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adietkin

decision altitude

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Do you mean "decision altitude?" It's the altitude where I decide whether or not to cut away and use my reserve. It is different based on the type of dive I do, my vertical speed, the canopy I have, the rig I have, the reserve I have etc.

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If i'm in freefall with no parachute below 1800' I would go to my reserve, and then readily ground myself until I become smarter.

other then that decision altitude is where I decide to land the parachute I have or try another option. 1800' is my general number and i've stuck to that so far.
Losers make excuses, Winners make it happen
God is Good
Beer is Great
Swoopers are crazy.

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It's the lowest altitude that I will keep trying to fix a problem with my main (line twists, stuck toggle, that sort of thing). 2K in my case.
"There are NO situations which do not call for a French Maid outfit." Lucky McSwervy

"~ya don't GET old by being weak & stupid!" - Airtwardo

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2500ft decision altitude and to initiate main deployment no lower than 3800ft. Newbie jumper and these numbers were recommended to me by an very experienced instructor at my DZ.



Those numbers are fine, I'm not going to argue that, but if you find yourself in trouble at 2000 ft, or even 1500, you will be ok to chop. As far as 3800 for deployment altitude, that's a personal decision. You will have a hard time going on big ways pulling at that number. On the 15 way I jumped last weekend no one pulled over 3000. FYI, my comfortable deployment altitude is 3500 and my decision altitude is 1500.
Why would anyone jump out of a perfectly good airplane? Cause the door was open!

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FYI, my comfortable deployment altitude is 3500 and my decision altitude is 1500.



Rethink that decision altitude. The SIM recommends no lower than 1800 for D licensed jumpers.
"We've been looking for the enemy for some time now. We've finally found him. We're surrounded. That simplifies things." CP

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1500' too low? Yes and no in my opinion.

To some degree, "decision altitude is where ever you are at."

If you are high, you don't have to delay a decision down to that altitude, for it is the minimum altitude you prefer to chop.

And if you are low, you may choose to move the limit down, as a practical decision even if it isn't ideal.


So if you are on a jump where you pulled expecting to be open at around 3000' and you have an issue, you might not screw around with high speed problem below 2500', yet screw around with a lower speed problem no lower than your "normal" decision altitude of 1800'.

But if you pulled at 2200' you may be snivelling through 1800' so you certainly don't use 1800' as your decision altitude. You might use 1500' as the limit.

And if you really pulled low, and were snivelling through 1500', what then? It may not be ideal, but I think a lot of people would stick with their main if the opening sequence seemed to be progressing normally, instead of chopping in mid-snivel.

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FYI, my comfortable deployment altitude is 3500 and my decision altitude is 1500.



Rethink that decision altitude. The SIM recommends no lower than 1800 for D licensed jumpers.



If I have an issue I'm definitely going to chop higher, not going to screw with it until 1500, but if I find myself at 1500 with a canopy I cannot land, I'm chopping it.
Why would anyone jump out of a perfectly good airplane? Cause the door was open!

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I just had my 4th cutaway this week. Taking a canopy course, so I opened a little higher than normal for traffic separation. VERY hard opening that resulted in significant damage to the two outboard cells of the canopy. I was able to stop the spin with full left toggle and fly it generally toward the landing area. The canopy was flapping and folded over itself on the right side. Clearly not landable; barely controllable and definitely not "square." Since it was clear that I would have to cut away, I cut away at 3000 to give myself maximum time to handle any issues that might arise under the reserve.

In my view, decision altitude is the altitude you know you must cut-away after deciding that the main is not controllable or landable. Making that assessment higher rather than lower affords you more time to deal with any reserve issues you might encounter. The SIM says 1800 minimum for a D license holder. I'd prefer not to wait until 1800 if I know I am going to have to cut away, but with a skyhook, I would not hesitate to cut away at 1500 if I opened low and realized I had a problem with the main at that altitude. But that is getting down to the bottom end, I think, and I have a skyhook, which is a plus in such a situation.
Charlie Gittins, 540-327-2208
AFF-I, Sigma TI, IAD-I
MEI, CFI-I, Senior Rigger
Former DZO, Blue Ridge Skydiving Adventures

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FYI, my comfortable deployment altitude is 3500 and my decision altitude is 1500.



Rethink that decision altitude. The SIM recommends no lower than 1800 for D licensed jumpers.



If I have an issue I'm definitely going to chop higher, not going to screw with it until 1500, but if I find myself at 1500 with a canopy I cannot land, I'm chopping it.



I think maybe people are talking past each other because they're using 2 different definitions for "decision altitude."

One definition, which others in this thread have been using, and which I think is the most commonly-used definition, is the lowest you are willing to try to clear a partial malfunction before stopping further attempts and cutting away.

However, you seem to be referring to the lowest you are willing to handle a partial malfunction by cutting away first, rather than going straight to your reserve without cutting away first.

For most people, the threshold altitude for the first scenario would probably be higher than that for the second one.

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