flying at night
Night Flight:
The phenomenon of night poses a risk for all pilots regardless of
experience but the inexperienced pilot is especially at risk. 72% of our
flying information comes through the eye and the eye is easily fooled at
night. The darker the night, the absence of a horizon and lack of recency
are danger signals. The inexperienced pilot has from 20 seconds to three
minutes before losing control after the onset of spatial disorientation.
Once the eye lacks required information, the brain seeks information from
the inner ear sensors and the proprioceptive system of our flesh and
bones. When there is nothing for the eye to focus on it defaults to about
four feet. We will not see at a distance unless the eye is made to look
into the distance. It is possible for an aircraft to turn so slowly that
the body senses will not recognize it.
Science now has an electronic jacket that will give the body sensory
perceptions arising from our aircraft instruments. An enhanced ground
proximity warning system (EGPWS) is coming that gives vocal warnings of
what is happening and what to do about it.
Night flying has a higher accident rate than identically day flying.
Airport weather reports are valid for five circular miles around an
airport. Everything between airports will be different for better or
worse. A PIREP is worth a dozen forecasts, especially at night. Since
night clouds can be invisible, be prepared to go on instruments and make a
180. When your flight has made the 180 your only option your risk factor
goes straight up.
Always have aircraft and flight kit prepared for unplanned night flight.
Night causes usual visual flight aids to become nonexistent. Night visual
and sensory illusions are unique to the conditions. Do not look directly
toward the area where you expect to see best. Look slightly to one side or
the other. This visual outlook applies to the landing flare as well as
every other situation. The special skills of night flying can only be
acquired and maintained by frequent night flights.
For night flying you must evaluate the relative risks of such a flight A planned
night flight is far less likely to make its planned departure time and
arrival time. If schedule is going to be important, don't fly at night.
Change either the flight or the schedule.
Failure to use oxygen above 5000' at night means that you accept the loss
of 5% of your remaining night vision for every additional 1000 feet of
altitude. An additional risk exists if the pilot fails to get an adequate
weather briefing especially the one related to dew point - temperature
spread. Reduce your night range so that you can refuel before dark and fly
to an airport with 24-hour fuelling. Two C-172s on a collusion course
without anything other than navigation lights will fly over five miles in
less than a minute, use your landing light.
Being lost at night is more critical than in the daytime just as will be
an engine failure. Emergency landing situations at night can be improved
to full-moon lighting conditions with the purchase of a night-vision
monocular for about $200. Ten-times as many accidents occurring on dark
nights as with moon light and nearly 30% of the fatalities and an
additional 15% of the non-fatal accidents occurring at night where not
quite 5% of the flying takes place the $200 spent for a night vision
monocular seems to be a reasonable purchase for the pilot who chooses to
fly at night.
19% of total fatale accidents occur at night because of power related
forced landings. l4% occur during the day in similar power related fatal
accidents. The disparity in these figures (they lie) is that only 4% of
flying is at night. A high proportion of the fatal accidents were in twins
while none were homebuilts or warbirds. Yes, a higher proportion of fatal
accidents do occur at night. Evidence shows that in a well-maintained
engine and aircraft the risk to life due to engine failure is slight.
Night flight checklist
The FAA in its wisdom or lack of it depending on perspective has
three different definitions of when it is night. FAR Part 91 says that
night is from sunset to sunrise as far as the operation of position
lights. Night, according to FAR Part 61 is from one hour after sunset
until one hour before sunrise for purposes of night landing currency for
carrying passengers. The official definition is in FAR 1.1.
Go or No-Go Decision
Media weather
Weather broadcasts
PATWAS (Pilot's automatic telephone weather answering service)
TIBS (Telephone information briefing service)
No!
Saying, "No, we won't go." makes you a PIC. If you really know what you
are doing you will know when to say "No!" The strongest voice in
opposition to "No!" is time. Know your minimums and hold to them.
Flying at Night Is Not
Just like Flying in Daytime ...
The hazards of night flying are directly related to the physiological
limitations of the human body not the aircraft. Humans do not perform well
at night. Night flying will be different. Night flight is more stressful
than day flying and very near to IFR flight without the required training.
