"no fly" time

[Thalassamania]

Techniques for flying without waiting is kind of like jaywalking. You know its wrong, but you need to save the time, and done with care you can get across the street safely. Done without thinking, without looking both ways several time, just darting out from between two parked cars ... well ... that's another story. The problem is that most of the authorities, because of liability issues, can't give you the information that you need to make an informed judgment, so you learn about it hanging out on some cyber-corner, just as your parents feared.

 

[Dr Deco]

Hello Readers:

There is in actuality a time interval between decompression and tissue nuclei growth. This results from the requirement for dissolved nitrogen molecules to diffuse from tissue to the nuclei. In an airplane, one can use this duration to advantage by descending.

The estimated duration to DCS at 40,000 feet is only a few minutes [see attachment]. As the plane descends, one will gain on this bubble growth and actually reach 15,000 feet in only a few minutes.

The graph was prepared for an FAA workshop and is for individuals saturated at sea level. Divers would be in a more hazardous position.


Dr Deco :doctor:

 

[Bismark]

Hello Readers:

There is in actuality a time interval between decompression and tissue nuclei growth. This results from the requirement for dissolved nitrogen molecules to diffuse from tissue to the nuclei. In an airplane, one can use this duration to advantage by descending.

The estimated duration to DCS at 40,000 feet is only a few minutes [see attachment]. As the plane descends, one will gain on this bubble growth and actually reach 15,000 feet in only a few minutes.

The graph was prepared for an FAA workshop and is for individuals saturated at sea level. Divers would be in a more hazardous position.


Dr Deco :doctor:

Would this also be the scientific reason why various agencies tell us you have as much as 5 minutes on the surface to deal with a problem if S**t hits the fan on a deco dive before you have to get down to your deco depth again? (or deeper) What are your thoughts on this 5 minute "rule"? Too long? Too short?

 

[Dr Deco]

Hello Bismarck :


This lag in tissue bubble growth does afford one the luxury of descending again if decompression is missed.

In the world of professional diving [and military], this is called “decanting” and is a procedure employed to reduce the duration of decompression where the diver is in a cold suit. The diver is brought to the surface, suit removed quickly, led to the chamber, and then recompressed; the decompression phase completed in a warm environment. Because he is in the chamber, the driver is dry, can sleep, is back on board ship rather than dangling over the side, and can be attended if DCS becomes an issue.

Coordination is important so that the time on deck at sea level pressure is short.

Dr Deco :doctor: