A320 Pressurization 'peaks' cause damage to body? (packless tkof)
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Pressure changes in a commercial aircraft are trivial compared with those experienced by a SCUBA diver. Water being 800 times more dense than air.
SCUBA instructors and dive guides have now spent decades exposing themselves to this several times a day with no physiological harm so long as recommended procedures are kept to.
SCUBA instructors and dive guides have now spent decades exposing themselves to this several times a day with no physiological harm so long as recommended procedures are kept to.
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The OP's fishing for some to-date unknown damage caused by an insignificant but routine event smells to me of an ambulance-chasing lawyer's mentality, and one who knows nothing of human physiology either.
As said above, what about scuba? Trains going through tunnels (the underground, for instance where something very like this but much, much stronger happens many times per hour), high speed lifts?
As there is no evidence whatsoever to back up this fanciful speculation - and pressure has been researched endlessly over many decades by medical and aviation science (who would doubtless be quietly chortling at the idea) , I suggest this topic is done and dusted, or consigned where it belongs, to Jetblast.
Before the Daily Mail gets hold of the idea that professional pilots (ha!) are worried about it...
As said above, what about scuba? Trains going through tunnels (the underground, for instance where something very like this but much, much stronger happens many times per hour), high speed lifts?
As there is no evidence whatsoever to back up this fanciful speculation - and pressure has been researched endlessly over many decades by medical and aviation science (who would doubtless be quietly chortling at the idea) , I suggest this topic is done and dusted, or consigned where it belongs, to Jetblast.
Before the Daily Mail gets hold of the idea that professional pilots (ha!) are worried about it...
PH-Chucky, think of it this way: If you jump into a pool down to 1 meter, you just increased your pressure by 10% in less than a second. That's about 3000' of air pressure change in less than a second, or >180 000' feet per minute.
So anyone worried that a 1000' pressure change in 60 seconds could be a problem should certainly be careful getting into the bath. I'd suggest slowly lowering yourself into the bathtub over 2 minutes minimum, preferably 3.
Can't be too careful.
So anyone worried that a 1000' pressure change in 60 seconds could be a problem should certainly be careful getting into the bath. I'd suggest slowly lowering yourself into the bathtub over 2 minutes minimum, preferably 3.
Can't be too careful.
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NEW EXCITING FUEL-SAVING MEASURE.
Wearing my beancounter/management hat I have the following suggestion:
1) Both packs OFF til 10,000 ft, that should save a kg of fuel or two, whilst taking the strain off the engines IAW power-by-the-hour or wotever.
2) First pack ON @ 10,000 ft, this would avoid the erroneoues flap retraction risk as by then I'd hope they were safely tucked away. The reduced air density would lessen the "submarine" effect compared with sea level compression.
3) Second pack on at 25,000 ft, save more kgs of fuel and protect against the effects of losing the 1st pack, 1 pack flight up to FL250 apparently OK according to DDGs various.
4) One pack off in descent through FL250, save fuel and pack wear and tear, maybe swop which pack like engine ignitors to even out the wear and increase the chances of both failing at the same time, just like the ignitors did on me years ago.
5) Leave the remaining pack ON til touchdown as a gesture to the SLF that we really do care about their comfort.
Another advantage of the reduced packs climb is it would accelerate the expulsion of gases from the body cavities of both SLF and crew, clearing the mucus from the sinuses and blowing the plugs out of the eustacion tubes, thereby making for an easier and less painful descent.
Should any airline management adopt these procedures, I will of course expect a cut of the savings which could be considrable?!
1) Both packs OFF til 10,000 ft, that should save a kg of fuel or two, whilst taking the strain off the engines IAW power-by-the-hour or wotever.
2) First pack ON @ 10,000 ft, this would avoid the erroneoues flap retraction risk as by then I'd hope they were safely tucked away. The reduced air density would lessen the "submarine" effect compared with sea level compression.
3) Second pack on at 25,000 ft, save more kgs of fuel and protect against the effects of losing the 1st pack, 1 pack flight up to FL250 apparently OK according to DDGs various.
4) One pack off in descent through FL250, save fuel and pack wear and tear, maybe swop which pack like engine ignitors to even out the wear and increase the chances of both failing at the same time, just like the ignitors did on me years ago.
