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jbrister

Student Rigs

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Hi all,

I have recently started skydiving (started on S/L and converted to AFF) and have some questions regarding student AFF rigs. My instructor has told me that;

1. The Cypres on the student AFF rigs used at our DZ are set to deploy a 230 at 750ft AGL. Does this sound a little low? The AAD's used on static line are set to 1200ft AGL.

2. It is not possible to stall a student canopy ( 260 Ram Air, not sure of the model). My experience of a recent hard-landing (flaired to early, to hard and to high, in NIL wind resulting in what felt like a stalled canopy) suggests different.

Also, on the subject of hard-landings, it was suggested to me that a two-stage flair might help with the problem of flairing early, but my instructors have advised against this. Can anyone suggest what I should do to overcome starting my flair to early?

Thanks,

J

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1. The cypres is set to go off at 750 - the only difference between a student cypres and an experianced cypres is that it will be activated by a much slower decent rate so that even if you have a partial mal it will fire your reserve where an experianced cypres wont.
it is low, but its high enough to save your life (ok you might want more time to sort stuff out but at least your reserve will be open).

2. It should not be possible to stall student canopies. The break lines will be lengthened to prevent this. I cannot comment on your recent landing, maybe you did stall it, maybe you didnt. I have seen a lot of students come down from high flares (some very high). The canopy will virtually stop forward movement and start to decend straight down. This may seem like a stall, but it isnt really. A true stall is where your canopy simply collapses in on its self and forms a ball of washing above your head... is this what happened?

Two stage flares work on ZP canopies, not F111. I would bet your on F111, old F111 at that. Stick to the one stage flare. Dont take anyones advice other than your instructors.

To flare, look out at a 45 deg angle, not straight down or you get ground rush and flare too high. Other than that you practice and plf when your wrong, you'll get it. you could try going up to a first floor building and looking out the window at a 45deg angle and memoriseing what thiings look like.

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1. From the Cypres user's manual

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It(the student Cypres) will activate the EOS when the rate of descent exceeds 29mph (13m/sec). The activation altitude is split. In the case of rate of descent being equal to that of freefall the opening altitude is at approx. 750 feet, being the same as with Expert CYPRES. However, should the rate of descent be lower than that of freefall but still above the limit of 29mph (e.g. with partially opened canopy), then Student CYPRES activates the EOS when the altitude decreases below 1000 feet above ground level. The student will then have some more
time to prepare for landing.



2. Students with very long arms may be able to stall a properly setup student canopy. The brake setting has to be a compromise between an effective flare when a short-armed student is using the canopy, and not stalling when a long-armed student is using it.

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2. It should not be possible to stall student canopies. The break lines will be lengthened to prevent this. I cannot comment on your recent landing, maybe you did stall it, maybe you didnt. I have seen a lot of students come down from high flares (some very high). The canopy will virtually stop forward movement and start to decend straight down. This may seem like a stall, but it isnt really. A true stall is where your canopy simply collapses in on its self and forms a ball of washing above your head... is this what happened?

Two stage flares work on ZP canopies, not F111. I would bet your on F111, old F111 at that. Stick to the one stage flare. Dont take anyones advice other than your instructors.



The rigs we are using are 7 months old, cost about £4K. I know the container is a Vector, but I can't say what the canopies are. When I flaired, the canopy stoped all forward movement and then surged forwards and downwards at (what felt like) considerable pace, and I hit the ground with a lot of forwards momentum. I was expecting to drop vertically, with possibly a slight rocking sensation (this is what we were taught would happen).

What could have caused this increase in forwards momentum? ( I didn't let the toggles back up, I simply held the flair and waited for the ground to come up).

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A true stall is where your canopy simply collapses in on its self and forms a ball of washing above your head


I thought a stall was where the wing looses lift, due to lack of airspeed and then surges forwards and down until enough airspeed is regained to create lift? (very crude description based upon my gliding experience)

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The way I was taught when to flare was:

Wait till you are scared then wait until you are really scared, then flare.

Imagine you are on the shoulders of somebody and when there feet are on the floor flare firmly with arms straight down (locked out). :)


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a stalled wing will surge forward.

yes a canopy is a wing, but only while it has forward movement - the fabirc is presurised into a wing shape by the air being rammed into the opeinings at the front - hence "ram air".

