cold weather flying

Cold Engine Starts

Long-layoff Start

A cold start stresses the engine, the starter, and the battery. Engines and their accessories should be preheated below 20-degrees F. You control only the fuel/air mixture. Only atomized fuel can be made explosive. Cold fuel does not evaporate as well as warm fuel so more time is needed to create the starting mixture. Pre-oil if you can by gaining access to interior of engine through an accessory port. Otherwise, pull the plugs and spray an oil mist into cylinders. Now turn by hand to get oil pressure. After starting fly for at least an hour to make sure all moisture is burned out.

Turn the cold engine over a couple of times with the fuel off to clear the induction system. Next use the primer to put fuel into the induction system. This pump has jets that spray fuel into the intake manifold. Do not pump the throttle since pumping the throttle squirts a stream of gas upwards only to drip back down. This fuel can drip down and cause a engine fire if ignited by a backfire.

A cold start begins with two to three pumps of the primer. Lock the primer. Wait two to three minutes to allow the cold fuel to vaporize. As you begin to turn over the engine give a quick pump of the throttle.

If your engine does not have a throttle accelerator pump, you should leave the primer unlocked and fully extended ready to pump. Pull the throttle all the way out to 'choke' the engine. As soon as you turn over the engine give the primer pump a quick shot to enrich the mixture and lock it.

Pre Heat
You can use two 100 watt trouble lights inserted up through the cowl flap. This arrangement can give you > about a 40-degree temperature rise (use caution that the lights cannot break or damage any wiring or oil and fuel lines). Regardless of the system you use always pre-heat with an engine cowl blanket installed, this helps keep the heat around the engine."

Cold Weather Flying

Cold checklist
1. Have a new CO patch in the cockpit
2. Confirm with your mechanic that the muffler is o.k.
3. Winterize your engine and pre-heat your start (Drill out breather tube)
4. Provide for cockpit survival. with survival clothing
5. Check static and pitot for ice
6. Make sure quick-drains drain
7. Consider warming battery
8. Remove ALL ice, snow and frost.


Use a garbage bag filled with 10 or so gallons of hot water, knot the top and then wipe the top of the frost. This melts the frost and polishes it. As it re-freezes, the airfoil shape is maintained. Usually end up using 4 or 5 refills, and couple new bags, takes about 10 to 15 minutes.

Cold Flight Checklist

1. Only fly into improving weather
2. Know where to go to escape
3. Keep alternatives available
4. Runway lengths, surface and widths become critical


1. Because of the cold the cold weather pilot tends to abbreviate the preflight. Don't!
2. Look for fuel dye as indicative of fuel leaks.
3. Keeping the tanks full keeps out moisture.
4. Ice in fuel looks like floating dust.
5. Check engine cylinders and exhaust fittings for white stains.
6. Prime 50% more than normal when it's cold and 100% if really cold.
7. Use manufacturer's recommendations for cold weather operations
8. If heat baffles are used check their security. Is a baffle called for over the oil cooler?
9. Let engine warm up until oil thins out and pressure is normal.
10. Crankcase breather hose and system must be free of moisture.
11. Hoses, flexible tubing and seals become brittle in cold
12. Battery and charging system should be in good condition
13. A cold battery will be weakened unless fully charged
14. Cold oil will be more viscous (thick)
15. Control cables' lubricants will congeal. Check throttle and CH.
16. Don't use anything that works on an automobile to remove ice
17. Deicing fluids cause corrosion and leave unpleasant residue
18. Keep fuel tanks full and protect against contamination. Super-cooled fuel can create ice crystals and a rough engine. C.H. helps.
19. Preheat engine and cockpit prior to start when 10-degrees F. Heat under constant attendance and not directly on surfaces.
20. Store in heated hanger until just before departure
21. Don't let water get on hinges or movable parts.
22. Clean and dry pitot tubes, heater intake, carburetor intake, control surfaces and wheels.
23. Melt ice and remove all moisture, which may freeze again. Use hot water bottles or double-bagged plastic bags and plenty of dry towels
24. Check weep-holes under aircraft and drain interior moisture.
25. Confirm fuel selector is not frozen in one position.
26. CO detectors are recommended in addition to heater inspection


