Winter Cometh
by H. Dean Chamberlain
Reprinted with permission of FAA Aviation
News
As
you read this last issue of 2002, FAA Aviation News wants to
remind those of you who have not prepared yourselves and your aircraft
for winter flight ops, time is running out. For some, time has run
out. For those of you and your aircraft basking in the sunshine and
warm temperatures of the Sunbelt or the islands, please bear with us.
At the
beginning of this year, January 10, there was an interesting search
and rescue story that highlighted why each year we remind everyone
about preparing for cold weather operations. According to CNN's
datelined story from Purgatory, Colorado, 'A sightseeing plane pilot
survived two crashes in the snowy Colorado Rocky Mountains after his
plane crashed with two passengers aboard; he went to get help, and
returned in a rescue helicopter that also crashed. All passengers on
each flight survived.'
According to the news story, the two injured survivors of the Cessna
172 (C-172) spent a freezing night waiting for their pilot to return
with help. The pilot had walked six hours through snow until his cell
phone worked so he could call for help. Then while helping the U.S.
Air Force rescue helicopter find the C-172 crash site, the rescue
helicopter crashed. This was crash number two for the Cessna pilot in
two days. The Cessna had crashed on the ninth. The helicopter crashed
on the 10th.
As a
safety magazine, we are commenting on this story because it highlights
the importance of being prepared for winter survival, or in this case,
the risks of not being prepared. CNN reported neither passenger was
wearing winter clothing. One was wearing shorts. The aircraft did not
have survival gear or blankets onboard. The reported temperatures the
night of the Cessna crash were teens to low 20s. A member of the
sheriff's department was quoted as saying any time anyone survives a
plane crash, it's remarkable, but it's even more remarkable in the
Rocky Mountains in the winter.
Like
many accidents, the flight reportedly started out as a short
sightseeing flight. We are using this story to show that no matter
where you live and fly, even a short sightseeing flight can have
dangerous consequences.
FAA
Aviation News
has repeatedly said that pilots and passengers should dress to be able
to walk home from any flight. Since by definition, an accident is an
unplanned event, this means every flight should include the
possibility of a walk home. It may be a remote chance, but the chance
exists as this case proves.
Some
areas of the U.S., such as Alaska, have specific survival equipment
requirements. Most areas leave it up to the pilot to determine what,
if anything, to carry. Just like when driving your vehicle down an
isolated snow-covered country road late on a cold winter night, it is
better to wear your winter coat than to throw it in the back seat and
depend entirely on your vehicle's heater to keep you warm. The reason
is if you skid off the road and into a ditch injuring yourself, how
will you keep warm when the engine dies? What will you do until help
can find you? The same is true in an aircraft. If you can't reach your
survival gear or winter clothing because of injury or you are trapped
in your seat and can't reach the items, you are out of luck. As we
noted in our article on desert survival this summer, you need to keep
important survival items within reach. This is not to say you
shouldn't properly secure them. The last thing you want in a crash is
a loose object flying around the cabin.
One of
the best ways to avoid landing out in the boonies or on a remote
mountaintop is to make sure your aircraft is properly prepared for
winter. Your aircraft's operating manual lists those things you need
to do to prepare the aircraft for winter ops. From making sure the
proper weight oil is installed to checking the battery to checking the
fuel system for water'read potential ice cubes in your tanks and fuel
lines when the temperature goes below freezing'to checking your
control cables for proper tension to checking your oil cooler's cold
weather operating requirements, you have a lot to check before the
thermometer takes its annual nose dive. If you live in areas where the
temperature has already headed south for the winter, you should have
already completed your winter checklist. You did winterize your
aircraft? If you have any questions about what has to be done to
prepare your aircraft for cold weather ops, your first stop should be
your pilot operating handbook. Your aircraft service manual also
outlines the steps to take. If you have more questions, you should ask
the maintenance professional who works on your aircraft. FAA also
publishes information on winter procedures. An Internet web search can
provide a wealth of information. Your local Flight Standards District
Office's Safety Program Manager is also a valuable resource.
