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Your "Usual" Jump Altitude?

 


FlyingRhenquest  (B 37920)

Jan 9, 2013, 7:36 AM
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Your "Usual" Jump Altitude? Can't Post

Hey All! I'm re-reading the USPA SIM in preparation for the B license exam, and noticed the section on altitude. You know, the bits on oxygen over 15000 MSL and how that's an "Intermediate Level" jump. I was a bit surprised, because pretty much every jump I've ever done has been between 17 and 18K MSL (around 12K AGL) and I've never seen anyone go for the oxygen, so I never thought that altitude was that big a deal. I also remember from hang gliding days my instructor mentioning that you don't want to go above 18K without bringing your own oxygen, so that was the number that was sticking in my head.

I don't think I'd want to hang out at that altitude for long or go much above it, but it seems pretty comfortable for the length of time that I'm there.

Funnily enough I can get higher in my car than the recommended altitude to start the onboard oxygen for intermediate and high altitude jumps. Maybe I should start watching my passengers for signs of hypoxia! Though sometimes they're not apparent until the passenger gets out of the car at 12100 feet and falls down...

Anywhoo, what altitude do the folks at lower elevations usually jump from? Does your dropzone offer rides to 15K or higher?


wolfriverjoe  (A 50013)

Jan 9, 2013, 3:16 PM
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Re: [FlyingRhenquest] Your "Usual" Jump Altitude? [In reply to] Can't Post

Home DZ, Ground level 800 MSL. Jumps out of the 182 at 10000 - 11000 AGL.

SDC Ground level 900 (IIRC), Jumps out of Otter or Skyvan approx 14000 AGL.


wasatchrider

Jan 9, 2013, 3:39 PM
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Re: [wolfriverjoe] Your "Usual" Jump Altitude? [In reply to] Can't Post

we are at 4,000 or 4,500 ft elevation maybe and fly to 13,500 agl


Bluhdow  (B 37052)

Jan 9, 2013, 4:35 PM
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Re: [FlyingRhenquest] Your "Usual" Jump Altitude? [In reply to] Can't Post

Perris and Elsinore are both around 1500 feet I believe.

Our jumps are 12,500 AGL which makes it 14,000 MSL.

Sounds like we should be able to take it higher! What would keep a DZ from bringing people up higher? Fuel costs? Keeping the loads turning faster?


wolfriverjoe  (A 50013)

Jan 9, 2013, 6:11 PM
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Re: [Bluhdow] Your "Usual" Jump Altitude? [In reply to] Can't Post

In reply to:
Perris and Elsinore are both around 1500 feet I believe.

Our jumps are 12,500 AGL which makes it 14,000 MSL.

Sounds like we should be able to take it higher! What would keep a DZ from bringing people up higher? Fuel costs? Keeping the loads turning faster?

FAR 91.211

Oxygen is required for crew if the place goes over 14k MSL.
I could be wrong about SDC going to 14k AGL.


FlyingRhenquest  (B 37920)

Jan 9, 2013, 7:29 PM
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Re: [wolfriverjoe] Your "Usual" Jump Altitude? [In reply to] Can't Post

Hmm, I never see the pilot way from way back by the door (and looking the other direction) like I usually am.

The wording in the SIM seems vague to me, up to 20K feet. There's definitely an oxygen system, and I vaguely recall someone mentioning that if you asked for it they'd give it to you. I've just never seen anyone ask for it.


Southern_Man  (C License)

Jan 9, 2013, 8:18 PM
Post #7 of 18 (1840 views)
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Re: [FlyingRhenquest] Your "Usual" Jump Altitude? [In reply to] Can't Post

the Far 91.211 is not ambiguous about supplemental oxygen:



Supplemental oxygen.

(a) General. No person may operate a civil aircraft of U.S. registry--
(1) At cabin pressure altitudes above 12,500 feet (MSL) up to and including 14,000 feet (MSL) unless the required minimum flight crew is provided with and uses supplemental oxygen for that part of the flight at those altitudes that is of more than 30 minutes duration;
(2) At cabin pressure altitudes above 14,000 feet (MSL) unless the required minimum flight crew is provided with and uses supplemental oxygen during the entire flight time at those altitudes; and
(3) At cabin pressure altitudes above 15,000 feet (MSL) unless each occupant of the aircraft is provided with supplemental oxygen.


wasatchrider

Jan 9, 2013, 8:21 PM
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Re: [Southern_Man] Your "Usual" Jump Altitude? [In reply to] Can't Post

its amazing how many rules of the Far you guys talk about get broken


pchapman  (D 1014)

Jan 9, 2013, 8:46 PM
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Re: [Southern_Man] Your "Usual" Jump Altitude? [In reply to] Can't Post

Note the distinction that the crew must be provided with and use oxygen, while the passengers must only be provided with oxygen.


MikeJD  (D 10605)

Jan 10, 2013, 3:34 AM
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Re: [FlyingRhenquest] Your "Usual" Jump Altitude? [In reply to] Can't Post

I guess rules are always going to involve some generalisation or you wouldn't be able to administer them - and they'll generally err on the side of caution.

