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pnuwin

PD Optimum Reserve - Opens softer. Is it slower?

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...So there is very little VERTICAL velocity at pack opening. That is how the 300 feet test can be passed.



I am shocked herein to learn that there is (apparently) no established drop-testing STANDARD. Am I alone now in being dismayed, if not maybe even maddened somewhat, that mfr's can CIRCUMVENT the 300' "rule" with such "trickery"? I personally find that actually, the more I am now typing and thinking of it, actually - REPREHENSIBLE.

I mean really, ...using the "throw" (and doing this seemingly INTENTIONALLY) of the airplane to SKEW (or at the very least obfuscate) the results so as only to say "they complied" - when "they" know very clearly and well, how it is otherwise considered by the jumpers who may RELY upon that equipment (and the "300 ft covenant") - on at least some level here now, just doesn't seem to set right with me. Am I alone in my thinking/now reaction to this?

If you are going to have testing, and performance covenants, and then testing so as to certify pieces of equipment to those specific certain performance covenants - one would have already assumed that at the very least, also TESTING STANDARDS would have been (and quite clearly) established too!

Wow Bill... you have now floored me, if this is so - and that mfr's are actually able to 'get away with this' ...and skew/obfuscate their "testing results", with this little tidbit.
coitus non circum - Moab Stone

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...So there is very little VERTICAL velocity at pack opening. That is how the 300 feet test can be passed.



I am shocked herein to learn that there is (apparently) no established drop-testing STANDARD. Am I alone now in being dismayed, if not maybe even maddened somewhat, that mfr's can CIRCUMVENT the 300' "rule" with such "trickery"? I personally find that actually, the more I am now typing and thinking of it, actually - REPREHENSIBLE.

I mean really, ...using the "throw" (and doing this seemingly INTENTIONALLY) of the airplane to SKEW (or at the very least obfuscate) the results so as only to say "they complied" - when "they" know very clearly and well, how it is otherwise considered by the jumpers who may RELY upon that equipment (and the "300 ft covenant") - on at least some level here now, just doesn't seem to set right with me. Am I alone in my thinking/now reaction to this?

If you are going to have testing, and performance covenants, and then testing so as to certify pieces of equipment to those specific certain performance covenants - one would have already assumed that at the very least, also TESTING STANDARDS would have been (and quite clearly) established too!

Wow Bill... you have now floored me, if this is so - and that mfr's are actually able to 'get away with this' ...and skew/obfuscate their "testing results", with this little tidbit.




That is why most manufactures will test to the 3 second requirement not the 300 feet. 3 seconds will always be 3 seconds but 300 feet can vary greatly depending on speed. Attached is the standard use in testing to TSO-C23d.

Sparky
My idea of a fair fight is clubbing baby seals

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...So there is very little VERTICAL velocity at pack opening. That is how the 300 feet test can be passed.



I am shocked herein to learn that there is (apparently) no established drop-testing STANDARD. Am I alone now in being dismayed, if not maybe even maddened somewhat, that mfr's can CIRCUMVENT the 300' "rule" with such "trickery"? I personally find that actually, the more I am now typing and thinking of it, actually - REPREHENSIBLE.

I mean really, ...using the "throw" (and doing this seemingly INTENTIONALLY) of the airplane to SKEW (or at the very least obfuscate) the results so as only to say "they complied" - when "they" know very clearly and well, how it is otherwise considered by the jumpers who may RELY upon that equipment (and the "300 ft covenant") - on at least some level here now, just doesn't seem to set right with me. Am I alone in my thinking/now reaction to this?

If you are going to have testing, and performance covenants, and then testing so as to certify pieces of equipment to those specific certain performance covenants - one would have already assumed that at the very least, also TESTING STANDARDS would have been (and quite clearly) established too!

Wow Bill... you have now floored me, if this is so - and that mfr's are actually able to 'get away with this' ...and skew/obfuscate their "testing results", with this little tidbit.




That is why most manufactures will test to the 3 second requirement not the 300 feet. 3 seconds will always be 3 seconds but 300 feet can vary greatly depending on speed. Attached is the standard use in testing to TSO-C23d.

