Deployment altitude regulations

[fasted3 0]

Deployment altitude is regulated for skydivers depending on the license held by the jumper. Altimeters with logging features record a deployment altitude, however, some would argue that they actually deployed higher than the recorded number. This discrepancy has been discussed on other threads, but I have not found an answer to this question: If the altimeter reports a lower altitude than the 'legal' altitude for a given license, is the jumper in violation of the regulations?

But what do I know?

[labrys 0]

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Deployment altitude is regulated for skydivers depending on the license held by the jumper. Altimeters with logging features record a deployment altitude, however, some would argue that they actually deployed higher than the recorded number. This discrepancy has been discussed on other threads, but I have not found an answer to this question: If the altimeter reports a lower altitude than the 'legal' altitude for a given license, is the jumper in violation of the regulations?

The USPA BSRs list container opening altitudes. Most electronic devices record canopy deployment altitude. Two different things.

Owned by Remi #?

[Jeff.Donohue 0]

Per the 2008 SIM, "Minimum container opening altitudes above the ground for skydivers are: (i) Tandem jumps--4,500 feet AGL; (ii) All students and A-license holders--3,000 feet AGL; (iii) B-license holders--2,500 feet AGL; and (iv) C- and D-license holders--2,000 feet AGL."

Your altimeter has no idea what your "container opening" altitude is. It is going to record as your "deployment altitude" the point at which your fall rate decreases below a specified threshold (my understanding is it varies from manufacturer to manufacturer, but I haven't looked into this).

Here's a simple example: you exit the aircraft, do an otherwise unremarkable skydive, throw your PC, your container opens (meeting the SIM requirement) but you have a bag lock. At that point, your altimeter will still be in free fall mode because your fall rate is still high.

Another example could be a long snivel (but depending on your altimater, body position, etc., the snivel might slow you down enough to show as "under canopy").

Conversely, I know other wingsuiters who can get their fall rate down to the point where their Neptune registers them as "under canopy" for most of free fall.

Having written all this, [insert the usual disclaimer about talking to an instructor here].

[damion75 0]

This may be a question of semantics. Certainly for the BPA it is not deployment altitude (moment of pull) which is regulated, but the opening altitude (when the canopy itself is opening) which is a wholly different thing...

From the BPA Ops Manual, Section 8:

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4 OPENING HEIGHTS

Minimum opening heights for main parachutes:-

4.1. Student Parachutists jumping round parachutes 2,000ft AGL

4.2. Student Parachutists jumping ram-air parachutes 3,000ft AGL

4.3. FAI ‘A’ Certificate (Red) parachutists and above 2,000ft AGL

4.4. Student Tandem Parachutists 5,000ft AGL

4.5. FAI `C’ Certificate (Red) holders, on displays 1,500ft AGL

So the canopy must be opening (often actually translated as the canopy must be open) by 2000ft for a licenced skydiver. The altitude recorded on the L&B altimeters as deployment altitude is (AFAIK) roughly equivalent to line stretch. If this recorded altitude was lower than 2000ft then in theory that jumper would have violated regulations...

The sensible thing to do is not get in that position in the first place - if you are getting a bollocking for being low, it is for your own safety and not to make the staff feel more important.

***************

Not one shred of evidence supports the theory that life is serious - look at the platypus.

[RB_Hammer 0]

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snip...
If the altimeter reports a lower altitude than the 'legal' altitude for a given license, is the jumper in violation of the regulations?

What are these 'regulations' you speak of? As far as I have been able to determine, there are no 'regulations', only the BSR's.
From the glossary:
BSR. Basic Safety Requirements. BSRs are USPA guidelines. They do not have force of law but are generally regarded as excellent minimum safety standards.

"I'm not lost. I don't know where I'm going, but there's no sense in being late."
Mathew Quigley

[fasted3 0]

What are these 'regulations' you speak of?

[pilotdave 0]

There's obviously no answer to your question. There's no rule written anywhere that says how the altitude can or cannot be measured. But using a device that consistently measures opening altitude lower than actual to determine if a BSR violation occurred is a bad idea. I'd guess that anyone doing that doesn't know that the device will give a significantly lower deployment altitude than where the jumper actually initiated deployment.

I tried to win that argument on a coach eval once... Evaluator said I pulled under 3,500 which is an automatic failure. I knew I pulled higher than that, but my only proof was a neptune that showed I pulled at 3,200 or something. Had I pulled under 3,500, it would have shown under 3,000... but that argument didn't work so well...

Dave

[riggerrob 558]

We can argue numbers all day, but the bottom line is that BSRs set "minimums."

Those minimums fell out of fashion a long time ago.
For example USPA's minimum opening altitude (i.e. show a pilot chute) of 2,000 feet for senior license holders was written back circa 1980 when the sport was transitioning from round to square canopies.

