Flying Divers (water)

[your_dreamguy]

Does anyone remember the rule for taking people who do dives?
I think it something like if they do not do compression dives, you must wait 8 hours and stay below 8000' cabin press alt. If they do a compression dive, you must wait 24 hours and stay below cabin pressure altitude of 8000.' However, I am not positive. Does anyone out there know the rule? Also, is it a rule-of-thumb or a law? Where do I find the info.

Look forward to you replies

 

[KnowledgeSeeker]

It's 12 hours before acending up to 8,000msl cabin pressure, for a dive not requiring a controlled acent. Then 24 hours for either a controlled acent dive OR after any dive where you are flying at cabin pressures exceeding 8,000 msl. I have never seen this as a reg. My understanding...it's a recommendation only. Yet it is a very important one to follow.

 

[Flymach2]

Hi...

It's in the AIM Chapter 8. By the way it's not Cabin Pressure, it's actual flight altitudes.

Regards

 

[Bluto]

Oh yeah? Well, you're ugly.

 

[Flymach2]

Yeah, well...I was born this way....what's your excuse?

How are they treating you over there? Ready to come back and do less for more money? Say "hi" to your better half for me.

 

[KnowledgeSeeker]

thanks for the correction mach2, been awhile since i looked at that reg (even though i dive).

 

[HAZ-MAT]

whats the waiting and altitude restrictions on muff diving?

 

[your_dreamguy]

Followup

Thanks for the posts. I was wondering how this rule came into effect. Is it because it takes the nitrogen that the diver was breathing, 12 and 24 hours to exit the body of the diver? Will flying at higher altitudes cause further expanision of nitrogen in the diver's system if this rule is not followed? Did this rule go into effect because one day someone took up a diver and noticed that the diver got into severe pain?
Look forward to you replies.

 

[jergar999]

It could be that the nitrogen in the bloodstream compresses during the dive, and could take up to that long to decompress, or it could be a secret FAA anti-diving conspiracy.

 

[RockyMnt1]

Flying Divers

My advice is to wait at least 24 hours after the last dive before transporting divers anywhere no matter what the dive profile was. There are just too many factors that the pilot cannot verify affecting the nitrogen release issue:

1) Which decompression tables were used? The orginal US Navy tables assumed that a certain % of folks would get the bends. They had a decompression chamber on board, so no big deal. Not so with sport divers. The later recreation dive tables are supposedly more conservative, but everyone is different so bends are still possible. Does the diver really know how to operate/read that dive computer? If the dive site was above 5000 ft msl, high altitude dive tables must be used. Were they used correctly?

2) Did the diver adhere to the ascent schedule? Maybe. Maybe not. You can't tell until the symptoms appear.

3) How much alcohol was consummed in the last 24 hours?? Divers are a pretty partying bunch (unlike pilots). Alcohol affects the release rate of the nitrogen.

4) Is/was the diver under any kind of stress before/during/after the dive? Stress also affects the nitrogen release rate. Did the diver eat/sleep enough?

5) How many repetative dives were accomplished before the flight?

I would hate to be in a pressureized cabin with a bunch of residual nitrogen time and have a cabin depressurization happen. Do you really want to take a chance and get entangled in such legal problems by taking a diver up too soon?

Just my thoughts..

 

[KnowledgeSeeker]

Yes, this came into effect because of peoples lack of understanding about how important this is. People have died and many people have been to the hospital because of it. Even though it is in the AIM it is still just a recommendation. Although most people who dive, myself included, wait 24hrs after a dive no matter what type of dive it is.

you asked if flying at higher altitudes will cause further expansion of the nitrogen in the divers body. Yes. Mabey this is a time to do a search on this subject. there is a lot of good info out there. Basically it does not matter whether they are a diver or not. All pilots/divers experience the acumulation of nitrogen in the blood when going to lower pressures and the subsequent off-gasing of the nitrogen. How severe it is depends on a lot of factors. Try HERE for a case history of someone getting the bends in Australia from only flying and not diving. Generally speaking, though, the highly compressed air that is breathed by making a scuba dive is when things get ugly.

 

[cj610]

Took a vacation out to Maui and rented a C-172 along w. CFI who also happened to be a dive master. He was telling me that divers should actualy wait 48 hours before flying. I don't think many people would heed that advice. Neither would the dive boats want to advertise that. When on vacation you have to pack in as much action as possible in the few days you have available.

CJ610

 

[Typhoon1244]

whats the waiting and altitude restrictions on muff diving?

Muff diving is not permitted by the FAR's at any altitude. That would make flying too fun!