When you stall a canopy it ceases to have presurisation and the wing cross section will distort so that you can not expect normal wing like characteristics from its flying.

Sometimes it will crumple into a ball of washing, sometimes the ends will fold in on themselves, sometimes it will make a bow-tie shape. Sometimes it will even start to fly backwards a little way.

I have never heard of/seen a canopy stopping then surging forward when flared high. I do not have the experiance of many others on here though so look to them for an explanation of that - it may well be a true characteristic of a stalled canopy.

Perhaps an airlocked canopy will behave more like that as it is supposed to maintain its wing characteristics longer when subjected to depresurising effects. I doubt theres such a thing as a student canopy with airlocks though - they're mostly very small canopies.

What you describe is the clasic effects of letting toggles up. You say you didnt do this and I trust what you say on this so I'll eliminate that. I will say, however that when I was a student I had an odd sideways plant-landing that I swore was a cross wind... until I saw the video and myself let one toggle up. I would have staked anything on the fact that i'd flared properly, but the video never lies.

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Perhaps an airlocked canopy will behave more like that as it is supposed to maintain its wing characteristics longer when subjected to depresurising effects. I doubt theres such a thing as a student canopy with airlocks though - they're mostly very small canopies.


It was not an air-locked canopy. This was a big, docile student wing.

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What you describe is the clasic effects of letting toggles up. You say you didnt do this and I trust what you say on this so I'll eliminate that. I will say, however that when I was a student I had an odd sideways plant-landing that I swore was a cross wind... until I saw the video and myself let one toggle up. I would have staked anything on the fact that i'd flared properly, but the video never lies.


This was the firtst thing I suspected when I went through this in my head on the long walk back. I am certain that I held the flair. As soon as I realised what had happened, holding the flair was what I focussed on. In fact I was so busy thinking about holding the flair that I forgot to PLF, and paid with a sprained knee. (that's not to say I didn't let the toggles up, but in my mind I am certain I did not.)

I do remember that the weather was funny that day. We had NIL wind (1mph) most of the day with and the wind kept changing direction. The only thing I could think of was either a stall or a down-wind landing, but there wasn't really any wind.

I guess I just put this down to 'one-of-those-things' and practice, practice, practice flair-hold-plf!

I'm still a bit concerned about the Cypres settings though. I worked out that at terminal velocity, 750ft is 4 seconds away from a really bad day. (I guess I just make sure I never need it)

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Your reserve will open VERY quickly, that said you will have a canopy ride lasting maybe only 10 seconds or so. Thats enough to avoid a tree and flare.

Its there as a last chance... how often do you intend on using a last chance? Airbags still hurt like hell dont they. I know thats probably not much of a comfort but thats all there really is to say.

You're probably right, you probably held the flare... I cant explane it though, maybe someone else can help you with an idea. Perhaps it was a freak gust of wind, but thats less likely on a nil wind day.

Down wind landings feel mostly like into wind landings just with a lot more faster forward speed, but again theres not really a difference on nil wind days.

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> I doubt theres such a thing as a student canopy with airlocks though - they're mostly very small canopies.

Common misconception. The Lotus is made in large sizes (up to I think 190) and Brian can sometimes be talked into making custom size canopies.

>that's not to say I didn't let the toggles up, but in my mind I am certain I did not.

Get video on your next landing. I have video of someone that swore their canopy could'nt land them soft and they only pulled the brakes about halfway down and impacted with a lot of speed still. Another common mistake with early flarer's is they start the flare then let the toggles up an inch or two then pull down then let up then finish the flare. The bumping of the brakes usually results in poor landings.

Flareing is dynamic. There is never a "go to here and hold for 2 seconds then move hand to here" flare. Every landing is different. You need to fly the canopy all the way to the ground. Some times while only a foot off the ground you might need to give more input on one side to avoid a hole in the ground or something. Fly the canopy and that takes awareness of what you are doing all the way till you are on the ground and the canopy is under control.
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The way I was taught when to flare was:

Wait till you are scared then wait until you are really scared, then flare.

Quote



That would be @ 13,500ft then :P



Some of us might flair while still in the plane using that technique:P

Roy
They say I suffer from insanity.... But I actually enjoy it.

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