It should be. A moderate amount of stress will improve performance,
keep the pilot awake and motivated. However, subtle events occur at
night that would be easily detectable in daylight. The solo pilot at night
is at greater risk than when flying with an attentive passenger. Night
flight requires the pilot be very familiar with the area and have special
knowledge that can be acquired only through experience.
Night flight is so completely different from day that it requires careful
introduction. Any pilot deficiencies become magnified at night. The night
horizon is less visible and more indistinct. Night flight is semi-IFR with
considerable reliance on the instruments. Clouds and terrain are from
difficult to impossible to see. On monocles nights, the objects seen are
those which are illuminated enough to stand out. There can be a gradual
loss of visual clues when flying into darker terrain. This leads to
disorientation and loss of control.
Night flight adds to the risk of single-engine flying. Emergency options
are reduced. The new five-mile VFR minimums increase the impact of
weather. Mandated preparation for the flight such as lights and
flashlights make a difference. You will be much more able to cope if you
maintain radio contact with ATC and have a readily available frequency
list. I avoid night training flights that have less than 1/4 moon. Common
mistake is flying when combination of pilot, conditions, aircraft, and
preparation are not up to making the flight. AIM recommends supplemental
oxygen at 5000' at night and at 10,000' daytime.
Flying a consistent profile is essential to safe night VFR. Be so aware
that you do not descend below 1500' AGL until you are within engine out
distance of the destination. Plan to make a standard 45 entry so that you
will reach pattern altitude when turning downwind. If ATC gives you a
straight in maintain pattern altitude until you are on two mile final. Fly
a VASI or PAPI if available. If you know your ground speed, multiply it by
five to get a 3-degree descent path.
In 1991 the night requirements for uncontrolled airspace were essentially
raised to controlled airspace requirements. Not having the instruments
easily visible/readable is bothersome. A 30-degree unobserved turn can
cause complete disorientation. The absence of a horizon can cause loss of
control. Both situational and geographic disorientation is more likely.
Our ability to make a truthful prediction of our next night flight is of
extreme value. When night flying pilots flounder in hesitancy and
indecision, we find that the successful outcome of any flight depends more
on pilot confidence in his competence. Confidence is a by-product of
competence.
Every night flight or breath for that matter involves a risk on some
level. What we do can be evaluated and delineated as to the mathematical
risk factor it presents to us. Every night flight decision we make holds
consequences. Not making decisions also holds consequences. The ideal
would be that we be able to have the foresight to see living and night
flying in terms of future consequences. We can't, so we do what we can to
face the risks.
Fact is that we do have this predictive capability if we but know HOW to
use it. The chances we take in life can be measured and controlled by the
way we handle future events. Mathematicians and thinkers since 1654 have
provided the probability theory needed to place a degree of certainty into
our uncertainty, risk taking and decision making. A pilot must accept the
presence of risk and the existence of fear. Both are present and accepted
as part of the process. Being afraid makes you more careful. As time fades
memory, we are apt to once again approach the risk fear situation but this
time you will probably have more awareness and respect for the possible
negative outcomes. Your fears are instance policies
Night flight risk analysis begins with finding causes that are influenced
by indirect and subtle correlative events or conditions. The relationships
are usually not clearly defined but more often summarized as being
present. Whenever a kind of relationship does exist we have a correlation.
If night accidents are caused by darkness, then primary correlative
elements would be amount of natural and man created light. Additional
correlative elements of area familiarity, experience, maintenance,
equipment, weather and interior lighting come immediately to mind.
The FAA, NTSB, AOPA, and insurance companies have gathered and maintained
the data base of night flying statistics compared to day flying
statistics. The data, through statistical inference points to causality.
Modern computers can crunch the numbers to find future probability.
Without this gathering of data there would be no prediction of
probability. Enough samples of night flying accidents with selected
correlative elements gives us probability.
The ability to make a prediction of accident probability for a given night
flight resulting in an accident results in a number. The number is a
percentage that gives the probability of an accident occurring. With
sufficient data transposed into percentages a person is able to compare,
decide, and fly at night in given conditions with some assurance of a
non-accident flight. It is a gamble on the odds of event probability. A
pilots decision for making any flight, day or night, has to be based upon
this theory of decision making because there is no certainty as to what
will happen. This is a process that every pilot partakes from for every
flight, night or otherwise.
