If you fly an
un-pressurised aircraft, you are almost sure, eventually to encounter
the problem of ear discomfort during ascent or descent. To understand
why this happens and how to counteract it, a simple grasp of the
structure of your ear is helpful.
The external ear canal
(the small tube leading to your eardrum) is always at the same pressure
as the atmosphere surrounding the body. The middle ear, where pressure
problems arise, is a small air-filled cavity situated within the bone of
the skull and it is separated from the external ear canal by the eardrum
- a thin membrane. The other side of the middle ear is connected to the
nasal cavity by the Eustachian tube.
As your aircraft gains
altitude, the atmospheric pressure decreases and so does the pressure in
the external ear canal. The middle ear, being an enclosed cavity, stays
at ground-level pressure. When the pressure in the middle ear exceeds
that of the external ear canal, your eardrum starts to bulge outward
somewhat. The middle ear is sensitive to this change and requires only a
slight excess of pressure to open the Eustachian tube so that gas may
pass by this route through the nose or mouth. In this way, pressure is
equalized on both sides of the eardrum. You may be aware of this
pressure change by alternating sensations of ear fullness and
conditions within the ear are reversed. As the surrounding air pressure
increases, the middle ear - which has accommodated itself to the reduced
pressure at altitude by the process just described - is at a lower
pressure than the external ear canal. consequently, the outside air
forces the eardrum to bulge inward. This condition is much more
difficult to relieve, since air must be introduced back up the
Eustachian tube to equalize the pressure. The partial vacuum in the
middle ear also tends to collapse rather than inflate the walls of the
Eustachian tube. You can best remedy this by closing your mouth,
pinching your nostrils shut, and blowing slowly and gently to build up
pressure in your mouth and nose. At some point in this procedure, you
will be able to feel air entering the middle ear, and you will notice an
immediate improvement in your ability to hear. This will be followed by
a relief in the sense of fullness and discomfort.
Should you find that you
cannot clear your ears in flight, as just described, consult a physician
immediately after landing. It may save you weeks of trouble. The AME can
quickly and painlessly solve the problem.
If you have a cold, the
tissue around the nasal end of the Eustachian tube will probably be
swollen, and you can expect ear problems to be aggravated in flight. The
best advice is to stay on the ground. If you must fly, do so at lower
altitudes. This precaution may prevent a perforated or painful eardrum.
Although a perforated eardrum general heals rapidly, in some cases
hearing is impaired permanently or the middle ear becomes infected and
causes prolonged disability.