (ish) long, back type containers.
We sold those huge canopies to a pilot that "weighed more than 254 pounds" and no civilian canopies were certified for his weight.

However, if a 300 pound pilot asked for a PEP, I would be sorely tempted to sell him a Precision or Racer tandem reserve.