Obviously, if your aircraft is relatively new, your aircraft
manufacturer is your best resource. If you have an older aircraft, the
type club for your specific brand and model of aircraft is another
important resource. If you don't know how to contact your respective
type club, most clubs, such as the Cessna and Piper clubs, are listed
on the Internet. Another important resource is your local Experimental
Aircraft Association chapter. Most smaller airport fixed-based
operators have some type of bulletin board with local chapter
information. If not, again check the web.
FROST AND ICE
It goes
without saying that frost and ice on your aircraft can ruin your whole
day. You should never take off with frost on your wings. Aircraft
wings don't fly well with frost on them. The same is true of ice. If
your aircraft is not certificated for flight in known icing
conditions, it is important to stay out of such conditions. Any time
there is visible moisture and below freezing conditions, there is the
possibility of icing if you penetrate the moisture. Although frost can
reduce or destroy lift, ice's danger is twofold. Ice build up not only
can reduce or destroy lift, but it also adds weight. Combined, both
can make it difficult or impossible to maintain altitude or continued
flight in aircraft not approved for such operations. Even those
aircraft approved for flight in known icing conditions have
limitations. In severe icing conditions, ice can build up so fast that
the aircraft's deicing or anti-icing systems can't keep up with the
buildup.
This is
why all pilots should have an escape plan if they inadvertently start
to pick up ice or the build up is greater than their aircraft can
safely handle. Whether it knows the altitude of warmer air or where
they can fly out of the icing conditions, pilots should have a plan.
Part of that plan knows when to ask air traffic control (ATC) for
help. Declaring an emergency is always an option. In reviewing
accident reports, it is always better to ask ATC for help before the
situation becomes critical, than it is to wait until it is beyond
ATC's ability to help. It goes without saying; you need to know how
and when to use your aircraft's anti-icing and deicing systems. In
case of ice buildup en route, follow your aircraft's operating
manual's recommendations about landing speeds. You may want to carry
extra speed during landing if the field length permits.
ICING IS NOT THE ONLY RISK FACTOR
IN WINTER OPS
Not
only is it important to make sure your aircraft is prepared to operate
in winter flight conditions, but a recent National Transportation
Safety Board report noted pilots flying in mountainous terrain before
official sundown may experience night conditions in the valleys
because of terrain masking of the sun. This condition highlights the
importance of being night current when flying near sundown in
mountainous areas. Although sun masking is not a problem in the
flatlands of the Midwest, pilots in those areas need to be just as
night current because of the limited amount of daylight hours during
the winter months.
Nighttime can be a very enjoyable time to fly for those who are
prepared. Current charts, airport data including airport operating
hours, knowledge of minimum altitudes, and a spare flashlight are a
few of the important tools to have onboard for a winter night flight.
Instrument pilots who are current and proficient have an inherent
safety advantage when flying at night if they are operating on an IFR
flight plan. Their charts provide them safe operating altitudes and
guidance as long as they follow the published procedures.
COLD WEATHER PREFLIGHT
In
addition to limited hours of daylight, another human factor element
you need to think about is how are you going to do a thorough aircraft
preflight. For those pilots with heated hangars this is not as
critical an element, but for those pilots whose aircraft are tied-down
outside, it takes a disciplined pilot to do a complete and thorough
preflight when the temperature is below freezing and the wind and snow
are blowing. The urge to kick the tires and jump into the aircraft
must be controlled. Add in some darkness and the urge to just fire up
the engine can become overwhelming.
Adding
to this risk of trying to get out of the cold is trying to avoid a
complete aircraft preheating which includes the engine and cockpit
area. Failure to properly preheat an aircraft can result in additional
wear on the engine, a chance to rundown the battery, and cockpit
instruments not operating properly. In addition, some pilots may try
to reduce their cold exposure by taking shortcuts when preflighting
their aircraft. They may even decide not to properly de-ice their
aircraft or remove all of the frost, snow, or ice contamination on it.