1. Thirty seconds of cranking = 50 hours flight time wear
2. Phone your destination just prior to departure
3. Plan to walk home.
4. Electrical loads will be heavier.
5. Don't set parking brakes, hot brakes will freeze solid.
6. Idle at higher rpm to keep plugs from fouling and oil hot
7. Normal engine temperatures are required to evaporate moisture in crankcase.
8. Change tanks more often so that maximum fuel is available. Fuel selector might freeze.
9. Flooded? Mixture out, throttle full. Crank 20 seconds.
10. Fuel/air more reluctant to ignite. Carburetor heat may be required for takeoff
11. Don't use throttle to over prime (two strokes maximum). Use engine primer, not throttle.
12. Most common cause of aircraft engine fires is prime with throttle
13. Prime only with primer. Over priming can be harmful.
14. If RPM rises when carburetor heat is applied it means that air filter is blocked
15. Don't try to force the warm-up
16. Gyros will need to warm up and speed up, too
17. Control cables will be tighter and stiff
18. Don't hand prop.
19. Keep wheels and brakes as dry as possible
20. May need to remove and dry plugs if engine fires only briefly.
21. Use radios only after electrical system has run a few minutes.
22. Braking may be poor to nil
23. Oil must be hot to perform properly. More viscous (thick) oil requires more cranking energy
24. Fix problems early before they become 'unfixable'.
25. Consider landing gear up
26. Use C. H. in icing range
27. Use C. H on approach and descent
28. Keep power up during descents and extend any drag that may be available. This will keep the engine warmer.
29. Taxi slowly, wheel bearings may be frozen, brakes may not hold.
30 Don't use flaps if tailplane icing is at all likely.
31. Don't use brakes until tires are on hard surface. Be prepared for ineffective braking. Touchdown areas of runways are more slippery.


1. Performance on runway may be less.
2. Reduce crosswind capability by 50% for snow and 75% for ice
3. On getting airframe ice, change altitude.
4. Climb through ice at high speed and shallow angle.
5. Descend through ice at lower speed but high rate of descent.
6. Climb above wet snow and freezing rain.
7. Reduced windshield transparency makes surfaces appear lower than they are. 5-degree slope errors are common.
8. If your planned altitude is within 4000' of z-level anticipate ice.
9. Plan an alternate route around convective weather.
10. Know the "times" as they apply to your flight. (fuel, battery, speed, alternate, etc)
11. Set power at cruise and don't change anything. Thus, if anything changes it means there is a change in power. Suspect carburettor or induction icing.


1. Ramp operations can cause 'black ice' problems for taxiing.
2. Weather systems move more quickly in winter. Fast-moving winter systems create turbulence and hazardous conditions.
3. Just because no ice is forecast doesn't mean there won't be any.
4. If you are flying in air only 10 degrees above z-level anticipate ice.
5. Freezing weather can make a survivable problem non-survivable
6. Where is the good weather?
7. Expect strong winds from the wrong direction
8. Snow changes the way things look
9. Light icing over a time is a serious problem
10. Ice usually exists under snow.
11. Moisture on runway that gets on aircraft may freeze when airborne.
12. Clouds dropping rain have less ice potential than do those without rain.
13. Top portions of clouds contain supercooled droplets.

Icing and PIREPs

Perhaps the reason there is a significant shortage of PIREPs is because not many pilots fly in the weather likely to make a PIREP important. PIREPs are especially good when they are about icing and turbulence but they are often just a snapshot and lose validity unless the pilot can fill in the whole picture. According to FAR 91.183 an encounter with unforecast icing requires a PIREP. The giving of a PIREP should be an independent communication and not given as a part of routine route information. The rate of ice accumulation is more important than the kind of ice. The AIM has an ice accumulation rate table which for accuracy must be judged by someone who flies only in ice.

Flight in Icing

All exterior sensors, pitot, static, and stall warning will be degraded as to sensing ability and accuracy. Antennae efficiency can be changed. Propeller unbalance is common. Fly at faster speeds than normal in climb, descent and especially landing. Most icing happens in visible moisture with temperature between zero and -14 C. Less than 10% of ice accidents occurred when ice was worse than forecast. No aircraft is certified to fly in moderate freezing rain. Any flight into forecast icing is considered by the FAA as a violation of FARs 91.9 and 91.13. by exceeding operating limitations and being careless and reckless.

