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How much does altitude affects your deep break settings and why? How much higher do you have to go from the reference altitude at which you set the DBS for it to make a significant difference?

please correct me if im wrong, but i think it would be negligible. the only exception MIGHT be if you lived in colorado for example, and set your breaks with bare minimum forward speed, then went down and jumped an object in san diego, i would think that maybe you could stall on opening but in that case your brakes are probably set borderline too deep in the first place.

please chime and and flame me if i sound like an idiot, i know you will.
=)

Based on my experience it matters a little bit, but as
you point out it must depend on large differences.

Twin Falls is 4200 feet MSL and North FL is ~200' MSL
plus temperatures can range from 32 to 102 Fahrenheit
or 0 to 39 Celsius here in the panhandle, so there is a
small difference that can be seen comparing videos
from Perrine versus Wanda with same rig and guy.

Anyone who has hauled meat all day long can attest
winter days are easier than summer for landings.

Was digging through my ACE manual and it stated to be careful with DBS when opening at higher altitudes or jumped by lighter jumpers because it could stall. So I was wondering how much higher would it need to be to make a difference? Is the stall at higher altitudes caused by the parachute pressurizing slower (less dense air) than at sea level (denser air)? Is temperature then similar too i.e. DBS at -26 F could stall in Arizona at >100 F?

As Altitude goes up, air gets thinner.
As Altitude goes down, air gets denser.

As Temperature goes up, air gets thinner.
As Temperature goes down, air gets denser.

As Humidity goes up, the air gets thinner.
As Humidity goes down, the air gets denser.

If you like math and graphs, here is a link:
http://en.wikipedia.org/...sity_of_air#Altitude

I think exit weight would make a bigger difference than temperature or altitude, but it would be pretty tough for any of those factors to make you stall in factory DBS because they're set pretty conservatively (i.e. shallow). I think these factors would only be significant with finely tuned custom DBS.

I think your right as mojos ages ago came with only one break setting they wanted u to jump from a plane find stall points and mark and make your own dbs settings the newer ones they asked for your weight to make dbs..... i have thrown a base rig pca off an object with 20kgs of weight in the harness on shallow brake setting and the canopy opened but backsurged into the object as it was opening so i think weight is a big factor

20 Kilograms = 44 Pounds (x)
72.5 Kilograms = 160 Pounds (Y)

Brett, changing the payload that much is
really a gigantic change! X / Y = 27.5%

Tandem-BASE is the only time a pilot would
experience changes in payload of that extreme.

This would be like Chuma taking a football
player followed by a hot little cheerleader

Lol i know its a big change.....i was just saying...but a heavy person vs a light person should have different dbs settings jumping the same size canopy thats all i was trying to imply
And yes i did get bored enough to throw a base rig off something with a weight on it.....haha try climbing a tower with 20kgs in bag it sucks so much

The factory "deeper" settings on your Ace should be fine at any altitude.

In my experience customizing deep brakes, Atair and Consolidated Rigging are the most conservative (i.e. have the shallowest brakes) in their factory settings. Aside from some early generation OSP's, every canopy I've seen from these manufacturers has opened without stall/sink at any elevation.

I've heard rumors that some Trango 3's might have deeper brakes from the factory, but have not tested one myself.

Apex's settings are deeper than CR or Atairs, but still I have yet to see an Apex "deeper" factory setting I wouldn't be comfortable using at any elevation in zero wind.

The factory settings on Bad Seed Mayhem canopies (I mention this because I know you own one) are the deepest I've encountered. In several cases I've had to lighten the factory settings when customizing brake settings on a Mayhem because the deepest factory setting was causing the canopy to stall at deployment in zero wind.

In my personal experience, my troll mdv deep break settings were too deep from the factory. After opening in a stall a couple times, I never used them again. Never had issues with the factory settings of any other canopy I jumped or owned.

What's the DOM on that Troll?

Probably 2006??? Don't remember for sure, I feel like maybe that was a recurring issue then, but not like it's a big deal... Just wanted to bring it up. :)

which is weird, i have a 2013 OSP, and i literally had to take a total of 4 inches off the lines. i took 5 off over the course of several jumps, and was stalling out at perrine with a very mild tailwind, so after all it was something like 4 or 4.5 inches total. very very conservative brake lines out of the factory.