descending

[weather289]

I recently traveled to Houston from Pittsburgh this weekend. The flights were fine, some rough turbulence on the way down and coming back saw some nice cloud structure. Anyway when we were descending into PIT I got a sharp pain behind my ears and my right here still hasn't "popped." When I went to our school's health services the nurse looked in my ear and saw blood against my ear drum...anyone know why the descent would have caused such a reaction? I've flown a number of times and this is the first time I've had physical problems from descent.

--Bill

[lnuss]

You probably had some sort of blockage in your sinus cavities or inner ear. Perhaps you had a cold. Altitude changes mean that you are going from high to low or (descending) from low to high pressure. The various passages inside your head tend to retain pressure, and you must sometimes make a concious effort to equalize the pressure as you change altitude. When you have a cold, or sinus condition, or allergy blockage, it becomes very difficult to equalize that pressure, which is why it's usually not a good idea to fly with such conditions.

To give you an idea of the pressure and forces involved, the air at sea level is typically near 15 pounds of pressure per square inch of surface. At 18,000 feet it is roughly half that. In a pressurized airliner at, say, 35,000 feet (FL 350), the cabin pressure may be around 7,000 to 10,000 feet equivalent altitude, which is a considerable change in pressure. If you had an empty plastic milk jug with the cap sealed just before they pressurized the aircraft on the ground (and assuming it didn't leak), by the time you reached cruising altitude you would see a considerable squashing of that milk jug -- it may even totally collapse. That same kind of pressure change is happening in your ears/nose, and can exert rather considerable force. You're not the first to have that happen, and you won't be the last.

[HR]
Larry N.

http://www.flightsim.com/dcforum/User_files/3dd4657454c071bd.jpg

[Icarus747]

What Larry said above was right so I won't comment. BUT.... to avoid this in the future:

1. Chew gum.

2. Move your jaw from side to side.

3. Swallow.

Doing these three things in order over and over agin should help you equalize. All three help wiggle around your eustacian tube (god did I spell that right?) which is where the pressure is building

Sudaphed before a flight can help keep your passages open and it's legal to take as a flight crewmember.

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[Rockcliffe]

Hi Larry:
Is that right about the milk jug?
I would have thought that sealing the jug on the ground would give it positive pressure at altitude (sea level, 15 psi inside vs. the cabin pressure of 7,000 to 8,000 ft pressing from outside), causing the jug to expand rather than be crushed.
Blair
CYOW

[toddrf]

You are correct. If you are at sea level and you seal that milk jug and then go to altitude it will expand and perhaps even blow the top off.

If however you open the milk jug at cabin altitude in cruise, the equivalent of say 8000 feet and then reseal it and head for earth, when you touch down the jug will be nicely squashed.

The same think happens in submarines as well when they descend too far.

No matter, the effect is the same on your eardrum. If you have an unrelieved pressure differential across the drum, at some point the variance will exceed the rating of your eardrum and something will give. Likely a rupture with a brief sharp pain and then, thankfully relief.

Sinuses on the other hand are not soft and squishy, they are hard and bony and usually you end up with a heck of a headache and a greatdeal of pressure.

Sudafed, Motrin three days before flying, gum and lots of water on the day of and sudafed and Motrin three days after. You should be okay.

Todd :-wave

[lnuss]

Ooops! I got a couple of things reversed -- nice catch, Blair. Yes, it should have been on the descent that the jug would crush. It would expand with the climb. Sorry - I've been fighting some software, and my mind still isn't untangled.

Thanks,

[HR]
Larry N.

http://www.flightsim.com/dcforum/User_files/3dd4657454c071bd.jpg

[Rockcliffe]

By my count that drops your average to 1,859 out of 1,860, Larry. Still not too shabby.
It's always a joy to read your posts.
Regards
Blair

[Rockcliffe]

Another question... Is that why flight attendants won't let you open your own can of pop on an airliner?

[flyinggriffin]

Your ears pop pretty easy on ascent because the air pressure inside is greater than outside. On descent the opposite is true and the eustacian tube if its blocked a little can even collapse.

If you are ever in a light plane and you feel pain, sing out loud and right away. We have a lot more leeway to slow our descent or even go back up again and come down slowly than a commercial plane trying to make a schedule.

[toddrf]

Does airline pop reside in a pressure chamber kept at altitude? Airline pop is canned in the same plant as your pop. If they have any gripe about you and your pop it must be personal.

Did someone actually give you a hard time about your own pop? If so, the system is really doomed.

Todd :-wave

[Rockcliffe]

Let me clarify. Things are fine between my pop and me :-).
So the question is: If a liquid is bottled or canned at ground level, when opened at altitude is it more likely to spray?

[toddrf]

If you popped the top at 50,000 feet in an unpressurized cabin you would likely see dramatic results. It might well vaporize itself.

But the atmospheric pressure at an 8000 foot cabin altitude is not all that much less than it is at sea level (if it was then people would be passing out right and left from hypoxia. Purists might respond to this with an elaborate discussion of partial pressures and absolute atmospheric pressures at altitude, but in the case of pop and human blood it is really irrelevant) so in practice the pop might be slightly more lively, but not so much that anyone other than an extreme carbonation-phile would notice.

Kind of like the argument between CD and vinyl. Which is better?

I mean the same question is posed; is pop more likely to spray out of the can in Leadville, Colorado than it is in Washington DC?

Now if you could can the pop in the Mariana's Trench and then bring it to the surface without it exploding, it might be really fun to pull the tab.

Glad you and your pop get along well....

Todd :-wave

[Rockcliffe]

Thanks Todd.

[weather289]

Well, turned out to be an ear infection. Doctor said the descent in the plane or cabin pressure was not a factor, just a coincident the pain started at that point in time. Just two weeks on some prescriptions and life will be good again...thanks to those who responded!

--Bill

[newguy]

well how about that? A complete education for on the working of air pressure all for an ear infection...



"How much deeper would the ocean be if sponges didn't live there?"

[robbie1472]

Wasn't singing out loud good for something else? Oh yea, hyperventilation. :-)

[flyinggriffin]

If a passenger were to chug-a-lug down a whole can of soda(pop)just before hopping into a light plane and then go to say 10,000ft I wonder if things would get A. somewhat painful for the person or B. Loud and disgusting.