As ice accumulates and lift decreases, the pilot must increase the angle of attack to retain lift for level flight. In this condition ice begins to accumulate beneath the wind and tail surfaces. You can't see ice below the wing in many aircraft. Any de-ice capability should be used only to escape the icing, not to continue the flight. You cannot afford to be casual while operating in ice. You need to be current in your skills related to unusual attitude recovery.

Carburettor ice is far more likely to occur and cause an accident than is airframe icing. 51% of icing accidents are caused by carburettor ice or induction system ice. The cause of this ice is the failure of the pilot to ANTICIPATE the possibility of ice by applying full carburettor heat and alternate air. The fixed pitch plane will develop a rough engine while the constant speed plane is going to show a drop in rpm. Under icing the C. H. will increase the roughness of the engine. Leave it on. Use alternate air if available.


0. The one-hundred-eighty turn is on record as having saved more lives than governmental inertia have killed.
1. Visible rain at below freezing temperatures
2. Splashing or splattering rain drops at below freezing temperatures
3. As for immediate priority ATC handling
4. Avoid abrupt or excessive manoeuvres.
5. No autopilot
6. Reduce angle of attack if aircraft tends to roll
7. Do not extend flaps
8. Do not retract flaps if extended.
9. Report conditions to ATC
10. Structural icing is least likely to occur in high clouds since they are formed mostly of ice crystals.
11. An encounter with ice pellets is indicative of freezing rain above.
12. You know that if you fly into rain that freezes on impact that the temperature is warmer at a higher altitude.
13. If you encounter wet snow, you known that the temperature is warmer than freezing.
14. A surface inversion is most frequently produced by terrestrial radiation on a clear calm night.
15. The surface temperature being below the dew point with the air and dew point below freezing causes Frost. Water vapour then sublimates directly as white and opaque ice crystals or frost.
16. Whenever icing is a hazard it will be forecast in sigmets and airmets.
17. Standing lenticular clouds are indicative of severe turbulence.

Tail Stall

This stall can occur when ice accumulates on the bottom of the horizontal tail surfaces to such an extent that the flow of air ceases to give the required download. The tail stall occurs on the bottom side of the horizontal tail surface. This lack of airflow can be even further reduced with the application of flaps and an increase in airspeed. Flaps will increase the downwash angle of the over tail air stream and increase the negative angle of attack. This can result in an abrupt nose down attitude and descent. The recovery is completely different from a normal stall recovery. Flaps are removed. Power is reduced and the yoke is pulled back. Pipers are subject to this more than Cessnas.

The do not use flaps if icing exists or is suspected. You will not be able to see ice on the bottom of the horizontal tail but any ice accumulation will occur there first. Fly the approach at a speed that will account for ice created drag but not extra fast that will increase the downwash on the tail surface. More downwash increases the tail stall possibility.  So long as airflow stays attached to the bottom of the tail, it is flying. You will have control and down pressure from the tail.

The full stall does not occur until both the low-pressure (top) of the wing and the (bottom) of the tail surfaces lose all their lift. This doesn't happen. With all low pressure surfaces having some effect the aircraft does not go straight down. The tail is being held down by low pressure below the horizontal tail surfaces. With ice on this surface it will have reduced effectiveness and power. If flaps move the centre of lift for the wings backward an abrupt nose down pitch is most likely to occur.

The tailplane will collect ice more readily than the wing. The collected ice will more adversely affect the tail-plane's downward loading than would the same amount of ice on the wing. Ice may be on the tail before appearing on the wing. Boot deicing on the tailplane is less effective than on the wing. An icing tailplane stall may be unrecoverable.  The icing you get may be quite different from the icing used for certification. The tailplane may be colder than the outside air temperature (OAT)

Advice: Don't use flaps if you suspect ice. Don't mess with ice. If the freezing level is on the ground, you won't be able to descend to warmer air.

Winter Clothing

Combine high-tech and traditional materials. It is easier to keep warm by wearing multiple layers. Inner lawyer should not absorb moisture and wick it away from the body. 1/4 of body head leaves via the head. Waterproof headgear may be the most important single survival item.