We use risk analysis to evaluate the consequences of starting the engine,
taking off, flight altitude, direction, and landing. To do otherwise is to
be oblivious of probability as it can and does affect all our lives. Don't
say that you don't gamble, take chances, and challenge probability. You do
and it makes your life more worth living because certainty will destroy
incentive, interest and curiosity.
40% of all night takeoff accidents have non-instrument pilots. Of all
night accidents the darkness of the night was listed as a factor in 54%.
26% were judged to be caused by spatial disorientation. Most of the
takeoff accidents occurred with in 3 miles and one minute of takeoff.
More often than not the pilot was unaware of his unusual attitude. The
darker the night the more important is instrument flight capability.
Hundreds of pilots before you have made the risk decision in favour of
taking night flight. In the proper moonlight conditions you can see well
enough to see clouds, water, some terrain and many lighted areas. A flight
over familiar areas at night is a thing of beauty. Other aircraft can be
detected far beyond daytime sighting distances. Night landings are acts of
faith. You must believe that the lighting and surface delineate the
airport and a safe place to touch the earth. Oddly, taxiing at night is a
very difficult process. Many aircraft lights do not light your way. Flying
at night is like the risks you take with a beautiful woman. You could wind
up married (buried).
Physiology of Night
Read up on the physiology of night vision to better understand the
operation of the eye. Over age 40, fatigue, and smoking affect visual
acuity and adaptation to darkness. Do not look directly at an object at
night because the optic nerve location may not let you see it. The
decrease in oxygen above 4000' decreases visual efficiency. Air Force
requires full oxygen from the surface at night. The light smoker is
physiologically at 3000' before he gets into the plane. Above 8000' at
night it is a good idea to have oxygen. Since we don't see as well as
might be desired at night we must compensate using experience (brains) and
technology.
The human eye performs poorly at night. Fatigue has greater influence on
pilot skills at night. The retina is the first and fastest part of the
body to react to reduction of blood oxygen. Cigarette smokers start out
with an immediate night vision problem. Night vision can be improved by
the use of oxygen. Night flying errors happen because of human lack of
capability. Night vision is the key limiting factor. Without surface
lights, it is hard to know your altitude above the ground, with surface
lights it is difficult to locate the airport beacon.
Most night accidents occur on 'dark night' flights. Fatigue makes all of
the safety factors involved to be more likely misjudged. Raise you
personal safety parameters at night and raise them even more when
fatigued. Skilful night flying is fragile, unused night flying skills
must be polished regularly or they will be lost quickly. The eye is much
like a video camera. A view is focused on the retina, converted
electrically to data sent to the brain. Rods and cones make the visual to
electrical conversion. Cones, near the focal centre give colours,
brightness and sharpness when light is good. Rods are the night-vision
part of seeing. The peripheral region of the retina is rod territory. Rods
make it so we can see at night but not in colour. Complete night
adaptation of the eye to darkness can take over 30 minutes and be
destroyed in seconds.
The human eye is a dual system devoted to day vision or night vision. The
duality has inherited abilities that vary with the individual. Some pilots
just see better, day or night. Some eyes have retinal structure and nerve
elements that are visually more efficient. Pigment and other factors such
as pupil size allow eyes to respond to weak stimulus. Age affects the
pupil's ability to change size. The wider the pupil the better the night
vision. A pilot's ability to adjust to darkness deteriorates with age.
The rods and cones adapt to night conditions. The cones are centred in the
eye but are slow to adapt and then only by a factor of x 100. Rods spread
to the sides in the back of the eye. They are more sensitive at night by a
factor of x 100,000. Rods take 30 minutes to recover from a bright light
shock.
There is an oval shaped region of the retina known as the blind spot. It
cannot see light.
Binocular vision compensates for this in daytime.
At night we often are unable to see objects if we look directly at them.
To see at night we cannot look directly at what we want to see.
Your central vision is inoperative at night.
Looking off centre at night uses peripheral vision.
Peripheral vision is 100,000 times more sensitive than central vision at
night.
Your eyes can be adapted to night vision by wearing red glasses,
patching one eye and using dimmed lighting.
No matter how well you do this one flash of a strobe taxiing out
destroys it all.
It the lighted airports of today
it might be easier to work in a lighted cockpit.