5) Leave the remaining pack ON til touchdown as a gesture to the SLF that we really do care about their comfort.
Another advantage of the reduced packs climb is it would accelerate the expulsion of gases from the body cavities of both SLF and crew, clearing the mucus from the sinuses and blowing the plugs out of the eustacion tubes, thereby making for an easier and less painful descent.
Should any airline management adopt these procedures, I will of course expect a cut of the savings which could be considrable?!
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Quote:
"Packs off is the manufacturer's SOP. (In Airbus' case anyway.)"
If you review the Airbus A318/319/320/321 FCOM Section PRO-NOR-SOP -11 P 1/2, you will see that the above comment is incorrect!
The Airbus Pack procedure as listed in the SOP - "Before takeoff" is: Packs 1 and 2 ....... AS REQD
"Packs off is the manufacturer's SOP. (In Airbus' case anyway.)"
If you review the Airbus A318/319/320/321 FCOM Section PRO-NOR-SOP -11 P 1/2, you will see that the above comment is incorrect!
The Airbus Pack procedure as listed in the SOP - "Before takeoff" is: Packs 1 and 2 ....... AS REQD
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If airbus design life and inspection schedules are based on a say 75% packs on and 25% pack off take-offs, and operators ask us to make 100% packs off take-offs, there is the seed of a doubt re this as a lifetime procedure for these aircraft.
Hard to think that it is serious in the short term, and most of these operators will no longer lease them when these aircraft are near the end of their life. So why should they care?
Hard to think that it is serious in the short term, and most of these operators will no longer lease them when these aircraft are near the end of their life. So why should they care?
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If airbus design life and inspection schedules are based on a say 75% packs on and 25% pack off take-offs, and operators ask us to make 100% packs off take-offs, there is the seed of a doubt re this as a lifetime procedure for these aircraft.
Pilots with ear problems can be replaced by cheaper P4T/P2F pilots, but engines, maintenance and fuel still cost money.
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As mentioned in post 28 above, if you are worried about a momentary peak of 1000 fpm, DO NOT EVER GO FOR A SWIM IN A POOL. Snorkeling would sure be lethal! Even taking a bath or an elevator ride will have serious consequences to your health. DO NOT BLOW YOUR NOSE. Do not sneeze. And if you hear a loud noise, don't cover your ears! Don't burp. Don't fart. Don't laugh. Don't speak to your wife. These could all induce +/-1000 fpm pressure chances!!
And as for SCUBA, has anyone ever survived that?
And as for SCUBA, has anyone ever survived that?
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1000 fpm?
Years ago a relative of mine worked in the World Trade Center tower #1 (fortunately he changed jobs before that bad day). He and a whole lot of other fellow office workers used to do 1000 feet in a minute in the elevator everyday - no big deal.
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2) Is the Automatic Pressure Control Mode doing it's work correct when "Packs Off" tkof is used?
I am asking this because I noticed on our aircraft a very high v/s (-1000ft) of cabin rate after the first pack is switched on.
I am asking this because I noticed on our aircraft a very high v/s (-1000ft) of cabin rate after the first pack is switched on.
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PH chucky We put one back on and then the other.
Ocean crosser By doing this we save on fuel (multiply by how many sectors in a week x 52 weeks) over a year this adds up!
Also - if the engine manufacturers lease the engines then they probably have a stipulation in the contract, that demands packs off until x,000 ft.
Ocean crosser By doing this we save on fuel (multiply by how many sectors in a week x 52 weeks) over a year this adds up!
Also - if the engine manufacturers lease the engines then they probably have a stipulation in the contract, that demands packs off until x,000 ft.
I'm probably being dense here, but how can switching the packs back on at thrust reduction altitude cause an early retraction of flaps/slats???
Packs off T/O is SOP with us. It saves fuel - Pax want the cheapest fare; QED.
I didn't know about the pressure strengthening the fuselage, but surely at take off there is not much differential pressure, so this effect will be minimal near the ground?
Packs off T/O is SOP with us. It saves fuel - Pax want the cheapest fare; QED.
I didn't know about the pressure strengthening the fuselage, but surely at take off there is not much differential pressure, so this effect will be minimal near the ground?
