Test Jump: 2 canopys out

[Hooknswoop 19]

Report from a 2 canopy out test jump w/ disproportionately sized canopies w/ a Stiletto 97 playing main and a Safire 189 playing reserve. The Stiletto was deployed first.
Deployed a Stiletto 97 (got buzzed by the otter) and left the brakes stowed. Deployed a Safire 189 (would be a 174ish if measured the same way as the Stiletto) Switching the Safire for the PD-170 would have been a pain in the butt and I got lazy. They immediately downplaned, with the stiletto in front. I let it go at that, thinking I would ride that for a while, but after 4-5 seconds of downplaning, the Safire came around so that they were in a side by side configuration w/ the Safire on the left. The Stiletto immediately tried to eat the Safire, turning into the Safire and collapsing the left side of the Stiletto. It was turning to the right, at a decent clip, with no input from me. It was definitely not in a stable configuration as the Stiletto kept turning and collapsing the left side, backing off and running back into the Safire. Then it got worse. The Stiletto wrapped around the right side-lines of the Safire and the whole mess started a VERY fast spin to the right, all w/o input from me. I rode this configuration for quite a while at a very high decent rate. Eventually as the Stiletto got more entangled w/ the Safire, it got worse, w/ the Stiletto collapsing and re-inflating "explosively" it was loud and uncomfortable. At that point I became concerned that the canopy(s) would be damaged, so I released the Stiletto and it entangled w/ the lines of the Safire on the right side, causing a fast turn to the right. I then released the Safire.
I have flown a Safire 189/PD-170 combination twice. Once in a side by side for several thousand feet with absolutely no problem and on the second time I attempted to put them in a downplane. I could get them to downplane, but as soon as I released the riser, they would go back into a side by side, whether the brakes were set on either canopy or not. The similar sizes resulted in a land-able, stable 2 canopy out situation. Conclusions:
This was only 1 test, but I believe it is obvious that two canopys that are so dramatically different will not be stable enough to land. The canopys behave as I expected them to (except for the initial downplane, which wasn't land-able either). At no point past the inflation of the Safire, was the two canopys out situation land-able. I am defining land-able as being able to land w/o injury or death. For most of the test, I believe the landing would have been fatal.
I believe a two canopy out from a low pull with the AAD firing is a more likely scenario than being unconscious, the AAD firing and landing unconscious under the reserve. I have seen 7 or 8 2 canopy out situations from low pulls and have only heard of 1 jumper landing unconscious under her reserve, but she did not survive the incident either way, either from being killed from the initial impact or hitting a rock on landing. There was an incident of a jumper landing unconscious under canopy from a riser choking them, but I don't know if it was their main or reserve. I think everybody thought the person was dead and almost a minute later the person sat up and took a deep breath, scaring the hell out of everybody and was OK.
I think a small main/large reserve combination is not the way to go. If you do not want a small reserve, don't get the small main. That is the price you pay for a small main, or be willing to accept that in a 2 canopy out situation will have a good chance of killing you. If you do have a small main/large reserve combination and an AAD, be aware that a low pull/AAD misfire will put you in a dangerous situation and cutaway the main immediately to prevent an entanglement, as the situation will get worse.
All this rambling is not set in stone, and is definitely not meant to offend anyone. I would hope this post generates a discussion that is informative and sticks to the topic. I will answer any questions from any details I may have left out. The end goal is for everyone to learn.
Derek

[Beachbum 0]

Very informative .. to me, at least. Thanks so much for putting yourself at risk for our benefit! It sounds like there was a point where you could have cut away the main cleanly if you hadn't been testing/playing with the combination (while in the initial downplane)?

[PhreeZone 15]

Derek,
Just a question, what was the difference in line length between the canopies? The reason I'm asking is because I know on some of the X-braced canopies the lines are longer and the taper is less radical. Would the difference in line length allow for the canopies to have the end cells touch in stead of the canopy wrapping in the lines of the other canopy?
Also on delpoyment of the Safire did you pop the brakes to allow the canopy to fly faster and keep up with the Stiletto or leave the breaks stowed to keep both in brakes? If you left the brakes stowed, in your opinion would have releasing the brakes help the larger canopy fly in a more stable configuration?
Cause I don't wanna come back down from this cloud... ~ Bush

[Hooknswoop 19]

Yes, I could have cutaway the main cleanly during the initial downplane.
Derek

[Hooknswoop 19]

The Stiletto has shorter lines than the Safire. Generally the smalleer the canopy, the shorter the lines. I left the brakes stowed on both canopys. Releasing the brakes on the Safire would have probably helped, but it is 0P, so it was probably flying close to the speed of an F-111 in full flight with the brakes stowed. I was origanally going to switch out the Safire for a PD-170 for a closer Main/Reserve dual deployment simulation, but that would have involed changing several sets of risers. As it was it took a little while to set up and will take even longer to clean up.
Derek

[PhreeZone 15]

Quote

Releasing the brakes on the Safire would have probably helped, but it is 0P, so it was probably flying close to the speed of an F-111 in full flight with the brakes stowed.