90% of our orientation is visual even in the cockpit.
NASA has proven that there is less oxygen at night than during the day.
The eye is quite susceptible to oxygen deficiency.
Vision at night at 9000' gives the visual acuity that you would have at
15000' during the day.
Your visual adaptability to light/darkness is reduced 50% every eleven
years of your life. Experience and frequency of night flight is the best
compensation for this loss. Any bright light effectively reduces night
vision. You might try protecting one eye from light until airborne. Try
wearing sunglasses at dusk.
The use of colours other than red in the cockpit has become more common in
the 1990's. Light-emitting diodes are more efficient than other systems
and will be in all cockpits of the future. Blue lighting such as is common
in military aircraft requires much more lighting than white lighting.
Vitamin A is a vital element for night vision and adaptation. Vitamin A
deficiency will make a significant difference in night vision. However
excessive intake of Vitamin A will not give an apparent improvement.
Ample oxygen is necessary for adequate night vision more so than day
vision. Above 4000 feet supplemental oxygen will improve night vision.
There will be an initial decrease of 5% in night vision and the deficiency
is accumulative over time. At 8000 feet the initial effect is about 15%
and will become worse with time. The most dangerous aspect of this is that
the pilot has no way of knowing that he is not seeing as well.
The wearing of sunglasses during the day is one way to improve your night
vision. Neutral gray glasses seem best in their ability to absorb
ultraviolet light. At night, red lenses will absorb blue light and aid
dark adaptation. Limit your use of bright lights at night since even a
momentary flash can destroy your night vision.
Should blur interfere with the things you see at night, it may be
indicative of night myopia. Squinting will help some or the use of
glasses. If the eye is unable to focus on anything at a distance at night
it may be having space myopia. Keeping the eyes moving can help limit
these effects that are made worse by staring.
Objects are harder to see at night just because they are less well defined
around the edges. This makes things appear farther away than they actually
are. The requirement for glasses at night is much greater than during
daylight.
Night Sight Skills
The ability to judge distances and heights at night is difficult
at night. The absence of haze or its presence can cause illusions at
night. Lights will vary in intensity and cause illusion effects. A
misidentified light source can cause total confusion. A single light gives
no altitude information. Multiple lights may be in different geometric
visual planes. Freeways become visible while country roads disappear.
Aircraft and lighted towers become visible for miles. Airports have
beacons. The most common illusion is a narrow runway that appears to be
longer than it is. the narrow runway may make you think that you are too
high. Have a set procedure; allow an extra wide downwind at night. Know
the length of your destination runway. Required FAR knowledge on all
flights! All illusions are made worse at night.
Preparation for night flight must be more intensive and comprehensive.
Make your initial night flight preflight during the day. Check all the
lights and carry a spare bulb. Visual checkpoints are much closer. Fuel
reserves are doubled. Charts are marked with black felt tip pens.
Frequencies are written large. Terrain altitudes are noted and crossing
extra altitude added. Weather makes a big difference. At night you can't
see weather unless there is a moon. We get very used to seeing weather
change during the day. Weather changes much the same way at night but
quicker. You must expect weather changes at night to occur suddenly simply
because we cannot see the changes occurring as we can in daytime. VFR to
IFR at night by non-IFR pilots is usually fatale. 100 to 200 hour pilots
have most such accidents.
One flashlight is not enough. One big flashlight for preflight, a small
one for reading sectional etc., and one backup. Night flying is safest
when there are no clouds, a good dewpoint-spread and minimum winds. Don't
fly at night into areas where you are not very familiar in daylight. Have
the legally required landings and carry another more experienced pilot
(instructor) for cheap insurance.
