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180 degree front riser requirement for "A"

 

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hackish  (No License)

Sep 18, 2007, 7:48 PM
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180 degree front riser requirement for "A" Can't Post

From another thread someone pointed out via PM that it's nearly impossible under a large canopy to successfully perform a 180 degree front riser turn.

I thought for sure that I had done it and satisfied the requirement for the CSPA "A". Upon further discussion it would appear that on a 1:1 wing-loading it should be nearly impossible for me to perform this task because of the G-forces involved.

So this weekend I'm going to grill the instructor for more details and try to re-do that portion of the requirements just to see if I am able to satisfy it.

This all begs the question of why the license would ask you to do a task that should be more or less physically impossible? Or are some people working on their "A" license flying smaller faster sport canopies? At my DZ the student gear is in the 280 range PD280/Parafab 284/Tutor 9 cell). At the DZ where I did my FJC they flew Mantas which were also around 280ish.

-Michael


Chris-Ottawa  (A License)

Sep 18, 2007, 7:54 PM
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Re: [hackish] 180 degree front riser requirement for "A" [In reply to] Can't Post

Hey Mike,

Not sure who told you it's impossible....but I did it. Now if I was asked to do more than a 360, yeah, it might get really tough.

Imagine me, 5'8", 120 lbs, on the front riser of a Manta 288.

Trust me, it is fully possible.

In my opinion, if you "can't" do at least a 180...you're too weak to be jumping. That may sound harsh...but seriously.

Chris

Edited to add:
By "you're too weak to jump", I'm not indicating that this is you specifically, but jumpers in general.


(This post was edited by Chris-Ottawa on Sep 18, 2007, 7:57 PM)


Premier DSE  (D 29060)

Sep 18, 2007, 8:14 PM
Post #3 of 99 (3895 views)
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Re: [Chris-Ottawa] 180 degree front riser requirement for "A" [In reply to] Can't Post

I'm one of the ones that said it's very difficult to perform a front riser full 180 at his wingloading.
Hackish has indicated that his instructors (or someone) is requiring that he perform a full 180 degree turn via front risers in order to gain his A CoP. Front riser turns (Cat H) for an A license/CoP in the States may be waived in the event of insufficient strength (again demonstrating that it ain't so easy). I couldn't find any waiver, but that doesn't mean it can be waived, only that front/rear riser maneuvers are required. I'd find it very difficult to accept that a 180 on fronts is required of a student, depending on the wingloading. Then again, maybe it's different in Canada?


monkycndo  (D License)

Sep 18, 2007, 8:16 PM
Post #4 of 99 (3894 views)
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Re: [hackish] 180 degree front riser requirement for "A" [In reply to] Can't Post

If you want to make the front riser pressure lighter, hit the brakes first. As soon as you let off the brakes, pull down one riser. It will be much easier. As taught by Brian Germain.


bob.dino  (E 2185)

Sep 18, 2007, 8:36 PM
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Re: [monkycndo] 180 degree front riser requirement for "A" [In reply to] Can't Post

In reply to:
If you want to make the front riser pressure lighter, hit the brakes first. As soon as you let off the brakes, pull down one riser. It will be much easier.

This is the answer. Go to half brakes and hold for 5+sec. Smoothly let up the toggles and pull down the front riser. Easy!


loumeinhart  (D 30065)

Sep 18, 2007, 8:39 PM
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Re: [monkycndo] 180 degree front riser requirement for "A" [In reply to] Can't Post

In reply to:
hit the brakes first. As soon as you let off the brakes, pull down one riser

I also use this as a final traffic check before riser input, I almost fly my entire base leg in deep brakes (with regard to traffic).


kelpdiver  (B 7)

Sep 18, 2007, 8:39 PM
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Re: [monkycndo] 180 degree front riser requirement for "A" [In reply to] Can't Post

In reply to:
If you want to make the front riser pressure lighter, hit the brakes first. As soon as you let off the brakes, pull down one riser. It will be much easier. As taught by Brian Germain.

but begs the question, what was the point then?


bob.dino  (E 2185)

Sep 18, 2007, 8:49 PM
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Re: [kelpdiver] 180 degree front riser requirement for "A" [In reply to] Can't Post

In reply to:
In reply to:
If you want to make the front riser pressure lighter, hit the brakes first. As soon as you let off the brakes, pull down one riser. It will be much easier. As taught by Brian Germain.

but begs the question, what was the point then?

So the jumper can see & feel how a canopy reacts to front riser input?


