High Speed Stall

[JayhawkJumper 0]

I saw this being mentioned in an earlier thread about a crash. Could someone explain exactly what a high speed stall is?

[skygod7777 0]

it means you stall at a high speed

basically, what their talking about is if you hook, and then grab your rears, and pull to far down, you'll stall the canopy, even if your going really fast.

someone correct me if i'm wrong

later

[CanuckInUSA 0]

Pilots are taught that they can stall a wing at any airspeed and at any attitude. So a high speed stall can occur when the pilot (includes canopy pilots) abruptly changes the wing's attitude and thus disrupts the flow of air over the wing (or canopy).

I don't believe I have any experience with high speed canopy stalls, but I am told that they can be hard to detect due to the added speed. But the canopy is falling instead of flying and low to the ground this can not be good karma.

Try not to worry about the things you have no control over

[quade 4]

Read http://futurecam.com/stalls.html.

quade -
The World's Most Boring Skydiver

[SkydiveMonkey 0]

Clicky link

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[rigging65 0]

A stall is when you reduce the airflow over the lifting portion of the wing to the point that sufficient lift cannot be produced to keep the wing aloft.

This can happen at any air speed, because if you abruptly take the leading edge out of the airflow (by drastically changing the angle on the wing) you no longer have sufficient air flow to produce enough lift to keep the wing aloft.

This is like as hauling in rear risers hard and fast. It takes the leading edge out of the airflow and you stall, regardless of speed.

A slow speed stall (or what most people think of as a "stall") is when you slow the flight of the wing to the point that not enough air is flowing over the wing to maintain sufficient lift...it's the same failing, just a different way of getting there.

"...and once you had tasted flight, you will walk the earth with your eyes turned skyward.
For there you have been, and there you long to return..."

[diablopilot 2]

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A slow speed stall (or what most people think of as a "stall") is when you slow the flight of the wing to the point that not enough air is flowing over the wing to maintain sufficient lift...it's the same failing, just a different way of getting there

Of course an added effect/result for the slow speed stall is the phenomena jumpers come to associate with a "stall". When the airspeed approaches, and then passes 0mph forward speed (ie flying backwards) the canopy looses pressure and tends to fold up. This will eventually happen in a high speed stall, however not necessarily at the onset. Recognizing the onset of a high speed stall can be an a** saving skill to pilots of all skill levels.

I'm sure you know this, just pointing it out for those that may not.

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[rigging65 0]

Quote

When the airspeed approaches, and then passes 0mph forward speed (ie flying backwards) the canopy looses pressure and tends to fold up.

Yeah, but the canopy doesn't have to be flying backwards before it looses structure/lift. Simply slowing the canopy down enough (not all the way to zero, in this hypothesis) reduces incoming air pressure to the cells to the point that overpressure and material load (ie- the lines causing the now less inflated canopy to deform) pushes the air inside the cells out of the nose and the canopy collapses... Which of course means that you no longer have any lift going on. In fact, you would begin to lose effective lift even as the wing begins to deform, because you'd be destroying the airfoil shape.

IMO, the resulting shape of the collapsing canopy causes it to glide slightly backwards. What I'm saying is that it's not the flying backwards that collapses the canopy, it's the collapsing that causes it to fly backwards, that's all.

"...and once you had tasted flight, you will walk the earth with your eyes turned skyward.
For there you have been, and there you long to return..."

[diablopilot 2]

Agreed.

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

[bobsled92 0]

There's alot of wild things that I'll pass up trying.
Even the experts/pros fall victim to bad timming
I'm looking forward to taking a canopy flight class
from Chuck Blue (I need it).
This fellow does 1&2 awesome! but #3=timming-height+earth.
check out www.skydivemovies.com
under "public" and file is barrelroll3.

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http://www.hangout.no/speednews/

[Steel 0]

Hi speed stalls can be oh so exciting. (more to watch than to perform ofcourse) Anyway you definately do NOT need rear risers to do them. If your swooping skill is just slightly above the beginner level you just might be able to pull it off. First you need to go big, get your self surfing that turf as fast as you possibly can. Now to keep this as an injury and not fatality make sure make sure that you are no more than 2 feet off the ground when you perform the next step. Bury those toggles, bury them like you never buried them before. And most important make sure there is video of the event to post on the web. Now as you are cruising along the ground with a much higher ground speed than you want to loose total lift at and your canopy still manages to completely drop behind you, you will then know what it means to have a high speed stall.

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