Night X-Country
Preparation
Make an an honest assessment of skill and limitations. Routes,
frequencies, weather, moon phase, airport information, terrain heights,
FAR's related to night flight, night flight checklist
PLANNING:
1. Take a blindfold test of
the cockpit 2. Older pilots need more light 3. Limit night flying to familiar aircraft. 4. An organized cockpit,
5. Charts in order and folded for use, no red lines but well marked 6. Closer checkpoints selected by time between and for night visibility 7. Obstructions marked, ground routes/terrain studied 8. Higher than normal altitude for terrain clearance 9. Plan a what if...non-electronic flight possibility 10. Airport, city-lights proximity route with VASI, PAPI runways 11. Minute VFR fuel reserve required 12. Reduce range 1/3 keep track of wind direction and speeds 13. No straight-in to strange airport, make high/steep approach 14. Phone day before to an unfamiliar field for suggestions 15. Extra careful preflight checking lights and spare fuse 16. Always plan to get fuel before FBO's close for the day 17. Weather notes on temperature/dew point spread
PRE-FLIGHT for
Night Flight
Have current sectional and
area charts, flashlights, pens, radio backup? Check all lighting. 1. Night reference to instruments takes longer than in day light. 2. Look outside more than inside 3. Set all lights at lowest intensity that can be seen without effort. 4. White lights increase mental alertness 5. Clean windows 6. Use landing light when near airports. 7. Limit landing light use on ground due to over-heating of bulbs. 8. Run-up creep is more likely to be undetected at night 9. Use caution in proportion to darkness 10. Lighting should be limited to preserve night vision 11. Practice taxiing using navigational lights 12. Tower can use light-gun to light centre line of taxiway 13. Know where you are at all times and know the nearest landing spot. 14. If confused get assistance---CCCC 15. Moonlit waters and freeways make good checkpoints 16. Cloudy, moonless, windy nights are most difficult 17. CAVU weather with full moon is best 18. Recommend 1/4 moon as minimum unless IFR capable 19. Keep altitude 'insurance' in force at all times. Know your terrain. 20. Check heading indicator/compass at checkpoints 21. Be prepared to go on instruments and make 180 if you fly unexpectedly
into a cloud. Major cause of night flying accidents. 22. Review causes of vertigo and disorientation 23. Try not to pass a checkpoint without being oriented to next one 24. Report your positions with extreme accuracy 25. Night flight requires your highest level of precision and skill. 26. Extreme levels of flying skill may be required all at once. 27. Reference the A/FD to get frequency and procedure for turning on
airport lights. 28. Black hole takeoff and landing occurs in regions of few lights such
as toward the ocean or a mountain. You must be .....instrument competent. 29. VASI or PAPI runways help you to avoid night landing illusions.
Night Flying
Be IFR rated Trust your instruments Coordinate your turns Hold your head still Don't fly alone Lower lighting Have flashlights Use oxygen Use electronic aids Fly the airport pattern Eat right
Night and Age
Colours are not as clear and sharp More light is required Recognition takes longer Disabilities exist Pupil size is smaller Focus range and speed decreases Visual accommodation may take several seconds
Night Taxiing
Night taxiing is more difficult than any taxiing other than
zero-zero conditions. Night conditions are also difficult for the
controller. the controller may not know where your are any more than you
do. Be as specific as your can as to your last known location, your
compass heading (you may not have set your HI) and the colour of the line
over your nose. At night, don't do anything except taxi and keep track of
your position. The more experienced you are the more willing you seem to
be to admit a problem of ignorance and a need for help. When in doubt,
stop.
Many aircraft have inadequate taxi lights and even lighted airports have
unlighted areas. A tower signal light can be used to show the centre
taxi line. As age enters the picture, night vision fails. When
taxiing use as much lighting as you can and get any available assistance
from ATC. Being totally lost on your home airport is not uncommon.
When you need
help, get it.
Night ground operations are more difficult. You may be able to follow the
taxiway with a nose light while a wing-tip light makes it difficult to see
the yellow line. Be considerate of other pilots and don't use strobes
while on the ground daytime and especially at night.
Night Takeoff
Taking off into dark terrain may give an illusion that causes the
pilot to make a bank or shallow descent. Dark-terrain takeoffs should be
made on instruments. Night takeoffs should rely heavily on instruments
until altitude is sufficient to allow for any monetary disorientation that
is likely to occur using visual reference.
Factors:
Weather
If you are cautious during the day, be doubly cautious at night.
If your strobes sparkle it indicates rain.
Visual illusions
Lack of lighting over final approach gives too high illusion.
Instrument competence
Greater attention to instruments at night.
Select altitude and airspeed and keep it
Abrupt power reduction gives nose down illusion. (somatogravic)
Workload
Biological clock problem
Be rested
If solo use ATC services
Anxiety
Experience and training
Don't activate lighting too early while taxiing out for takeoff or too
early when arriving for landing.
