About one-tenth of all general aviation
accidents occur at night, while fewer than 10 percent of the flying is
done after dark.
Presuming that night flying is more dangerous
than day flying on the basis of statistics is a fallacy. The airplane does
not discriminate between light and dark.
Conditions of night flight are different from
daytime flying and it is the pilot's knowledge, or lack of it, combined
with a lack of visual clues that present an extra challenge.
A pilot may be subjected to times when the
destination airplane lies beyond the rays of the setting sun. Perhaps an
engagement becomes a compelling reason to venture out into the black of
Flying at night in the mountains is a matter
of determining the weather condition to arrive at a personal go/no-go
For those who decide to fly at night, an
understanding of night vision differences and adjusting the flight
operation accordingly, will increase the margin of safety.
Even a competent attitude-instrument pilot
will need to use his outside vision during a night flight, if only in the
transition during takeoff and landing.
What you see, or don't see, in the dark is
dependent on the state of dark adaptation of your eyes.
If you enter a dark area, your vision
improves slowly. After six to seven minutes the eyes are 100 times more
sensitive than when you entered the dark. Full adaptation takes 30
minutes, at which time the rods of the eye are 100,000 time more
This is due to the build-up of a
photosensitive chemical called visual purple, the key to night
vision. Visual purple is dependent on vitamin A (carrots, eggs, milk,
cheese and most vegetables). Vitamin A cannot be stored by the body; it is
necessary to eat well-balanced meals before night flying.
Although it takes 30 minutes for dark
adaptation to occur, it can be lost in a second or two of exposure to
bright light. Minimize the use of white light in the cockpit and keep it
as dim as possible.
Dark adaptation is an independent process in
each eye. If you are exposed t light, close one eye to preserve half your
The cones of the eye, used for day vision,
provide peripheral vision. Night vision uses rods. This creates a blind
spot in the centre of the eye at night. If you detect something with
peripheral vision, the natural tendency is to turn and look directly at
it. Night vision is impossible at the centre of the eye, so a technique
called "off-centre scanning" must be developed. Look six to 12 degrees
away from the object you wish to see.
A visual illusion may occur at night if you
stare at one light for a long period of time. Involuntary muscle twitches
cause the light to be displayed on a different portion of the eye,
creating false motion, where the light appears to move. Avoid autokinesis
by the off-centre scanning technique.
night take-off and
Before departing from a mountain airport at
night, firmly fix in your mind the nature of the terrain and obstructions
adjacent to the airport.
Pilots have no intention of making an
emergency landing shortly after takeoff, especially at night, but it does
not hurt to survey the terrain during daylight conditions to form a plan
With the interior lights adjusted to the
minimum brightness that affords instrument readability, initiate a normal
Acceleration error in the attitude indicator
will cause an indication of a higher nose attitude than during a regular
climb. As a consequence, some pilots have lowered the nose to the normal
attitude and have flown into the ground.
The moment the airplane leaves the ground on
a dark night, it is enveloped in black. Outside visual reference becomes
impossible. Maintain a positive rate of climb based on the airspeed
indication, regardless of the attitude indicator display.
If you become disoriented during the climb
out, terrain clearance becomes a big concern. Fly toward the rotating
beacon. At airstrips without lighting, fly toward any light on the
Proper pre-flight planning includes studying
charts and developing a plan of action. Still, at some time during a night
flight, you are going to experience a moment of fear arising from your
concern about terrain clearance.
If there are any light around, use them. Fly
directly toward the light. As you approach this light, select another
light. If the light flickers or disappears, there is something between you
and the light. Immediately choose another light to fly toward.
If there is only one usable light in the
area, a shuttle climb in a holding pattern may be the most prudent course
To perform a shuttle climb, make a 90-degree
turn (direction depends on obstructions) and immediately turn the opposite
direction for 270 degrees. This is the same as a 180-degree turn, but
keeps the airplane confined to a small geographical area.
Before passing beyond the ground light,
perform a 180-degree turn back to the ground light. Continue this
manoeuvring while climbing to a safe en route altitude before proceeding
It is difficult to see and avoid weather at
night. The first indication of a cloud may be a glow emanating from the
navigation lights, or a brilliant flash of the strobes being diffused
throughout a cloud.
VFR pilots should do an immediate 180-degree
Restricted visibility conditions become
apparent with the gradual disappearance of lights on the ground or when
they become fuzzy and flow.
Remember, the horizontal visibility through a
restriction such as fog, haze or smoke is must less than when looking down
through it from above.
Pilots get into trouble trying to land at an
airport with fog because they fly over and can see the runway, but when on
final approach they can't see anything.
approach for landing
Distances at night are deceptive, due to lack
of illumination and inability of the pilot to judge them by the usual
method of comparing the size of different objects.
At night, fly towards an airport light and
make a standard pattern, rather than attempting a straight-in approach.
The perception of distance can be dealt with by flying the downwind leg
until the touchdown point is half-way between the wing tip and tail. They
turn onto the base leg.
The only way to approach a runway in the
mountains at night, with complete safety, is to incorporate the "spot
method for landing" technique.
The flare and landing is accomplished in the
same manner as during the day. There may be a tendency to look too far
down the runway, causing the flare to be too high.
night flying tips
carry a workable flashlight (You can recognize the pilot who has
flown at night without a flashlight. He's the one that has two or
more flashlights in his bag).
Close one eye
when exposed to bright light.
eyes to view off-centre.
eyes if they become blurred.
attempt violent or abrupt manoeuvres at night.
the disappearance of ground lights or an area of glow around the
navigation lights. This indicates entering instrument
the deceptiveness of altitude and speed at night. A normal
approach looks steeper at night, creating an illusion of
judgment at night is less accurate than by day. A simple visual
assessment can lead to a premature descent.