I'm not under standing this one.... The canopy material has nothing to due with how fast the canopy flies. A F111 canopy can do CReW with a ZP canopy of the same loading and they fly at the same forward speed. A new or fairly new reserve has such low porsity that it will act like ZP for a few jumps.
By having the brakes stowed it would simulate having the brakes on a Reserve stowed too, a Safire SHOULD have forward speed similar to a reserve of the same size....
Feel free to correct me if your opinion differs.....
Cause I don't wanna come back down from this cloud... ~ Bush

[Hooknswoop 19]

The Safire is semi-elliptical, has a higher spect ration than a 7 Cell reserve, and has thinner end cells than center cells. I think a Sabre 170 ios a PD 170 made of 0-P and having jumped both, the Sabre is faster in braked stowed, forward flight. In my experience, I can blow through brand new F-111, not a lot, but it does let air through. I can't blow through brand new 0-P, not even a little. So i think the Safire in brakes is faster than a same sized F-111 reserve in brakes.
Derek

[Zennie 0]

Lots of good info Derek. Thanks! Didn't realize that's what you had planned on the ride up today.
That's actually a very good experiment, because my downsizing plan was going to include maximizing my reserve size. I think I"ll have to reconsider that in light of your test.
Do you have any sense for what a rough maximum difference in square footage would be to not have this phemonenon so readily appear? For example, my current setup is a Jedei 136 with a PD 160 reserve. I wouldn't think these would be so far off as to cause that sort of problem (at least not to an unusual degree) but I could be wrong.
"Zero Tolerance: the politically correct term for zero thought, zero common sense."

[PhreeZone 15]

Ok... I see what you are saying now, I was reading your statments like the Safire in Brakes was the same as a Reserve with the brakes popped.
Was the Stiletto surging at all during its side by side flight or was it maintiaing a constant speed?
Cause I don't wanna come back down from this cloud... ~ Bush

[Hooknswoop 19]

I couldn't say that "as long as your main are within XX # of square feet of each other, they will be OK". Only that the closer in performance they are, they more stable a 2 canopy out situation will be and the larger the difference in performance between the two, the less stable. For hard #'s the Safire 189/PD-170 combination workes out great and the Stiletto 97/Safire 189 combination did not. Anywhere in between and your guess is as good as mine.
Ya great experiement, now I have mount parachute sitting on the floor next to me. At least Kelli untangled everything for me :-) I inspected everything, no damage. But it will take a bunch of work to get everything back to the way it was.:-)
Derek

[Hooknswoop 19]

Actually, I was saying that the Safire with the brakes still set was probably only a little slower than a reserve (at the same wingloading) in full flight. I think the results would have been even worse w/ the Pd-170 replacing the Safire 189.
The Stiletto was surgining, stalling, collapsing, entangling, and re-inflating while they where in the side-by-side. It caused a continual right turn, which increased my decent rate to the point that I couldn't have safely landed in that configuration.
Derek

[Zennie 0]

Quote

Ya great experiement, now I have mount parachute sitting on the floor next to me.

Heh. Well like most great experiements you wind up with a big mess but a lot of good information!
"Zero Tolerance: the politically correct term for zero thought, zero common sense."

[riggerrob 558]

Thanks for exposing your ass to danger so that I don't have to!
Unfortunately, you only got crude data, because you were operating under a popular misconception.
The popular misconception is that modern reserves handle similar to modern mains. NOT!
The only modern main that handles like a reserve is a rectangular, 7-cell Triathlon.
Fabric choice only makes a minor difference in handling. New 0-3 cfm reserve fabric flies almost the same as the 0 P fabric mains are made of.
Aspect ratio is the biggest difference. Seven-cell reserves glide steeper, require more toggle movement to flare and have a smaller sweet spot during the flare.
Planform (rectangular vs. tapered) mainly affects turning characteristics. Tapered canopies turn more "vigorously."
And to clarify an earlier posters point. When Performance Designs designed the Sabre, they did not simply "re-skin" a PD-170. The Sabre introduced new fabric, new air foil sections and new line trim for more docile handling. Compare the open nose on a PD series to the over-hanging nose on a Sabre. PD knew that big people were going to overload Sabres, so they designed Sabres to land better than their PD series.
I am currently jumping a Sabre 135 with an Amigo 172 reserve. Even when I transition to a 120 main this summer, I have no intention of changing reserves, because I don't expect to land - my 190 pound ass - softly under a reserve any smaller than 170. Sorry, folks, I will have to see far more objective data or a new generation of reserves before I will jump a tiny reserve.