Very dangerous to takeoff into total darkness like toward the ocean--you
are IFR,
Check heading indicator to correspond to runway prior to takeoff.
Make no turns until at safe altitude.
Remember scattered lights on a mountain can be confused with stars if
there is no horizon.
Night landings
1. Use your landing light.
2. Avoid turns when cockpit workload is high.
3. Don't hesitate to ask tower to turn up lights
4. Pre-select an early go-around point and use it.
5. Use a slightly longer/steeper final than normal.
6. Know how to get lights at an uncontrolled field.
7. Flare level and don't try for full stall landing.
8. Maintain constant airspeed on final with power on.
9. Remember distances can be very deceiving at night.
10. Practice landings with and without landing lights.
11. Practice landings with and without landing lights.
12. Undershooting at night is greatest cause of accidents.
13. Avoid long shallow approaches. The steeper the better.
14. Down slope lights cause high approaches and long landings.
15. Up slope lights cause low approaches and landing short of runway.
16. If flight takes place at night with 25% of the accidents--either fly a
lot or NOT.
17.If you are insecure flying at night, consider limiting bank angles to
half of normal.
18. Straight in approaches are most dangerous unless VASI or glide slope
available, make high steep approach.
19. If moisture reflects from landing light beam do not use for landing
since it usually causes you to flare high.
You must know critical information (heights of terrain), that which can be
seen Vs unseen at night, (freeways Vs country roads) situational
awareness becomes vital, willingness and ability to communicate to ATC.
and knowing the performance parameters of the aircraft cold (without
interior lighting) is beyond the just "nice to know" requirements of
daytime flight.
The descent to the airport should be planned well before the actual
occurrence. Do what it takes to raise your level of mental alertness. The
safe performance of night landings depends on your ability to control
approach speed and altitude. If your daytime landing procedures are based
upon a stabilized approach the transfer to night landings will be easier.
The stabilized approach gives you a reference from which to evaluate night
landing illusions. Your depth perception, visual cues, and runway
perspective will change at night. The desire to remain high and fast can
overcome your training. A high fast landing at night will be hard long and
dangerous. Like day landings a good night landing begins with a good
approach but it is not exactly the same. Avoid excess airspeed, use your
instruments to confirm visual impressions, especially the altimeter and
airspeed indicator. Set your configuration of power, flaps, and airspeed
as though doing a soft field landing.
Once you become aware of the many illusions that often occur at night. You
will see the advantage of flying a pre-selected approach pattern. Runway
lighting gives you an impression of runway area. There is an illusion as
to the runway length-to-width ratio. The vertical-position illusion occurs
when there is no visible horizon. It makes lights and visible objects to
appear higher than they actually are. The false-horizon illusion makes
lights and stars appear to blend so that you cannot be certain as to where
the horizon is. The foreground-occlusion illusion occurs when something
ahead makes a light disappear. Climb immediately.
Keep power on during a night landing. The terrain cues needed for flight
path correction are meager and undetectable at night. Look at the lights
toward the far end of the runway. When these lights begin to flatten out
you should enter your flare. Do not try to make a full stall landing. Your
visual ability to determine altitude at night is seriously degraded. Make
your flare using the runway lights at the far end of the runway. raise the
nose until they are covered, but no more. Hold some power on as the plane
gradually descends. You don't want to hit the nose wheel first but a
relatively flat landing at night is acceptable.
You need to be an active night flyer if you expect to make consistently
good night landings. You need to be doing at least 1/4 of your flying
at night to retain proficiency. With experience a pilot can become
consciously aware of the visual cues that are available and use them to
improve night landing accuracy.
Likely faults by those whose proficiencies are due to lack of practice
will be:
1. Approach speed too fast due to poor airspeed control.
2. Unable to detect/correct wind drift
3. Hard touchdown due to over-reactions during flare.
4. Likely to be below pattern altitude
Night Flying
The factors that kill both
good and poor pilots are both unpredictable and impartial. There are risks
in everything
we do. Flying has several added dimensions to these risks. The worst
flying risk is the needless risk. The needles risk is most likely to occur
when you are 'hurried' to do something.
