Flying after 20ft dive

[Asteve]

I find it amazing/sad that with scuba having been around for more than 50 years we still do not know the answer to this simple question.

 

[Bob DBF]

One could work out the pressure difference between 20' and cabin pressure of, say, 8000' (assuming the plane does not crash and burn killing everyone on board), and see if it's over 2/1 or not.

It isn't whether the plane crashes and burns, but whether it looses cabin pressure and has the cabin pressure jump to 20,000'.

I find it amazing/sad that with scuba having been around for more than 50 years we still do not know the answer to this simple question.

Risk management is not a simple question, and that is the question as there are already a number of written guidelines. Also there ase personal theories on why one could shortcut those guidelines.

Since personal psyology has a lot to do with decompression, one has to make a choice on what strategy best suits your situation. From my teens to 30's I would push the limit a bit, and saw some divers ignore the tables and get away with it, but I didn't because I did not believe myself that lucky. When I had a family, I got a bit more conservative (for me), and now that I'm even older, I've become more conservative in my choices. What this means is that I now use the dive to fly time on my computer or usually longer.


Bob
"...you've gotta ask yourself one question: "Do I feel lucky?" Well, do ya, punk? Harry Calahan

 

[dmaziuk]

It isn't whether the plane crashes and burns, but whether it looses cabin pressure and has the cabin pressure jump to 20,000'.

I've a feeling they don't "just" lose cabin pressure out of nowhere, chances are there's more fecal matter on its way to the fan blades when that happens.

 

[boulderjohn]

There is always a risk in everything we do. We calculate the risks and decide if we want to do whatever we are planning to do. Everytime we drive a car we are running a pretty big risk, but we choose to do it anyway, because we decide that even that risk is too low to worry about.

I have no idea how many airplane flights I have taken over the decades. I have no idea how many flights my friends and family have taken over the decades. I don't know anyone who has ever mentioned being on a flight when the cabin has become depressurized. I suspect the odds of that happening are pretty low. When I plan to fly after diving, I don't give that possibility any more thought than I worry about an accident if I drive to the store for a loaf of bread.

 

[dmaziuk]

We drove up Mt Kea (14,000) after and hour or so at the visitors centre (9,000) and both my BH and I felt a little off for a while at the top. I suspect plane cabin decompressing from 6 to 20K feet, and much faster, isn't going to be pleasant with or without diving.

 

[dberry]

There is always a risk in everything we do. We calculate the risks and decide if we want to do whatever we are planning to do. Everytime we drive a car we are running a pretty big risk, but we choose to do it anyway, because we decide that even that risk is too low to worry about.

I have no idea how many airplane flights I have taken over the decades. I have no idea how many flights my friends and family have taken over the decades. I don't know anyone who has ever mentioned being on a flight when the cabin has become depressurized. I suspect the odds of that happening are pretty low. When I plan to fly after diving, I don't give that possibility any more thought than I worry about an accident if I drive to the store for a loaf of bread.

Funny you should say that... I was going to mention the scene from "Goldfinger" when the bad guy is sucked out the window. But then I remembered a month or two ago we heard about a jet engine failing, sending shrapnel through a passenger's window. She was partially sucked out the window, with fellow passengers trying to pull her back in. She died, although it certainly wasn't because of DCS.

In any case, I agree with BoulderJohn's point about everything having some level of risk, so don't sweat the things you have no control over.

 

[dmaziuk]

Yes, the one case anyone's ever heard of, and the poor woman wouldn't have been any worse off if she'd dived just before her flight.

 

[johndiver999]

I don't understand altitude diving, but the if the computer "thought" you were diving at an elevation of 8,000 ft and gave you a NDL that you did not exceed, then that means you can get out of the water (at 8,000 ft) and be OK correct?

So why is that different than getting on an airplane that will be pressurized to 8,000 ft - assuming no accidental loss of cabin pressure?

That seems to be the most objective means to quantify the situation. Am I missing something?

The several hour wait before boarding the aircraft would also seem to be huge safety buffer.

 

[boulderjohn]

I have to admit I don't understand why diving altitude NDLs makes a difference.

 

[dmaziuk]

Theoretically, instead of surfacing with "safe enough for 1 atm" gas loading, you'll surface with "safe enough for 0.8 atm" (or whatever). Gotta wonder how much difference that'd be on a 20' dive.