Upper Control Line Configuration

[nicknitro71 0]

Modern Ram Air canopies have one of the following configurations as upper control lines (line 1 is the most outboard and consecutive numbers indicate 1/2 cell):

A: 1, 3, 4, 5 (total of 2 cells)
B: 1, 2, 3, 4 (total of 1 1/2 cells)
C: 1, 2, 3, 5 (total of 2 cells)
D: 1, 2, 4, 6 (total of 2 1/2 cells)
E: 1, 2, 3, 4, 5 (total of 2 cells)
F: 2, 3, 4, 5 (total of 2 cells)

Also see the poor pic

What do you think each configuration does in term of:

1. Opening
2. Toggle turn rate
3. Toggle pressure
4. Stall
5. Flare

Memento Audere Semper

903

[sid 1]

you're bored aren't you, Nick?

Pete Draper,

Just because my life plan is written on the back of a Hooter's Napkin, it's still a life plan.... right?

[nicknitro71 0]

To death!

Memento Audere Semper

903

[beezyshaw 0]

Quote

What do you think each configuration does in term of:

1. Opening
2. Toggle turn rate
3. Toggle pressure
4. Stall
5. Flare

As someone who has been testing these configurations on canopies in development for many years, I can answer your question...

To put it in basic terms (but keep in mind that certain canopies respond in slightly different ways), the more towards the center of the canopy you place the UCL, the stronger the flair, the firmer the opening, and the heavier the toggle pressure and slightly slower turn rate (usually). On the contrary, the more toward the outboard cells you place the UCL then you get lighter toggle pressure, reduced flair power, and snappier toggle turns.

It is always a compromise of these issues when configuring the control lines on the trailing edge of the canopy. For instance, a canopy design that has an inherently strong flair can have the lines more outboard to give light toggle pressure without sacrificing good landings, etc., etc.

ps I just saw the part about the stall; the more outboard the control lines, the deeper the control stroke it takes to stall the canopy, and of course visa versa.

[darkwing 5]

I agree with Beezy. That is what I found out when building canopies in the late 1970's, and while modern elipticals, etc., change things a bit, I don't think they change things much.

-- Jeff
My Skydiving History