[riggerrob 558]

Thanks for exposing your ass to danger so that I don't have to!
Your Stiletto 97 was doing some pretty scary stuff!
Unfortunately, you only got crude data, because you were operating under a popular misconception.
The popular misconception is that modern reserves handle similar to modern mains. NOT!
The only modern main that handles like a reserve is a rectangular, 7-cell Triathlon.
Fabric choice only makes a minor difference in handling. New 0-3 cfm reserve fabric flies almost the same as the 0 P fabric mains are made of.
Aspect ratio is the biggest difference. Seven-cell reserves glide steeper, require more toggle movement to flare and have a smaller sweet spot during the flare.
Planform (rectangular vs. tapered) mainly affects turning characteristics. Tapered canopies turn more "vigorously."
And to clarify an earlier posters point. When Performance Designs designed the Sabre, they did not simply "re-skin" a PD-170. The Sabre introduced new fabric, new air foil sections and new line trim for more docile handling. Compare the open nose on a PD series to the over-hanging nose on a Sabre. PD knew that big people were going to overload Sabres, so they designed Sabres to land better than their PD series.
I am currently jumping a Sabre 135 with an Amigo 172 reserve. Even when I transition to a 120 main this summer, I have no intention of changing reserves, because I don't expect to land - my 190 pound ass - softly under a reserve any smaller than 170. Sorry, folks, I will have to see far more objective data or a new generation of reserves before I will jump a tiny reserve.

[Snowflake 0]

Thats awesome.....Thanks for the info
JG

[Hooknswoop 19]

Riggerrob- your'e right about the Sabre, thanks.
As for "operating under a popular misconception", I know that the Safire 189 is not a great represenation of a reserve because it flys faster, but it made for a more stable configuration than a PD-176R or a Tempo 170 would have, so I think the results would have been even worse w/ a real reserve. If the Safire had been been replaced w/ a canopy flying slower and steeper, there would have ben a larger disparity between canopys and they would have entangle faster/worse. So the test data still stands, Little main/Large reserve=big trouble in a 2 canopy out situation.
Anyone have a larger reserve they will send me for another test jump? I would be willing to test ALMOST any configuration.
Derek

[MarkM 0]

Thanks for the testing Hoops.

[rgoper 0]

derek:
am i safe with the 170 main/193 reserve config? i'm assuming i am, or you would have brought it to my attention. thanks for being a test pilot, i probably would have never learned of this. i understand you did this for an experiment, but in the training we recived at sdsl, we were instructed to fly tallest, most dominant, or if unmanageable, (downplane/entanglement) chop main, and fly reserve. right....hope so, that's my plan. thanks for the data.
Richard

[PhreeZone 15]

Derek, You might want to contact PD or PA about this. Both have reserves hooked up as mains and they might be interested in some of the data you could provide them. Or they might have already done some of the test jumping themselves and could save you some wear and tear on your canopies.
Cause I don't wanna come back down from this cloud... ~ Bush

[Hooknswoop 19]

170/193 combo should be pretty compatible. As for handling two canopies out, best advise is:
Bi-plane - For the canopies to stay in a bi-plane the main would have to be in front, don't release the brakes on either canopy, stear the lead canopy using rear risers, plf for landing. Cutting away the main may result in an entanglement.
Side-by-side - If you can determine if the main will clear or it's not stable and not flying nicely with each other, cut-away. Otherwise, steer the main (or dominate canopy) with the rear risers gently, and plf for landing.
Down-plane - Cutaway.
The reason we taught you to land the side-by-side is because all the student gear would fly a side-by-side ok and we didn't want a student to cutaway from a side-by-side and have it entangle. We wouldn't expect a student to determine if a side-by-side could be cutaway cleanly.
Derek aka. Hook

[Zennie 0]

Brakes stay stowed on a side-by-side as well correct?
"Zero Tolerance: the politically correct term for zero thought, zero common sense."

[Hooknswoop 19]

I don't think PD or PA want to get involved, with the legal atmosphere in this country. If they where interested, they would have done the jumps, and if they have done the test jumps, they would have released the information. I did it to prove what I already knew, in a 2 canopy out situation, the closer the canopies are in performance, the more behaved they will be and vice versus.
Some people that jump a small main/large reserve combination are well aware that a 2 canopy out situation would be bad, but feel that they are more likely to land unconcious under there reserves, or want the added safety margin that a big, slow reserve affords them. I did this to demonstrate to those with the small/large combo that didn't believe that the canopies wouldn't fly together that they won't. Besides, it was one hell of a ride, and I finally got to fly that Furry 220R. Nice reserve. Freebag was less tha 100 ft away when the reserve was fully open and flying.
Derek

[Hooknswoop 19]

If they are flying together in a side-by-side, either don't change anything or cutaway if it will clear. Releasing the brakes on the slower canopy MIGHT stabalize a slightly unstable configuration, or might make it worse.
Just like any other malfunction the best course of action is to avoid the malfunction in the first place. Watch your altitude (this will prevent a 2 canopy out situation if you pull low and have an AAD) and close you container and route your PC bridle correctly. If your PC hangs up (either mis-routing or too tight of a closing loop) and you fire your reserve, it is possible that the reserve freebag leaving will give the main conatiner more room, allowing the main to deploy= 2 canopies out.
Hook

[Phil 0]

...so if you have a hard pull or similar problem, cutaway no matter if the main is out or not. That way you won't run the risk of getting 2 chut's out.

[riggerrob 558]

Phil,
A hard pull implies that none of the main pilotchute is out.
Is none of the main is out, go straight for the reserve ripcord.