Stalling your canopy

[billvon 3,058]

>What is "beyond" a stall?

Flying the canopy backwards. We used to do that on the DC-5 student canopies we had back in '91.

[diablopilot 2]

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Flying the canopy backwards.

I would say that is also stalling.

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You're not as good as you think you are. Seriously.

[Flyer2Diver 0]

Article on what defines a stall.

The entire wing doesn't necessarily stall at the same moment. On most wings, the shape is not uniform over the span (eliptical canopy, brake lines/risers distorting the shape, etc.) - this can manifest itself as a mild/docile stall as only some portion of the lift is lost.

I think the distinction we're drawing here is full stall (where the canopy folds up like a sideways taco and stops flying) and partial stall (where it keeps its shape and continues to fly, but significant lift is lost).

I believe the term "deep stall" is most often used relative to t-tail aircraft - it is possible for the elevator to be rendered ineffective by the turbulent airflow from the stalled wing at extreme angles of attack, making recovery difficult to impossible.

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30005KT 10SM SKC 23/05 A3006

[pilotdave 0]

Deep stall also refers to canard aircraft, which supposedly can't stall. But if the pilot manages to get the angle of attack so high the canard stalls, it's usually not recoverable. Same idea.

Dave

[gdmusumeci 0]

Disclaimer: I've done this, but my jump numbers are low. You should seek further training from your instructor(s) before you take any of my advice.

I've stalled a Sabre2 210 (loaded at about 1.1) by taking two wraps on the toggles, and I learned a lot about how canopies stop and restart flight. I'd tried on several occasions before to stall without taking a wrap on the brake lines, and I couldn't really get the canopy to do anything but fly "mushy." Taking a wrap on the toggles really does quite a bit. At some point the wing seems to think twice about this flight thing, and the end cells collapse and start to curve inwards. The next steps happen very, very fast: once the center cells decide to stop flying, that's it, they STOP. The canopy then starts to fold up on itself, there's a strong feeling like you're falling backwards -- the end state feels like falling quite fast while towing a huge nylon streamer.

You must recover smoothly from the stall and let your hands up absolutely evenly. I didn't do that part quite right, and induced a quite terrifying spinup as half the canopy inflated, the other half stayed deflated, and about a dozen twists got put in the lines. I very clearly remember thinking "well, this one's fucked, where's that red pillow?" before checking altitude and starting to fix it (please note that I initiated this maneuver at about 6000' and was fully recovered by about 5000').

What scares me the most about this is that I can easily envision a case in which your hands are pinned by the wrapped line and it's difficult to reach the cutaway handle. That would be a bad way to go in; although I haven't tried a rear-riser stall yet, I plan to do so this weekend if I get a chance.

Just my two cents.

[quade 4]

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Depending upon who you ask. There seems to be a difference of opinion as to what a stall is.

The word "stall", as it pretains to aerodynamics is pretty well defined -- exceed the critial angle of attack and the wing is stalled.

Does that mean you've lost control -- not nessasarily. Can you increase the AoA further with more deleterious effects -- probably. I'd say causing the canopy to collapse is -well- beyond simply stalling the canopy.

quade -
The World's Most Boring Skydiver

[murrays 0]

It is wa-a-a-ay more fun if you stall your canopy with a friend!

In the old days when canopies all had dacron lines and were lower aspect we used to do this quite a bit. We called it a trashplane. Sometimes they downplaned very stable and other times bucked and thrashed around violently.

This was my buddy Angus Smith and I at Gananoque ON in about 1985 or so.

--
Murray

"No tyranny is so irksome as petty tyranny: the officious demands of policemen, government clerks, and electromechanical gadgets." - Edward Abbey

[diablopilot 2]

Now THAT is what I call -beyond- a stall.

Care to do it again? I've got a Xaos 27 cell with your name on it!

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You're not as good as you think you are. Seriously.

[nael 0]

Well, I spoke to my instructor about rear riser stalls, and he said it'd be ok to attempt them. I went up, tried to stall it with the toggles one more time, of course, no luck, so went to the reas risers, pulled them down as far as I could (which incidently seemed to lift me up more than pull them down!) and it still wouldnt stall. It didnt like it, flew like crap and bucked around a bit, but no stall.

The good news is, my instructor watched me try this for 2 jumps today, and told me to forget it cause I wasn't going to be able to stall this canopy. So, I'm jumping my own canopy on sunday (depending on how my jumps tomorrow go), and I'm sure as hell going to stall it.

Thanks again for all the advice.

www.TerminalSports.com.auAustralia's largest skydive gear store

[murrays 0]

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Now THAT is what I call -beyond- a stall.

Care to do it again? I've got a Xaos 27 cell with your name on it!

Is it packed in a cutaway rig?

Here's another one for ya JP! PD150 9 cell. I haven't done this yet with my Sabre2 135...but I will someday.

--
Murray

"No tyranny is so irksome as petty tyranny: the officious demands of policemen, government clerks, and electromechanical gadgets." - Edward Abbey

[mr2mk1g 10]

Your first pic is like a CRW Mr Bill! That's funny.

[nael 0]

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Here's another one for ya JP! PD150 9 cell. I haven't done this yet with my Sabre2 135...but I will someday.

I love how calm the guy looks in that photo! He's loving it.

www.TerminalSports.com.auAustralia's largest skydive gear store

[dmbale 0]

I jump a Spectre at a similar wingloading and cannot stall it, even with taking a wrap. I have tried several times at 3K or more to do this and it just doesn't happen. The best I have been able to do is to get a little bucking from the canopy.

[diablopilot 2]

Somewhere I have a shot of my under my 88 Xaos like that. (Well I think it's a riser stall, but.....)