Many swoopers start from brakes.


hackish  (No License)

Sep 18, 2007, 9:06 PM
Post #9 of 99 (3853 views)
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Re: [monkycndo] 180 degree front riser requirement for "A" [In reply to] Can't Post

Spent the drive home considering a post I read about the force vectors of landing and flare some of it commented on by Brian Germain. Just trying to work out the physics of what happens and if it's possible on the gear a student would fly...

Turns out I'm wrong on the CSPA requirements as they ask for:
Under canopy, demonstrated a 360 front riser spiral (above 2000 ft)

So in pondering things I've got a bit of an incomplete picture of what happens when you pull down on a front riser. I assume on a 9 cell configuration the front riser is attached to the A and B lines of 4 1/2 of the cells?

In full glide I assume they're going to be supporting about 1/4 of your weight which you need the strength to "lift". So if you pull down on the front riser you're not only going to change the angle of attack for one side of the canopy but your weight may pivot toward the front riser you're pulling increasing the angle of attack on the other side because the opposite force is applied to the C&D lines on that side...

I think this is going to be a more consistent or "aggressive" change on a more elliptical canopy and more abrupt on one with a different aspect ratio (smaller from front to back). I assume this is why the sport canopies respond faster. Gets complicated really fast. I'm assuming here that an elliptical canopy is shaped such that the length of the lines are equal rather than something that flies "flat" above your head. If the canopy is tapered it should even be more aggressive as the AOA should change more toward the outsides...

So that covers how I understand the canopy will then begin the spiral turn but as the turn goes there will be centrifugal force applied from your mass to the lines plus the riser you're holding down. This may as DSE pointed out via PM overcome your strength. I wonder if the force isn't applied more to the unpulled toggles as in theory the changed angle of attack should mean less lift on the corner of the canopy you're pulling the riser on?

If you put on the brakes as monkycndo says then your inertia should swing you forward a bit causing more slack in the front risers and thus making it easier to pull down but will that make you do the front spiral better? I'm not convinced because I assume the spiral comes from the deformation of the wing - something not yet accomplished by taking up the slack of swinging your mass forward from applying brakes.

Ok I worked a 16h shift and now my head hurts... Anyone have comments on the physics here?

-Michael


murps2000  (D 23114)

Sep 18, 2007, 9:36 PM
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Re: [hackish] 180 degree front riser requirement for "A" [In reply to] Can't Post

Check out Brian Germain's book "The Parachute and it's Pilot". It will answer many of your questions. Among other things, he discusses in depth the effects of various control inputs on the CG and angle of attack of your canopy.


Premier billvon  (D 16479)
Moderator
Sep 18, 2007, 10:04 PM
Post #11 of 99 (3819 views)
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Re: [hackish] 180 degree front riser requirement for "A" [In reply to] Can't Post

>If you put on the brakes as monkycndo says then your inertia
>should swing you forward a bit causing more slack in the front risers and
>thus making it easier to pull down but will that make you do the front
>spiral better?

It makes the turn easier to initiate by putting the canopy in its "recovery" regime; that unloads the lines momentarily. The forces will still increase as the spiral steepens.


dragon2  (D 101989)

Sep 19, 2007, 1:00 AM
Post #12 of 99 (3772 views)
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Re: [hackish] 180 degree front riser requirement for "A" [In reply to] Can't Post

Quit whining Wink over here we need to do 3x360 one way followed by 3x 360 the other way on frontrisers for B Crazy

Luckily I was exempt because of all my crw jumps, but man Crazy


speedy

Sep 19, 2007, 2:02 AM
Post #13 of 99 (3765 views)
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Re: [dragon2] 180 degree front riser requirement for "A" [In reply to] Can't Post

In reply to:
Quit whining Wink over here we need to do 3x360 one way followed by 3x 360 the other way on frontrisers for B Crazy

Luckily I was exempt because of all my crw jumps, but man Crazy

That is no problem with a R.A.G.E from Paratec.
You can steer that thing with front risers all the time. There is very little pressure on the fronts, which makes for a lot more pressure on the rears.


phoenixlpr  (D 3049)

Sep 19, 2007, 2:43 AM
Post #14 of 99 (3752 views)
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Re: [speedy] 180 degree front riser requirement for "A" [In reply to] Can't Post

In reply to:
That is no problem with a R.A.G.E from Paratec.
You can steer that thing with front risers all the time. There is very little pressure on the fronts, which makes for a lot more pressure on the rears.
AKAIK R.A.G.E. is not a student canopy... Wink

I've heard that you even have to use fronts to inflate your canopy. So they should be universal...Pirate


kallend  (D 23151)

Sep 19, 2007, 7:13 AM
Post #15 of 99 (3667 views)
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Re: [dragon2] 180 degree front riser requirement for "A" [In reply to] Can't Post

In reply to:
Quit whining Wink over here we need to do 3x360 one way followed by 3x 360 the other way on frontrisers for B Crazy

Luckily I was exempt because of all my crw jumps, but man Crazy

And the purpose of that demonstration is...?


rehmwa  (D 12816)

Sep 19, 2007, 7:23 AM
Post #16 of 99 (3654 views)
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Re: [loumeinhart] 180 degree front riser requirement for "A" [In reply to] Can't Post

In reply to:
I almost fly my entire base leg in deep brakes (with regard to traffic).