Pilots are optimists that believe bad things happen to other people. They believe that flying is so safe that there is no need to be prepared for catastrophe. Before leaving home you should prepare the 'what if' options. Whenever you go flying you should be dressed to walk home. You should have required items within cockpit reach. You should stay with aircraft and survive until conditions allow foraging. Short-term rescue is usually within a day. The greatest danger is exposure to conditions causing hypothermia. The right condition of wind, temperature, and moisture can expose anyone to hypothermia. The body loses heat most rapidly when wet.

Making your position visible can help rescue. Make a clearing, start a fire, and make large SOSs. Use common sense, have confidence in yourself and be patient. Prior planning, preparedness, practice and training will enable you to make the best decision possible.

Pilots fail more frequently than do any other facet of aviation.

Living with Weather Delays

Enjoy the weather delays they are going to occur more often than not…

1. Take a ground, simulator, or local flight lesson.
2. Make new friends
3. Visit the local ATC facilities
4. Go to an alternate airport and rent a car.
5. Now you have time to visit the local tourist trap.
6. A gambling casino can't be far.
7. Shopping is always an alternative
8. Look at the weather and be thankful you're down instead of up.

Weather Avoidance

Certain trips require better weather management than others. Understanding the weather you get is far more important than just making a collection of weather elements. A failure to understand mean that flight planning may proceed when it should be delayed, moved faster or skipped all together.

The preflight weather planning is the time to make flight decisions. Based on what you know about the weather you must decide if you are capable of making the flight in the face of forecast weather, terrain, and available facilities.

Once underway you are more in need of real-time weather. This means you will contact every HIWAS, ATIS, AWOS, ASOS and Flight Watch along the way. You will seek PIREPS because they are the most real-time weather you'll ever get. You will give PIREPS and stay in contact with Centre where you can get CWAs (Centre Weather Advisories) and CWSUs. Don't delay asking for help such as higher, lower, vectors, nearest airport.


Fog occurs when the air close to the ground reaches the dew point. Of the basic types of fog, radiation fog is the most common. Radiation fog forms on clear nights since clouds tend to warm the earth and air. Radiation fog is usually less than 300 feet thick. A light wind tends to make the fog even thicker. The rising sun lifts the fog and eventually breaks through. Any moisture on the earth evaporates and creates more fog. For this reason it is not unusual to have radiation last all day.

Advection fog comes with the on shore winds as it blows across a colder surface and causes humid air to form fog.  This fog is then blown or more likely 'sucked' inland as a layer of fog over the earth. This fog first covers the lowlands and can then be forced over hills and mountains as upslope fog.

When a moist front arrives the associated rain can form precipitation fog. If the air is near freezing this front will form ice fog. In some circumstances the start of an engine can provide the needed moisture to create ice fog.

Aircraft Considerations

Use POH to set manufacturers requirements
Get a cylinder head temperature gauge
Modify crankcase breather system
Check hose lines for flexibility
Check heater system
Get electronic monoxide detector
Get maintenance check of control cable tension
Do not feather propellers that may not unfeather
Keep battery fully charged or remove for warm storage
--Remove wheel pants
Do not recycle wet landing gear
Refill tanks immediately after landing
Refuel only when aircraft is level
Check quality of fuel
Imitation chamois will not filter water from fuel
Use only aviation approved filters
Have quick drains on all tanks
Inability to drain well may be indicative of ice in fuel.
Use anti-ice additives
Use proper heater to preheat engine compartment
Do not put heat directly on accessories
Store in heated hangar if available


Check POH procedures
Congealed oil and grease can affect engine and controls
Turn by hand before trying starter
Avoid over priming
Have fire guard present
On first try water/ice may condense on sparkplugs. Removal necessary.
Idle at RPM sufficient to warm plugs
Use carburettor heat to help vaporize fuel


Allow to warm up before use


Heated hangar is best option
Do NOT use water
Use alcohol
Don't fly until all snow and ice is removed

Blowing Snow

Check all openings and intakes
Check all controls
Check fuel vents


Braking may be nil
Ice exists below snow layer
Check ski shock cords and safety cables
Get help when taxiing down wind
Control surfaces will be ineffective