Sparky

Sparky;

No one is "geting away with" anything. For the last 50 years, this is the way the "3 second test" has been done. It was written that way long before there was "modern freefall skydiving". This standard was decided on for emergency round parachutes used for escaping from airplanes in the distant past. We inherited this number. No one I know of remembers why 3 seconds was chosen in the first place.

I've been on every "TSO reform" committee, and I don't remember anyone proposing extending the "300 foot standard" to terminal freefall. We did write it in for cutaways, but never for terminal.

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Sparky;

No one is "geting away with" anything.



I didn’t say or even imply they were.

NAS 804 4.3.3, issued in 1949, is the first reference to “3 seconds” that I know of.


Sparky

NAS 804 is the first reference I can find also. One other thing to remember...TSO testing is done with new canopies, recently packed correctly by factory
riggers. It is not entirely reasonable to assume that a reserve packed by God knows who, by God knows which method, six months to a year ago, will open as quickly as a fresh factory pack. I have observed that a reserve packed the day of the drop test often opens noticeably faster than one packed even ONE DAY before.

When you add up all the "margins of error" in AAD firing altitudes, age and method of packing, body position, and pilot chute hesitations, giving up a single second of freefall, to gain an extra couple of hundred feet for your reserve to open, seems like a reasonable trade-off to me.

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When you add up all the "margins of error" in AAD firing altitudes, age and method of packing, body position, and pilot chute hesitations, giving up a single second of freefall, to gain an extra couple of hundred feet for your reserve to open, seems like a reasonable trade-off to me.



I think the current AAD activation altitudes are prety much spot on for the current types of skydiving and gear. Why? We're getting a lot of AAD activations, and a lot of saves. And next to no "it just snivelled into the ground"-cases after AAD activations.

If the AAD activation altitude were to moved up, all the other altitudes(break-off, main deployment, reserve decision altitude) would also have to be moved up at the same time. Otherwise we'd just be taking out some of the margin that keeps us from getting "two canopies out"-situations.

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If the AAD activation altitude were to moved up, all the other altitudes(break-off, main deployment, reserve decision altitude) would also have to be moved up at the same time.



Why would that be a bad thing?
"The ground does not care who you are. It will always be tougher than the human behind the controls."

~ CanuckInUSA

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Why should you get to decide how I skydive? Maybe you can't think of a good reason to open your parachute at 2000 feet but others of us can.



I merely asked why it would be a bad thing.

Bill has outlined a reasoned argument for why it would be a good thing. I just want to know why the other poster (or you for that matter) thinks it would be a bad thing. Let's have a reasoned debate. State your case, give evidence and then we'll all be wiser.

You haven't answered my question yet.
"The ground does not care who you are. It will always be tougher than the human behind the controls."

~ CanuckInUSA

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Why should you get to decide how I skydive? Maybe you can't think of a good reason to open your parachute at 2000 feet but others of us can.



I merely asked why it would be a bad thing.

Bill has outlined a reasoned argument for why it would be a good thing. I just want to know why the other poster (or you for that matter) thinks it would be a bad thing. Let's have a reasoned debate. State your case, give evidence and then we'll all be wiser.

You haven't answered my question yet.



Because that is treating the system not the cause. A skydiver who finds themselves at AAD altitude has already made some serious mistakes. Raising AAD altitude by a couple hundred feet will not change that fact but will create problems for others. If there is a need for equipment modifications you need look no farther than containers. A reserve pilot chute has a heavy steel spring in it. You compress it and then cover it with up to 6 flaps. It uses up a great deal of it's energy just pushing aside the flaps. What energy left has trouble launching the p/c far enough to clear the burble. That is just enough to add 1 to 2 hundred feet to deployment at terminal. All the flaps are driven by fashion not function. The manufactures try and deliver what the customer wants. Most jumpers what the rig to look good but haven’t got a clue what makes it work.

Sparky
My idea of a fair fight is clubbing baby seals

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