Fashion has moved on, setting higher standards (pun intended). Now freeflyers routinely toss their pilot chutes closer to 3,000 feet.
These days, if I am not "saddled out" by 2,500 feet, I mentally "kick" myself.

IOW If you have to argue about a hundred feet - close to USPA minimums - you sucked it waaaaaay too low.

[pilotdave 0]

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IOW If you have to argue about a hundred feet - close to USPA minimums - you sucked it waaaaaay too low.

I've been "legal" and seen 1200 feet on my neptune. It's not always a difference of just a few hundred feet.

Dave

[Orange1 0]

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[The USPA BSRs list container opening altitudes. Most electronic devices record canopy deployment altitude. Two different things.

Interestingly, in SA our BSRs do actually list deployment altitude: "Except on demonstration jumps every parachutist shall ensure that his main canopy is fully inflated not lower than 2200ft above ground level.

Out of interest, are there any other countries out there who do as well?

Skydiving: wasting fossil fuels just for fun.

[jacketsdb23 45]

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We can argue numbers all day, but the bottom line is that BSRs set "minimums."

Those minimums fell out of fashion a long time ago.
For example USPA's minimum opening altitude (i.e. show a pilot chute) of 2,000 feet for senior license holders was written back circa 1980 when the sport was transitioning from round to square canopies.

Fashion has moved on, setting higher standards (pun intended). Now freeflyers routinely toss their pilot chutes closer to 3,000 feet.
These days, if I am not "saddled out" by 2,500 feet, I mentally "kick" myself.

IOW If you have to argue about a hundred feet - close to USPA minimums - you sucked it waaaaaay too low.

I think what you said is important to note for all newer jumpers. I jump a crossfire 2 and pulled at 2200 on a recent "hop n' pop" load (I use that term loosely as I had reached terminal). When my canopy was finally opened my Neptune read 1150. I didn't violate a BSR. I did violate common sense. Todays canopies need to be opened higher for a lot of reasons:

1. Some are "eliptical" - line twists become malfunctions
2. They take longer to open (800ft or more is not uncommon)
2. We have a lot more to deal with after opening:

A) collapse slider, loosen chest strap, take off booties
B) Figure out where the rest of the 23 people on the load are
C) Fit yourself into a landing pattern (that begins immediately after opening - not at 1000ft.)
D) Avoid swooper lanes, or get yourself over to a swoop lane

[Feel free to add to the above list - these are just off the top of my head.]

Put it all together and the BSR requirement of a container opening by 2000ft for C & D license holders is no longer valid and paradoxically is no longer safe.



Marcel

Losers make excuses, Winners make it happen
God is Good
Beer is Great
Swoopers are crazy.

[labrys 0]

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Put it all together and the BSR requirement of a container opening by 2000ft for C & D license holders is no longer valid and paradoxically is no longer safe.

I don't think it's unsafe as a minimum. I think that the USPA is giving C and D license holders the opportunity to make their own choices. By that level someone should have the common sense to add altitude if they need to. Slow opening canopy... add altitude. Collapsable slider... add altitude.... on a large load.... add alti, etc.

The USPA also gives us no wind limits and that's "unsafe" too. But for now, it's still a matter of choice.

Owned by Remi #?

[jacketsdb23 45]

Fair point...and I don't think we have a habitual habit of pushing it to the limit. For the most part I see jumpers understanding the importance of opening higher.

Losers make excuses, Winners make it happen
God is Good
Beer is Great
Swoopers are crazy.

[LongWayToFall 0]

I feel your concern. I have been looking at my altimeter after jumps, and it shows a deployment about 400-500ft less than my pilot chute throw. For instance, on one jump I threw around 3200ft, container open maybe 3100, fully inflated at 2700ft. The deployment was registered at 2800ft.

[beatcreation 0]

I'm confused by this as well. I recently got spanked by a really fast opening canopy that i tossed at 5100 feet. My altitrack registered a deployment 1500 ft lower at 3600 ft when I know I was under a fully deployed canopy 400 ft after I tossed. I really don't get it.

[denete 2]

Yes, there is a difference between your mental recording of your dump altitude and the mechanical recording of your canopy being fully deployed.

You're still pretty much at terminal when you hit line stretch (at least in the eyes of your recording altimeter), unless you're jumping a BASE rig. So, you should consider almost all of your snivel to still be part of your freefall unless you've significantly slowed down and your altimeter passes a data recording point.

(old people should now begin to discount the statements above)

(insert typical disclaimers here)

- David

SCR #14809

"our attitude is the thing most capable of keeping us safe"
(look, grab, look, grab, peel, punch, punch, arch)

[beatcreation 0]

I completely understand that there is going to be a difference between what I know is deployed and what my altitrack will read but a 1000 ft plus discrepancy doesn't jive with me. I come from a highly technical background in areas close to aerodynamics and electromechanical devices such as a digital altimeter and this delta in read outs of measurement systems just drives me nutts. One of the posters earlier in this blog mentioned that they got spanked for their neptune reading 3200 ft which was below where they should have pulled. I would argue that if I were to come up with a good sampling plan and run an measurement system evaluation (mse) I would find that this form of measurement is not stable consistent or predictable.

