Fill Up on Fluids
by Paul Engstrom, Aviation Writer and IFA Member
It was a hot
summer day as the private pilot, drenched in sweat, flew toward home
after numerous stressful landings at several airports. Suddenly, he
felt disoriented and spacey, and became alarmed when he couldn't
recall the number of the runway he had used hundreds of times at his
Only after this
pilot was safely on the ground did he pinpoint the culprit:
dehydration. His symptoms aloft, he recalled, were the same as those
he had experienced many times after grueling aerobic workouts at the
gym without drinking enough fluids.
aren't aware that prime-time flying'often during the warm or hot
months'is when dehydration can erode their dexterity, coordination,
ability to make quick decisions, alertness and visual capabilities, or
that it causes fatigue.
fewer are aware that many things besides hot weather can rob a body of
the fluids it needs to stay ahead of the demands of flying. They
Vigorous exercise before a flight
A warm cockpit
Diuretics'drinks like coffee, tea, alcohol and soda, which boost the
production and excretion of urine
A change in climate
Diarrhea and vomiting
normally lose 3 to 4 pints of water a day through sweating, breathing
and urinating, according to Dr. Richard Rinehart, a FAA senior
aviation medical examiner. That rate increases within minutes after
takeoff in a dry cockpit, especially if it's pressurized.
'And what's the
first thing you request after reaching cruise?' Rinehart says.
'Coffee, [caffeinated soda] or tea, all of which are diuretics'that
will exacerbate the problem.'
Keep in mind that
water makes up about two-thirds of body weight. It plays a crucial
role in cell division, transportation of nutrients, elimination of
wastes and regulation of body temperature. In a person who weighs 170
pounds, there are more than 10 gallons of water in and around the
cells and in the bloodstream.
individual physiology, temperature, activity level and other factors,
most people become thirsty after they shed around 1.5 quarts of water,
or 2% of total body weight, says Rogers V. Shaw, team coordinator of
the Airman Education Program at the Civil Aerospace Medical Institute
in Oklahoma City, Okla.
The problem, Shaw
notes, is that the thirst mechanism 'arrives too late and is turned
off too easily.' In other words, a pilot might already be dehydrated
by the time he or she realizes it and may consume too little fluid to
serious enough that in 2002 the FAA added it to the list of
aeromedical factors about which student pilots must be familiar in
order to meet the Practical Test Standards for a private license.
The danger hasn't
gone unnoticed in commercial aviation circles either. Dr. Don Hudson,
an aeromedical adviser to the Air Line Pilot Association, emphasizes
dehydration risks in meetings with pilots who fly for a living.
This doesn't mean
you have to make rehydration a science, calculating down to the fluid
ounce how much water you'll need. The Federal Air Surgeon's Medical
Bulletin simply advises drinking lots of cool water, not waiting until
the thirst sensation kicks in and avoiding diuretics. Having an ample
supply readily accessible before and during a flight will probably do
If bottled water
is too unpalatable, try a sports drink like Gatorade. These drinks
contain electrolytes'potassium, calcium and sodium'that muscles and
nerves rely on for carrying electrical impulses. Sodium also helps the
body retain fluids.
The bottom line:
Fly safe'and never pass up an opportunity to consume fresh water.
When he isn't
flying, Paul Engstrom writes and edits from Sebastopol, Calif.