
Vida> Can one develop inner-ear problems from too much flying?  I hear
Vida> that pilots and steward/esses have a limit as to the maximum
Vida> number of flying hours -- what are these limits?  What are the
Vida> main problems associated with too many long-haul (over 4 hours)
Vida> trips?

The crew rest requirements are to prevent undue fatigue.  The cockpit
crew (pilot) limits are somewhat more stringent than the cabin crew
limits for this reason.  Crew rest requirements address amount of time
on duty plus rest time.  A tired crew is an accident-prone crew.

The only limits I know of for inner-ear problems are in military
aircraft, which are frequently unpressurized or less reliably
pressurized.  Not being able to clear the ears renders aircrew members
DNIF (duties not involving flying) or grounded until the ears clear.

Flying can accentuate problems if ears don't clear.  If you don't have
big pressure changes, you may not know that you've got a problem.  But
if you zip up to 5,000 or 6,000 ft (the usual cabin altitude in an
airliner) and then back down to sea level, you may discover a problem.
Ears don't clear readily because of allergies, colds, infections, and
anatomical problems.  The last won't change; the first three can.
Medication (decongestants or antihistimines, usually) can help.
Chewing gum, sucking hard candy (or a bottle for babies),
yawning--these will help all four causes.