Obviously each person's oxygen requirements will be slightly different, and especially for people local to your DZ if they're already acclimatised through living at a higher altitude. I'd have thought that a visiting jumper from a lower-lying area might feel the effects of 18K. Certainly it'd be at the back of my mind if I was going to that altitude, even though I've jumped many times from between 15 and 16K.


JohnMitchell  (D 6462)

Jan 10, 2013, 8:22 AM
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Re: [MikeJD] Your "Usual" Jump Altitude? [In reply to] Can't Post

In reply to:
I'd have thought that a visiting jumper from a lower-lying area might feel the effects of 18K. Certainly it'd be at the back of my mind if I was going to that altitude, even though I've jumped many times from between 15 and 16K.
I used to live at 4500 MSL, DZ at 5000' MSL. DC-3 chugging up to 10,500 or higher never bothered me. I moved down to sea level for a few years, came back to visit and almost had to crawl out the door on jump run. Damn. Laugh


Premier billvon  (D 16479)
Moderator
Jan 10, 2013, 8:41 AM
Post #12 of 18 (1588 views)
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Re: [FlyingRhenquest] Your "Usual" Jump Altitude? [In reply to] Can't Post

We play pretty fast and loose with O2 rules, and we usually get away with it because 1) we're not up there very long, 2) we descend quickly and 3) the place where the 18K jumps happen is generally places where the DZ is already at 5000 feet, so people are somewhat acclimated to higher altitudes already.

But it is a good thing to keep in mind, especially on the more difficult jumps (wingsuit and RW formations) where you'll be exerting yourself, in the door a long time, on jump run a long time or going to unusually high altitude. A personal O2 system can be a good idea, since it also allows bailout oxygen.


hchunter614  (B 30368)

Jan 10, 2013, 12:11 PM
Post #13 of 18 (1518 views)
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Re: [wasatchrider] Your "Usual" Jump Altitude? [In reply to] Can't Post

The key to point 1 is "for that part of the flight at those altitudes that is of more than 30 minutes duration". Unless you're in a very slow 182 it's unlikely that the pilot would be between 12.5k MSL and 14K MSL for 30 minutes.


chuteless  (D 41)

Jan 15, 2013, 7:28 AM
Post #14 of 18 (1251 views)
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Re: [FlyingRhenquest] Your "Usual" Jump Altitude? [In reply to] Can't Post

I have had quite a few jumps where I got ground rush at about 19000 ft. I have also had many when I got ground rush at 200 ft.

I guess my usual altitude was somewhere in between.

Bill Cole D-41 Canada


BigMikeH77  (B 39490)

Jan 15, 2013, 9:26 AM
Post #15 of 18 (1204 views)
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Re: [FlyingRhenquest] Your "Usual" Jump Altitude? [In reply to] Can't Post

It is really kind of bizarre now that you mention it... My first ever jump, a tandem, was outside Vegas where the elevation isn't nearly as high as it is here in Denver and I do believe that we jumped at 14,000 AGL. So using noob logic, i deduce that our friends in coastal areas theoretically OUGHT to be able to go all the way up to 17,000' above sea level without issue. BUT, remember, we are acclimated to the less dense air and rarely if ever tumble out of the car when we get to the summit of Loveland Pass. (I mean for real, man... My kids SKI from higher altitudes than that.)


DEG

Jan 15, 2013, 5:19 PM
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Re: [Southern_Man] Your "Usual" Jump Altitude? [In reply to] Can't Post

FAR's rule...period. If pilots allow breaking them, lots of questions arise, at the very least.


FlyingRhenquest  (B 37920)

Jan 15, 2013, 6:02 PM
Post #17 of 18 (1096 views)
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Re: [DEG] Your "Usual" Jump Altitude? [In reply to] Can't Post

Yup. I talked to the instructor administering the B license exam and he told me our DZ had an exemption from the FAA due do the starting altitude. Oxygen is available for anyone who needs it, but is not routinely used. Most of us are acclimated to higher altitudes, though as has been noted we do need to be aware of the warning signs and go on the oxygen if we need to. I don't know if this also pertains to the pilot, but I never sit close enough to him to see what he's doing.

I don't know what their process is for handling visitors from sea level. My family members were doing tandems, so their TIs were able to keep an eye on them. I think I'd want to be careful if I were a visiting fun jumper, especially on the first couple days at this altitude.

Likewise I suppose we should be prepared for oxygen procedures if we do jumps in the 15-20K range at other dropzones. Regulations and all! We might not actually need it, but it's not going to be harmful either.


diablopilot  (D License)

Jan 15, 2013, 8:23 PM
Post #18 of 18 (1075 views)
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Re: [hchunter614] Your "Usual" Jump Altitude? [In reply to] Can't Post

In reply to:
The key to point 1 is "for that part of the flight at those altitudes that is of more than 30 minutes duration". Unless you're in a very slow 182 it's unlikely that the pilot would be between 12.5k MSL and 14K MSL for 30 minutes.

there is a cumulative effect.....



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