Cockpit lighting has
been the subject of considerable discussion. In military aviation, red
lighting was long used in the cockpit and pilots were required to wear
red goggles for a certain period of time before night flight. These
precautions for night adaptation were necessary because pilots who
needed to spot enemy aircraft frequently flew from inadequately lighted
airports and navigated by vision more than by instruments.
With the advent of
adequately lighted airports and the general use of radio for navigation,
"night vision" actually became less important. The tendency now is
toward more complete illumination of the cockpit, with white light used
more than red. Problems such as improper fuel selection and errors in
course plotting or chart reading are much more significant now than the
loss of night vision. Still, you should be familiar with a few facts
about visual adaptation during night flying.
Your eyes need about
30 minutes to adjust to maximum night efficiency after exposure to
Bright lights (such as landing lights) knock out night vision,
requiring you to "night-adapt" all over again to regain maximum night
vision. Closing one eye when you are briefly exposed to bright light
(while map reading, for instance) may protect that eye so it need not
Lightning flashes knock out night vision. Therefore, near storm
clouds, turn up the cockpit lights to see your instruments properly.
Remember to remove your sunglasses after sunset, or you may find
yourself flying in "instrument conditions" when actually the ceiling and
visibility are normal.