No I meant let's do the "stall plane" I've got a cutawya rig for ya if yer skeerd......

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You're not as good as you think you are. Seriously.

[mattjw916 2]

lol, thanks for giving me something to try this weekend (after talking to my coach AND with plenty of altitude )

GREAT PICS!!!

NSCR-2376, SCR-15080

[ianmdrennan 2]

Great shots Murray!!!

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I haven't done this yet with my Sabre2 135

I know what TK would say to that

Hope all is well.

Stay safe.

Blues,
Ian

Performance Designs Factory Team

[murrays 0]

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Somewhere I have a shot of my under my 88 Xaos like that. (Well I think it's a riser stall, but.....)


No I meant let's do the "stall plane" I've got a cutawya rig for ya if yer skeerd......

I would be scared sh*tless!!

That trashplane was actually the last one I ever did. We started it under 2000' and shortly after the photo was taken the violent bucking resulted in me being briefly engulfed in Angus's canopy...white fabric and lines everywhere. I popped out of it but was pretty lucky not to have gotten my camera, which was duct-taped to my left foot, entangled as the shutter release jack was broken off so it had been involved with some lines. We were at about 1400-1500' at that point. Not a good altitude to get wrapped. (I should have included this bit of information in my original post)

It was done under 170-180 sq. ft. 7 cells..I can't imagine the violent reaction you might get under a Xaos type canopy. Wild!

--
Murray

"No tyranny is so irksome as petty tyranny: the officious demands of policemen, government clerks, and electromechanical gadgets." - Edward Abbey

[nael 0]

I jumped my own 170 yesterday for the first time (beer, I know!) and stalled it really easily. I was watching it buck a bit one minute, and about 2 seconds later the end cells were touching and I was falling. Scared the hell outta me even though I was expecting it! I was at about 5k when I did this by the way - just in case anyone tries it low!

I've stalled it about twice on each jump I've done on it since, just so I can really get that stall point in my head, plus it is kinda fun.

www.TerminalSports.com.auAustralia's largest skydive gear store

[murrays 0]

Good for you! It's good to know what a stall feels like and how to recover. Have fun playing with that new canopy up high

--
Murray

"No tyranny is so irksome as petty tyranny: the officious demands of policemen, government clerks, and electromechanical gadgets." - Edward Abbey

[pchapman 279]

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>What is "beyond" a stall?

I'll take that as a challenge! There's plenty of fun stuff when one explores beyond the stall point. For example, a number of variations on the stall:

1. The canopy stays inflated but descends almost vertically.
This may be what is known in paragliding as going 'parachutal'. A ram air canopy can have a very high, stalled angle of attack that is essentially stable. The airflow is separated over much of the top of the canopy but the canopy stays inflated. Looking at Parafoils sinking the last ten feet into the tuffet, it looks like they may be in that mode of flight.

2. Canopy horseshoes backwards, with the end cells moving aft.
A very common behaviour as a canopy stalls. While the aerodynamic stall will have something to do with the shape the canopy assumes, the shape must also result from the long distance the brake lines are pulled down, at a time when when the canopy has little inflation pressure.

3. Canopy horseshoes forwards, with end cells moving forward and touching.
I've done this using rear risers to stall a student canopy like a Manta. Even after letting go of the risers, the canopy may stay in this state, with the end cells bumping each other as they try to regain forward flight. Needed a pump on the brakes to unstall the canopy.

4. Ball of garbage.
Really deep into a stall aerodynamically, brakes pulled a long way down, and the chute completely collapsed. I've done it on a Stiletto 120 at 1.4 wing loading but no higher wing loading yet.

5. Flying backwards.
The canopy is flying down and slightly aft. The glide angle backwards is very low, but there is backwards motion. The canopy retains its shape, the cells might be deflated because the nose isn't catching much air. I understand some have done formation flying in this state. ('Stalled CRW' -- but I don't know about any actual hooking up.)
I get the impression that F-111 canopies tend to be better for doing this. But other canopies may work well. Eg, it works really well on a Sabre 135 when the brakes are set, and one stalls with rear risers. That combination provides a nice downward curvature to the trailing edge of the wing, that seems to work well as a "leading edge" when flying backwards.

6. Helicoptering.
Canopy descends essentially vertically, while inflated. It spins with wings level, so it is rotating about the yaw axis, and resembles a flat spin in an aircraft. One side of the wing is still flying, while the other is stalled but inflated. It can be done very well by paraglider aerobatic pilots. Descent rate is very low. On parachutes, I've vaguely heard it done by very experienced canopy pilots but I don't know much about it.

7. B-line stall.
Aerodynamically a variation of #1, but initiated by pulling down on the B-lines only. This isn't possible on most parachutes because the A and B lines cascade and both are controlled by the front risers. But it is possible on the old ParaFlite Evolution canopies, because they had separate A and B risers. Same can be done easily on paragliders. Wonder what it's like on a Xaos...
By pulling down on the B-line risers, the canopy deforms in a line along the B-lines. The wing becomes draggier and much less efficient, slows past the stall, descends steeply (not quite vertically) and quickly, but remains inflated.

[skydiverton 0]

Stalling your canopy is fun.
Also with a stiletto 107

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Using your droque to gain stability is a bad habit,
Especially when you are jumping a sport rig

[nael 0]

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Rear riser stalls happen more abruptly and with less warning, but they are a very docile stall. You can actually continue steering the canopy while stalled with rear risers.

I want to try stalling with rear risers this weekend. I just wanted to know before I did it if there's anything I should know before trying this. Obviously, I will talk to some instructors before I do it also. I read that it takes longer for the canopy to recover from rear riser stalls, as opposed to toggle stalls - is this true? Anything else I should know??

www.TerminalSports.com.auAustralia's largest skydive gear store