Another question about no-fly times

[Mustard Dave]

I personally like to wait at least 20-24hrs before I fly. The cabin in a plane is only pressurized to about ~8Kfeet and around 0.16 PO2.. they pressurize it just enough to keep you conscious to keep the stress low on the airframe. Cochran was the first to put a flight recorder in the dive computer as it was noticed a high correlation to flights after diving and DCS. I always have my Cochran in my carry on so in case I take a hit I have a log of of my exposure for analysis.

On my last flight my analox read 15.8% PO2 (not adjusted for humidity)... so they were pressurizing it just enough to keep everybody conscious.

Will the computer be monitoring the ambient pressure out of water? Neither of mine activate unless the contacts get wet.

 

[Scuba_Noob]

From your response, it sounds like you've already made your decision and are looking for confirmation.

But I'll echo everyone else and DAN's opinion. You shouldn't do the dive. You probably won't get DCS from a 15ft dive, but it's not worth the risk. It's just as easy to freedive to 15ft. Here's an article - http://www.diversalertnetwork.org/files/FADWkshpBook_web.pdf

DAN recommends 12hr minimum, pretty arbitrary; 18 hours for multiple days of diving (which you'd have). There's a significant increase in chance of DCS for dives under 12 hours, with waiting 12 hours reducing the risk to one percent or less. And this is for regular flying, not an international flight, which increases the chances even more.

If you're not thinking about yourself, think about others. What if you get DCS symptoms on the international flight? It'll be an extreme hassle to everyone to turn around the flight to get you to a proper medical facility, just because you decided to take a risk.

Wait one extra day or skip the dive.

 

[redacted]

That 12 hour minimum is after a single dive. For multiple dives over multiple days, it jumps to 18 hours or more. And I believe it jumps again after decompression diving. I developed my no-fly routines after a series of trips to Cozumel and Bonaire by starting conservative and adding another dive or 2 after observing my gas loading status. Much better to note that you could have done one more dive than to find you did one too many.

 

[live_2_dive]

From a divers perspective: Absolutely don't do the dive on day 6. No question about it.

From a pilots perspective: if you're flying international, you will most likely be over an ocean for an extended amount of time. Once you're in the middle of the flight, it WILL be a long time before you can land somewhere in case of emergency (I've had to do it before, it sucks).

Also, in the cockpit we can regulate the cabin altitude. Many times when there is a screaming child, a pilot will simply raise the cabin altitude (causing the child to become slightly oxygen deprived and fall asleep). What does this mean for you? Even more risk of an emergency situation.

Bottom line: don't do the dive.


-------------------------------------------
PADI Rescue/DM 09100Z7445
Dr Dive/Wet Dream/Sea Cobra/Y-Knot/H2OBelow

Diving is my passion...I live to dive!

 

[fnfalman]

Decompression is not an exact science. You roll your dice and you take your chances.

Even if all of Scubaboard forum members were to agree with you, it still doesn't make you more or less susceptible to getting a DCS hit.

 

[soltari675]

Even though the dive is shallow and short, you are breathing on compressed air under pressure. This means that not only are you no longer off gassing, you are taking in MORE nitrogen. It will be a small amount at that depth and time, but you are taking in more and not getting rid of any from the previous full dive day. You would do better to snorkel/free dive on Day 6 and play it safe.

 

[Jim Lapenta]

From a divers perspective: Absolutely don't do the dive on day 6. No question about it.

From a pilots perspective: if you're flying international, you will most likely be over an ocean for an extended amount of time. Once you're in the middle of the flight, it WILL be a long time before you can land somewhere in case of emergency (I've had to do it before, it sucks).

Also, in the cockpit we can regulate the cabin altitude. Many times when there is a screaming child, a pilot will simply raise the cabin altitude (causing the child to become slightly oxygen deprived and fall asleep). What does this mean for you? Even more risk of an emergency situation.

Bottom line: don't do the dive.


-------------------------------------------
PADI Rescue/DM 09100Z7445
Dr Dive/Wet Dream/Sea Cobra/Y-Knot/H2OBelow

Diving is my passion...I live to dive!

Nice! So if on my next flight there is some screaming kid behind me I get the attendant to have the pilot drop the cabin pressure. Cool!

 

[flyandive]

Nice! So if on my next flight there is some screaming kid behind me I get the attendant to have the pilot drop the cabin pressure. Cool!

Woah woah,

I'll offer up an airline pilot perspective although I'm not sure what live 2 dive's background is other than the AF. Yes, we can manually adjust the cabin pressure but it increases our workload considerably (read: pain in the a**) and if we get distracted with something else it's easy to forget about until our ears start popping like crazy so for the most part manual mode is treated as a semi-emergency to be used only during a system failure and only as directed by our QRH (Quick Reference Handbook). Although we can depart or continue a flight in manual mode.

That's the official answer. That's not to say that it isn't something we might do occasionally (I have not, not worth it in my opinion) but there are some pilots who in the past may have done something along these lines. I can tell you If I got that request from a passenger I would just laugh and say "sure, I'll get right on that," stare at the panel for a bit and go back to doing whatever it was I was doing before.

As far as flying after diving the current recommendations from DAN based on their 2002 workshop are as follows:

12hrs for single dives
18hrs for multiple no deco dives
48+ for deco dives due to lack of information.

The FAA (Federal Aviation Administration) on the hand recommends 12hrs for a single dive and 24hrs for multiple dives. Their logic was based on the additional risk of DCS in the event of a loss of cabin pressure. All of DAN's research was based on 8,000ft cabin pressure altitude, which is the max allowed at an aircraft's service ceiling (normal cabin pressure is less than 8,000ft).

 

[boulderjohn]

As far as flying after diving the current recommendations from DAN based on their 2002 workshop are as follows:

12hrs for single dives
18hrs for multiple no deco dives
48+ for deco dives due to lack of information.

I am not sure where you got the 48+ hours.

From a FAQ on the DAN website:

The following guidelines are the consensus of attendees at the 2002 Flying After Diving Workshop. They apply to air dives followed by flights at cabin altitudes of 2,000 to 8,000 feet (610 to 2,438 meters) for divers who do not have symptoms of decompression sickness (DCS). The recommended preflight surface intervals do not guarantee avoidance of DCS. Longer surface intervals will reduce DCS risk further.

For a single no-decompression dive, a minimum preflight surface interval of 12 hours is suggested.
For multiple dives per day or multiple days of diving, a minimum preflight surface interval of 18 hours is suggested.
For dives requiring decompression stops, there is little evidence on which to base a recommendation and a preflight surface interval substantially longer than 18 hours appears prudent.

 

[redacted]

I am not sure where you got the 48+ hours.

From a FAQ on the DAN website:

The following guidelines are the consensus of attendees at the 2002 Flying After Diving Workshop. They apply to air dives followed by flights at cabin altitudes of 2,000 to 8,000 feet (610 to 2,438 meters) for divers who do not have symptoms of decompression sickness (DCS). The recommended preflight surface intervals do not guarantee avoidance of DCS. Longer surface intervals will reduce DCS risk further.

For a single no-decompression dive, a minimum preflight surface interval of 12 hours is suggested.
For multiple dives per day or multiple days of diving, a minimum preflight surface interval of 18 hours is suggested.
For dives requiring decompression stops, there is little evidence on which to base a recommendation and a preflight surface interval substantially longer than 18 hours appears prudent.

I'm not either. I meant to type 24.