The differences
between a prepared departure and an unprepared departure can be measures
in time. Pilots must learn not to chase minutes by hurrying, because your
limits of experience are being exceeded. If this should happen to you,
speak up, slow down and join those pilots who stress being good over being
lucky.
Night Lights
The rotating beacons all carry vital information:
Civil land: alternating white and green
Beacon operates daytime when field below VFR minimums.
Military land: two quick white flashes and a green
Heliports: rapid flashes of green, white, or yellow
Lighted water: alternating white and yellow
Uncontrolled Airport
Pilot controlled on CTAF frequency:
Low-intensity takes three clicks of mike switch
Medium-intensity takes five clicks.
High-intensity takes seven clicks.
VASI (visual approach slope indicator Have two for G.A. aircraft or three bars for 747 types. "Red over White, you're all right." Three bar VASIs will have two red over white for G.A. aircraft.
PAPI has four lights in a row on left side of runway On glide path gives two reds and two whites High gives three or four white Low gives three or four red
Night Illusions
Try some night airwork without cockpit lights. It will make you
listen more closely to the sounds of the aircraft. Runway and approach
light illusions will always be a problem if you are in an unfamiliar area.
For this reason it is always desirable to make a daylight familiarization
flight to an airport before a first time night arrival. If there is no
VASI or VAPI for vertical guidance if you get too low the runway lights
will begin to disappear.
A steep approach is always better at night. If there is a strong crosswind
and you are crabbing to the runway instead of slipping you will get the
illusion of being inverted. If the airport is well lighted in a
surrounding dark area you will have an illusion of being higher than you
actually are. Again a steep approach has much advantage. Rain on the
windshield will give the illusion of being higher than you are. An arrival
at an airport with and approach lighting system (ALS) tends to be lower
and at a shallower angle than otherwise. If you are low and pitch the nose
up as a correction or through the use of flaps, the illusion will indicate
that you are rising. Any reduction of power will cause you to land short.
At night, banking into or away from a line of lights will give the
illusion that a dive or a climb is occurring. The same dive or climb
illusion can happen by a change in aircraft pitch occurs while flying
toward a light. Lights that appear dim, as seen through haze, will be
reported as more distant than they are.
Pilots unconsciously make extensive use of their peripheral vision. Level
flight, banks, climbs, and descents all rely 80% on peripheral vision.
(See downwind turns) At low levels our peripheral vision gives us a sense
of speed. Over time we develop a peripheral sense as to what "normal"
low-level speeds are. Add a tailwind, low altitude, a bank to final
approach, and a peripheral sense of a "high" speed. We now have an
illusion causing a pilot response that says to pull back on the yoke to
reduce the speed. The pull merely makes the bank steeper and initiates a
low-level stall spin. Recovery is not possible.
A final approach over high terrain leading to the runway gives an illusion
of a low fast approach. An approach over terrain that makes the runway
seem like an aircraft carrier will give an illusion of too high and too
slow.
Night has its own illusions that are covered in the night flight lessons.
The distance of lights is greatly affected by the relative clearness and
haze existing. A region of no lights such as might exist off the end of a
runway toward the ocean can cause disorientation because of IFR illusions.
The best solution is to go on instruments until established inland at
altitude.
Black Hole Approaches
The black hole illusion is that you are too high on the approach.
The deceived pilot will descend into danger. The night focus of your eyes
is in the far distance. Again, the illusion is that you are overshooting
and you will again descend. Because of visual changes with age the older
you are the more likely you are to be fooled by the black hole illusion.
Glasses can be fitted to compensate for this difficulty.
1. Use charts
2. Use glide slope aids
3. Use published routes
4. Hang on to radar help
5. Never descend if uncertain
6. Know MSA for area
7. Have personal minimum altitude
8. Remain above VASI slope
VFR Night with IFR Help
Since the VFR pilot at night is subject to illusions that can lead
to controlled flight into terrain, the use of instrument approach
facilities can provide you with help in terrain avoidance. Pilots tend to
add speed when flying in insecure or uncertain situations. Most runway
overruns occur at night as do most IFR approach accidents. Night and low
visibility VFR approaches should be flown at appropriate airspeeds. Use
whatever IFR guidance is available.