I'd like to thank everyone that does this, especially when it's crowded. AND especially when you are one of the first down. It's just great to see the pattern get all crushed and crowded and dangerous above you all.


illusioneer  (A 13037)

Sep 19, 2007, 7:29 AM
Post #17 of 99 (3646 views)
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Re: [hackish] 180 degree front riser requirement for "A" [In reply to] Can't Post

On a navigator 280 I have tried a few front riser turns...the canopy did not respond much at all...I would have a hard time doing any front riser turns.


atsaubrey  (A 44961)

Sep 19, 2007, 7:50 AM
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Post deleted by atsaubrey [In reply to]

 


kallend  (D 23151)

Sep 19, 2007, 8:26 AM
Post #19 of 99 (3607 views)
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Re: [atsaubrey] 180 degree front riser requirement for "A" [In reply to] Can't Post

In reply to:
In reply to:
Hey Mike,

Not sure who told you it's impossible....but I did it. Now if I was asked to do more than a 360, yeah, it might get really tough.

Imagine me, 5'8", 120 lbs, on the front riser of a Manta 288.

Trust me, it is fully possible.

In my opinion, if you "can't" do at least a 180...you're too weak to be jumping. That may sound harsh...but seriously.

Chris

Edited to add:
By "you're too weak to jump", I'm not indicating that this is you specifically, but jumpers in general.

I am a pretty big boy and can bench more than my weight which is over 300lbs. I CANNOT pull down my front risers so I guess I should quit jumping. When I can see a tandem master do front rider turns then I will quit jumping. Tell you what you come jump my rig and I will consider it if you can pull a front 180 on my rig.

Forget the bench presses, do more pull-ups.Wink


rehmwa  (D 12816)

Sep 19, 2007, 8:57 AM
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Re: [atsaubrey] 180 degree front riser requirement for "A" [In reply to] Can't Post

In reply to:
When I can see a tandem master do front rider turns then I will quit jumping.

I think most people can do a single pull up and hold their own weight.

I doubt many can pullup twice their weight.


atsaubrey  (A 44961)

Sep 19, 2007, 9:07 AM
Post #21 of 99 (3576 views)
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Re: [rehmwa] 180 degree front riser requirement for "A" [In reply to] Can't Post

Sorry certain things get under my skin, and I hadn'e had my cup of coffee this morning. Thought it is better to delete than start a bitch. sorry for my attitude.


Premier billvon  (D 16479)
Moderator
Sep 19, 2007, 9:07 AM
Post #22 of 99 (3576 views)
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Re: [kallend] 180 degree front riser requirement for "A" [In reply to] Can't Post

>Forget the bench presses, do more pull-ups.

Yep. To pull a riser down you need the other set of muscles in your arms. But if you can do a pullup you can pull down a riser.


atsaubrey  (A 44961)

Sep 19, 2007, 9:16 AM
Post #23 of 99 (3563 views)
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Re: [billvon] 180 degree front riser requirement for "A" [In reply to] Can't Post

I will admit I can do pullups (not many..lol), but can't get enough of a grip on a front riser to move it more than an inch or two. But thats me.


Premier billvon  (D 16479)
Moderator
Sep 19, 2007, 9:29 AM
Post #24 of 99 (3554 views)
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Re: [atsaubrey] 180 degree front riser requirement for "A" [In reply to] Can't Post

>but can't get enough of a grip on a front riser to move it more than
>an inch or two. But thats me.

Oh, OK! That's a different problem. One way to solve it is to grab the riser at the link where there's more "stuff" to hang onto. If you can't reach that, dive loops or dive blocks can help, and are fairly easy to add.


atsaubrey  (A 44961)

Sep 19, 2007, 10:15 AM
Post #25 of 99 (3526 views)
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Re: [billvon] 180 degree front riser requirement for "A" [In reply to] Can't Post

Not to take away from the original post, but no way I can reach the link. Heck my slider usually hangs out above the links about 4-5 inches and I can't reach it unless I grab a bunch of rear riser with one hand to be able to reach it. I will admit a 330 canopy is a mofo to move with front risers and I have yet to need to use them.


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