[jsaxton 0]

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I don't think it's unsafe as a minimum. I think that the USPA is giving C and D license holders the opportunity to make their own choices. By that level someone should have the common sense to add altitude if they need to. Slow opening canopy... add altitude. Collapsable slider... add altitude.... on a large load.... add alti, etc.

EXACTLY!

The safe minimum pack opening altitude will depend on the type of jump.

[denete 2]

I wonder if the OP looked at the full data set or just the display data set. For the Neptune, there are so many records that aren't displayed on the LCD.

FWIW, I get about 650' difference between dump and the first canopy flight data point.

SCR #14809

"our attitude is the thing most capable of keeping us safe"
(look, grab, look, grab, peel, punch, punch, arch)

[popsjumper 2]

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FWIW, I get about 650' difference between dump and the first canopy flight data point.

At your fall-rate, that would be a hard opening...I mean, like 1 second.

(FWIW, that translates to 443 miles per hour.)

My reality and yours are quite different.
I think we're all Bozos on this bus.
Falcon5232, SCS8170, SCSA353, POPS9398, DS239

[pchapman 261]

Interesting to see the differences in terminology in different countries. Already mentioned were:

USA "pack opening altitude"

UK "opening" (with some variation in interpretation)

In Canada for the CSPA it is the minimum altitude at which the "parachute must be activated".

"Activated" could be interpreted different ways, whether it is first starting to pull the PC (only starting to activate it), or perhaps better, letting go of the PC.

[virgin-burner 1]

just to drop a question out of interest: usually i pitch about 3600ft, there is a DZ that requires licensed jumpers to pitch between 2300 and 2900ft. to be honest, that kinda intimidaded me. sometimes my sabre takes ages sniveling. like 1000ft or so. that could easily fuck up my harddeck.

when do you guys go for the PC!?

“Some may never live, but the crazy never die.”
-Hunter S. Thompson
"No. Try not. Do... or do not. There is no try."
-Yoda

[damion75 0]

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UK "opening" (with some variation in interpretation)

I'm not seeing a lot of variation in interpretation from the Ops Manual...

From the BPA Ops Manual, Section 8:

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4. OPENING HEIGHTS

Minimum opening heights for main parachutes:-

This clearly states main canopy opening. Not p/c throw, release or opening, and not container opening or linestretch. Just the altitude at which the main canopy must be opening.

Incidentally, I would be interested to know ballpark how much altitude a main canopy takes to 'open' from the moment it leaves the D Bag (obviously not therefore to include the altitude lost during pc toss and DBag deployment). Anyone? Bueller? Anyone?

***************

Not one shred of evidence supports the theory that life is serious - look at the platypus.

[kris2extreme 0]

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Incidentally, I would be interested to know ballpark how much altitude a main canopy takes to 'open' from the moment it leaves the D Bag (obviously not therefore to include the altitude lost during pc toss and DBag deployment). Anyone? Bueller? Anyone?

There is very little difference between setups in how long it takes the pilot chute to inflate, open the container, extend to linestretch, open the bag and remove the bag. The efficiency of the pilot chute and the length of the lines would be the only real variations in the sequence from pitch to bag removal, it takes about a quarter of a second to remove 2 feet from the stows, and if you are getting alot of hesitation from your pilot chute, then it needs to be replaced.

The canopy inflation is where the variation comes from. Some canopies like to fully inflate very quickly once they're introduced to the air (sabre, lightning, etc).. Other canopies like the velocity, katana, etc all have a little song and dance they like to do during the inflation sequence.

[Pulse 0]

Sure DZ's can regulate whatever, but they too need to inform their clients what their 'measure' is. If they are telling people their logging device is showing too low of an opening altitude that's what they should state. Forget about pack-opening, deployment, whatever. All they need to tell people is that their altimeters need to show at least 'such and such' altitude. You can't use the altimeter to judge the altitude USPA states you should have pack-opening by.

Also, some sense has to be involved here. USPA states that the decision to cutaway should be made by 1,800 feet and actions should be taken by 1,600 feet. Is this really acceptable with a minimum pack-opening of 2,000 feet? Then again. I've heard jumpers talk about being open at 1,500 feet and saying, "But I pulled at 3,500." As though that is acceptable. They should have been under their reserve by 2,000 feet in that instance.

It makes me wonder, when does it become a malfunction?

"Any language where the unassuming word fly signifies an annoying insect, a means of travel, and a critical part of a gentleman's apparel is clearly asking to be mangled."