Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/17/84; site bcsaic.UUCP
Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxt!houxm!mtuxo!mtunh!mtung!mtunf!ariel!vax135!cornell!uw-beaver!ssc-vax!bcsaic!ted
From: ted@bcsaic.UUCP (ted jardine)
Newsgroups: net.aviation
Subject: Re: Sinus troubles
Message-ID: <189@bcsaic.UUCP>
Date: Sat, 13-Jul-85 21:40:15 EDT
Article-I.D.: bcsaic.189
Posted: Sat Jul 13 21:40:15 1985
Date-Received: Thu, 18-Jul-85 04:48:29 EDT
References: <830@rayssd.UUCP> <103500001@uiucuxc>
Reply-To: ted@bcsaic.UUCP (ted jardine)
Organization: Boeing Computer Services AI Center, Seattle
Lines: 27

Though it may seem trivially obvious, sinus and ear problems on descent are
caused by the rate of change of 'cabin' pressure being greater than the rate
at which the sinus or ear can adapt to the change.  The problem is more
frequently encountered on high performance aircraft, especially airline
aircraft, because of pressurization and their high rate of descent.  A rate
of descent of more than 3000 fpm is not uncommon until reaching the initial
approach fix.  I'm no expert on pressurization systems, but I know that they
are designed to maintain a 10,000 foot cabin pressure above that altitude and
then ambient pressure (perhaps at a lower rate of change) below 10 thousand.
The rate of change in a smaller airplane is not nearly as great, perhaps
500-1,000 fpm.  Using an antihistamine and an inhaler is appropriate for
anyone with unusual sinus difficulties, as it keeps the passages into the
sinus cavities and the ear as clear as possible.  Also useful is a procedure
called the Valsalva (sp?) method, in which you close your mouth, pinch your
nose shut and forcefully exhale.  Using this several times during descent
will clear up almost all ear problems and many sinus problems will at least
be reduced, if not disappear.  In the good old days, long before deregulation,
the flight attendants used to have antihistamine inhalers, but that practice
has been abandoned.  For small children, giving them something to suck on
before and during the descent is often very helpful.  One of the side effects
of a baby crying is to open up the Eustachian tube which alleviates the pain.
Just 'tricks' I've learned bouncing around up there.

TJ (with Amazing Grace) The Piper
(aka Ted Jardine)
Boeing Artificial Intelligence Center
...uw-beaver!uw-june!bcsaic!ted