Although heated hangars are great in the winter, remember that moving
a warm aircraft out of a heated hangar in near or below freezing
conditions can cause any falling snow to melt which later might freeze
if the temperature is below freezing at altitude. Controls may freeze
or wheels may freeze up in the wheel wells. The same can happen if
rain, water, or slush is encountered on the ramp or runway before
takeoff in near freezing conditions.
The
following are some things that pilots should be aware of when
preflighting their aircraft in freezing temperatures. Pitot heat
should be checked before every flight. Then there is the chance water
may have frozen at some point in the aircraft's pitot system. You
should have a plan in case the pitot becomes blocked. Although
aircraft will fly with a blocked pitot system, pilots have had
accidents when a blocked pitot system caused a loss of indicated
airspeed. The old formula of power plus attitude equals performance
will keep an aircraft flying when indicated airspeed is lost. The loss
of airspeed readout is no reason to have an accident. In addition to
possible pitot system blockage, pilots should check for possible
induction air cleaner blockage. The air cleaner may have collected
some moisture, which could freeze, and block the system. Carburetor
heat, if applicable, and windshield defrost should be checked for
proper operation. For those aircraft with embedded electrical wiring
window heating, you need to follow the operating instructions to avoid
damaging the window. As the temperature drops, you may want to give
your gyro instruments extra time to come up to speed. This is why it
is helpful to preheat the cockpit in addition to the engine. Finally,
if your aircraft has liquid crystal instruments, you need to follow
the manufacturer's instructions to ensure proper cold weather
operation.
WINTER CROSS COUNTRY
If you
are one of those pilots who fly between cold to hot or hot to cold
areas of the country, you need to pay special attention to your
aircraft. If you are planning on flying say from North Dakota to
Arizona or Maine to Florida in January and you have winterized your
aircraft, you need to remember to review your operating conditions
before your flight to make sure your aircraft will not let you down.
If you have installed a winterization kit, you may have to remove it.
If you have an oil cooler baffle installed, remember to remove it to
keep your oil temperature within the approved range. If you are flying
from a warm area to a cold are you may have to install a winterization
kit at some point. You may have to change oil depending upon the
temperature operating range of the oil you have installed. These are
only some of the things to consider when making a long cross-country
trip out of your local flight area. You're departure, en route, and
your destination conditions all need to be considered to make sure
your aircraft is operated within its limitations.
RECAPPING
Quickly
recapping, you and your aircraft need to be prepared for winter flight
operations if you live and operate in snow country. That means
winterizing your aircraft, knowing how to properly start the aircraft
in low temperatures, and updating your flying skills.
Although we could continue outlining things to do, we want to end this
short article by reminding everyone of the need to be careful when
landing on snow-covered runways or where braking is suspect. More than
one aircraft has ended up off the runway when the aircraft hit a patch
of ice while landing. Recently, in a discussion about how airports
report runway braking, it was brought out how different types of
aircraft and braking systems can handle different runway conditions.
Just as in reporting turbulence, what may be light turbulence to one
type aircraft may be moderate or severe to a smaller aircraft. The
same is true of reported runway conditions. You need to be able to
translate the reported conditions to your aircraft and its braking
system. You need to have a plan in mind in case you can't stop on the
runway. Knowing when a situation is starting to get out of control is
the first steps in initiating a successful go around. The old adage,
when in doubt goes around, applies.
Finally, if you get stopped on a snow-covered runway, be careful
taxiing to the ramp. More than one aircraft has missed a turnoff and
ended up in the grass or hit a snow-covered light fixture or snow bank
along a plowed runway or taxiway. Another danger of snow-covered
runways and taxiways is the fact snow can cover critical markings. In
one case, a pilot was involved in a runway incursion incident because
a hold-short line was covered by snow. The flight's not over until the
aircraft is secured and your flight plan is closed. You did file a
flight plan? An activated flight plan is your best friend in case you
need help. Flight plans are free: Please use them.
It is a long winter. Have
fun and fly safely.
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