New aircraft =shorter fly time?

[tbone1004]

oh, your other option for all of this is to actually conduct the last dive of the day as an altitude dive. Means getting off of the computer, and running vplanner, but you can factor the flying into your decompression times. Not condoned or recommended by me, but it's an option if you are really in a pinch for whatever reason.

 

[Cosimo_Zaretti]

oh, your other option for all of this is to actually conduct the last dive of the day as an altitude dive. Means getting off of the computer, and running vplanner, but you can factor the flying into your decompression times. Not condoned or recommended by me, but it's an option if you are really in a pinch for whatever reason.

Would you base the air pressure on the expected cabin pressure, the plane's actual altitude, or split the difference? My concern wouldn't be so much flying in an aircraft pressurised to 6000 feet after a series of no stop dives, it would be a worst case scenario where the aircraft lost cabin pressure.

 

[KeithG]

Would you base the air pressure on the expected cabin pressure, the plane's actual altitude, or split the difference? My concern wouldn't be so much flying in an aircraft pressurised to 6000 feet after a series of no stop dives, it would be a worst case scenario where the aircraft lost cabin pressure.

good point.
is the no fly time based upon what can happen to you if you go up to 8,000 feet
OR
does it assume worst case and is based upon what will happen to you if you go up to the aircraft flight altitude?

if it is based on the first, then you could expect some issues if the air cabin depressurized even if you wait the recommended time?

 

[dumpsterDiver]

If you find yourself in an unpressurized aircraft at cruising altitudes, you have bigger problems than the bends..

 

[hroark2112]

I always enjoy getting out of the water, grabbing a quick shower, packing my gear & then hitting the airport.

Love leaving a puddle in the waiting room from my carry-on dripping

 

[sharkbaitDAN]

I flew the Dreamliner from Seattle to Narita, our cruising altitude, according to the inflight map, was 42,000 ft. So it may be cheaper to pressurize the cabin more because they can use that to fly at a higher altitude and maintain an 8000 ft cabin. Pressurized to a lower altitude sounds great in marketing materials, though.

 

[KeithG]

the answer to my question is that DAN tested to simulated 8000 feet, not the unpressurized altitude of the aircraft.
https://www.diversalertnetwork.org/research/projects/fad/index.asp

 

[scubadada]

I'm a simpleton, I try to wait 18 hours and/or until my computer tells me I'm entirely desaturated. So far, so good. I would not adjust this according to the plane I'm flying

 

[scagrotto]

Would you base the air pressure on the expected cabin pressure, the plane's actual altitude, or split the difference? My concern wouldn't be so much flying in an aircraft pressurised to 6000 feet after a series of no stop dives, it would be a worst case scenario where the aircraft lost cabin pressure.

Not sure why, but I've long been under the impression that the long time before flying is significantly conservative, and partially related to the possibility of exposure to cabin pressures below the typical 8000'. The lower pressure could be be from flying in non-pressurized craft, as well as a mishap in pressurized craft.

The pressure at 8000' is about 75% of sea level pressure. I don't know a lot about deco theory, but I'm pretty sure that 12 hours will let a 720 minute tissue lose half of its N2 load, and that offgassing 50% will allow you to further reduce ambient pressure by 50%. Thus if you weren't bent at 1ATA on the surface you shouldn't get bent by flying 12 hours later even if the cabin pressure drops to 60% of sea level pressure. OTOH, lose cabin pressure anywhere above about 18,000 and pressure may drop below 0.5ATA. Even then, unless that slowest tissue was close to saturation you should have a bit more leeway. Of course it's called deco theory, and not everyone reacts the same way to any given compression/decompression cycle.

As noted above, planes lose cabin pressure on a fairly regular, though infrequent basis, usually with fairly minor consequences. Typically the problem is easily and quickly solved by a rapid descent, and that means that pressure will be restored to 8000' (or something close) pretty quickly. That would mean that getting bent is still pretty unlikely. Like all the non-diver passengers the bigger risk is that an abrupt depressurization could result in the sort of barotrauma we normally avoid by not holding our breath.

 

[bygolly]

If you find yourself in an unpressurized aircraft at cruising altitudes, you have bigger problems than the bends..

True....but you would have all of the problems everyone else has PLUS the bends.