No Light Landings at Night
(Emergency)
Landing in darkness techniques under emergency conditions. Select a
long runway. Use Localizer or ILS approach if available. Find a long
runway if available. Set power for slow descent with nose high, minimum
flaps, At 100' hold nose high but do not flare. Fly into the ground. This
method will work when flying into the sun and having difficulty seeing
runway.
General recommendation is not to go into an airport at night that you
haven't scoped out in the daytime.
Night Departures
Preflight before dark when possible.
Reference your charts, plates and AF/D before getting aboard.
Mark your chart and obstacles so that it can be seen at night.
Carry several different sized flashlights.
Use a night passenger-briefing card.
Locate all spare fuses and switches you might use at night.
Allow extra taxiing clearances to other aircraft at night.
Reset the timing clock for the runway lights.
Use only airspeed indicator for rotation speed. Night gives a speed
illusion.
At rotation focus on attitude indicator for pitch attitude.
Maintain runway heading or wind correction using heading indicator.
One degree of correction for every knot of crosswind component.
Every night flying pilot should have basic instrument flying skills.
Tests show that a non-instrument capable pilot will have control for
only 22 seconds.
Night Flight
Night flight compounds all the hazards that exist at all other
times.
The dearth of visual cues is what makes night flying different and more
dangerous.
Only regular practice at night will deliver the required proficiency in
flare and attitude selection for landing.
An unfamiliar airport at night compounds the difficulty and hazards.
Use of the AFD can warn of night landing hazards and obstacles.
Remain current on instruments because the same skills are required on
dark nights.
A flight that ends after dark will probably include fatigue as a
potential hazard.
Poor cockpit lighting in small aircraft increases the hazards of night
flight.
Set personal minimums such as 1/4 moon, light winds and long familiar
runways.
Common Night Accident Factors:
VFR into IMC
Descent below IFR minimums without airport in sight
CFIT on approach, takeoff or during go-around
CFIT into terrain or water
Improperly set navaids
Night greatly increases the hazard and likelihood of a weather related
accident.
66.7% of instrument approach accidents happen at night.
Only 2% of general aviation flying takes place at night.
11.5% of accidents occur at night
19.4% of accidents occur in weather at night
22.9% Occur on approach before reaching the runway.
46.7% Occur on an instrument approach at night.
Knowing Night From Day
Horizon:
Wherever one is located on or near
the Earth's surface, the Earth is perceived as essentially flat and,
therefore, as a plane. The sky resembles one-half of a sphere or dome
centred at the observer. If there are no visual obstructions, the apparent
intersection of the sky with the Earth's (plane) surface is the horizon,
which appears as a circle centred at the observer. For rise/set
computations, the observer's eye is considered to be on the surface of the
Earth, so that the horizon is geometrically exactly 90 degrees from the
local vertical direction.
Rise, Set:
During the course of a day the Earth rotates once on its axis
causing the phenomena of rising and setting. All celestial bodies, stars
and planets included, seem to appear in the sky at the horizon to the East
of any particular place, then to cross the sky and again disappear at the
horizon to the West. The most noticeable of these events, and the most
significant in regard to ordinary affairs, are the rising and setting of
the Sun and Moon. Because the Sun and Moon appear as circular disks and
not as points of light, a definition of rise or set must be very specific,
for not all of either body is seen to rise or set at once.
Twilight:
Before sunrise and again after sunset there are intervals of time,
twilight, during which there is natural light provided by the upper
atmosphere, which does receive direct sunlight and reflects part of it
toward the Earth's surface. Some outdoor activities may be conducted
without artificial illumination during these intervals, and it is useful
to have some means to set limits beyond which a certain activity should be
assisted by artificial lighting. The major determinants of the amount of
natural light during twilight are the state of the atmosphere generally
and local weather conditions in particular. Atmospheric conditions are
best determined at the actual time and place of events. Nevertheless, it
is possible to establish useful, though necessarily approximate, limits
applicable to large classes of activities by considering only the position
of the Sun below the local horizon. Reasonable and convenient definitions
have evolved.
Prepared for Night Emergency
Everything must be in reach
Both fresh and extra batteries
Flashlight (s)
Hand-helds GPS and Nav Com, phone
Know your systems
Know your fuse and breaker positions
Practice operation of cockpit while blindfolded
Have chemical light sticks within reach.
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