Hypothetical: Deployment Stall

[imported_Tom Aiello]

I have been having a discussion with a friend on brake settings and deployment stalls. I have a hypothetical situation (ok, it's not really that hypothetical), and I wonder if anyone has any thoughts on they physics involved. Here goes:

A 200 pound jumper is using an Blackjack 280. The brakes are set perfectly to give him minimal forward speed on deployment.

In an effort to get chicks, he loses 15 pounds. Now, at 185 pounds, he finds that his formerly perfect brake settings are:

a) still perfect

b) too deep--his canopy stalls on deployment

c) too shallow--he has lots of forward speed on opening

d) there is some other effect

Obviously the PAC valves are going to add a bit of complexity. So, if you know the correct answer without the secondary inlets (i.e if the canopy was an Ace), please help me out with that.

I thought I knew the answer to this, but a review of wing aerodynamics is appearing to conflict with my personal experience.

Can someone help me?

Thanks,

--Tom Aiello
tbaiello@ucdavis.edu

[guest]

That's a good question. I'd like to know a little more about that myself. Common sense says that if he's already near his stall spead on deployment, underloading an additional 15 pounds would likely cause a stall on opening.

PAC valves??? I have no experience there.

Stay safe out there. hee hee hee --Dex

[554]

I believe that the answer is B, but I think it's a trick question. You either have to concentrate on BASE jumping or picking up chicks. Anyone that can do both should be praised and I need them to call me immediately. VERY hypothetical situation in my opinion.&-)

[guest]

Canopy stalls, but the valves assist in maintaining planform, preventing the collapse of the canopy, and assisting in recovery. Want to keep girlie? Reset DBS. Or discuss with adam. You know? the manufacturer.