Cold weather both helps and hurts G.A. flying
Engine power increases 1 percent for each 10 degrees below standard temperatures
40 degrees of temperature can give a 10 percent power increase at normal settings
With reciprocating engines, use carburettor heat as required.
In some cases it is necessary to use carburettor heat to vaporize the fuel.
Gasoline does not vaporize as readily at very cold temperatures.
Do not use carburettor heat in such a manner that it raises the mixture temperature barely to freezing or just a little below.  In such cases, it may be inducing carburettor icing.
It may be advisable to use carburettor heat on takeoff in very cold weather.
An accurate mixture temperature gauge is a good investment for cold weather operation. It may be best to use carburettor heat on takeoff in very cold weather.
Do not over-boost supercharged engines
Turn on pitot heat
With engine baffles the engine will overheat on climb-out

En route

Carburettor Ice

The three types form between 32 and 80 degrees F even when visible moisture does not exist. When visible moisture exists the formation can occur between 15 and 32 degrees F. Partial throttle operation is the most critical time. Use carburettor heat prior to power reduction and use power during descents to maintain carburettor heat effectiveness.

Impact Ice

Moist air between 15-32 F on air scoops throttle plates
Worst at 25F

Fuel Ice

Forms throughout when moist air freezes through vaporization
Usually between 40 and 80 degrees F and relative humidity over 50%

Throttle Ice

Forms at or near throttle valve. Freezes due to venturi effect cooling by 5 degrees
Dangerous temperatures from 32 to 37 F

Ice Prevention

Ground check CH prior to takeoff
Use heat when carburettor temperature gauge is in the icing range.
Use heat on approach and descent

Signs of Ice

Loss of RPM or manifold pressure
Rough engine
Apply full carburettor heat
Expect engine to run rougher until ice melts

Snow, Ice, or Frost on the Wings:

Never attempt to takeoff with any ice or frost on the aircraft
Ice and frost can cause an aircraft to have sudden and violent stall characteristics.
Any stall caused by ice or frost may be unrecoverable
Below a layer of snow on the aircraft there is probably a layer of ice
Any ice caused roughness of the upper wing will cause a 10 percent increase in the stall speed
If airborne, any turbulence could result in an unrecoverable stall
Any precipitation that changes the wing's surface will increase the stall speed.
Flight should not be attempted where the wing's surface has been affected.
Stall speed and stall characteristics are determined with clean airfoils.
In icing conditions the usual cues for stalls and control problems may not exist.
Once stalled recovery may not be possible.
At best, large losses of altitude can be expected.
Only rapid and positive applications of power and AOA have any chance against configurations causing up to 50kts increase in stall speed.
Any use of the autopilot is likely to conceal icing problems.

On Icing

If weather briefing includes chance or reported icing…Don't go.
Avoidance begins with preflight planning
Don't fly winter fronts
It's worse over high terrain
0 to -10 C-degrees gives clear ice
-10 to -20 C-degrees gives rime ice
Freezing drizzle is worse that freezing rain.
180 is usually best decision
Pitot heat, C.H. and alternate air

What Is Icing?

Timely evasive action is the best option
Ice will be on the tail when you see it elsewhere.
Do not slow down nor use flaps when ice may be on the tail.
Have an Icing checklist the includes pitot heat and alternate air for starters.


There is no FAR that prohibits a Part 91 from flying in icing conditions.
If your aircraft has a placard, marking of AFM limits flying in ice, don't fly in ice.
AFM in the limitations section precudes flight into known icing.
A PIREP is the only way that a pilot can know of 'known icing'.
When the tops and bottoms of clouds exceed 4000' there is ice in there.
When freezing level is below the clouds there is ice in the clouds.
You can usually evade ice by changing altitude.
Waiting to change altitude is not an option.

Levels of Icing

Trace---you can see it but it does not sublimate nor accumulate

Light--In an hour the increase in ice would be a problem.

Moderate--accumulation rate requires diversion immediately.

Severe---You should have never entered the conditions.

If You Can't Avoid Ice

1/32 of ice on wing can reduce climb rate by 300fpm
Outside air temperature is critical from 0 to 20 below
Watch small-radius parts of the aircraft
Know your minimum enroute altitudes
Get on top as soon as you can, stay there as long as you can
Don't fly into a front or low pressure area
Be on the ground at night
Advise ATC
Make a 180
Cycle the propeller to throw off ice
Avoid the cloud tops
Fly faster without flaps

Icing Certification

Flight into icing is based upon maximum continuous and maximum intermittent icing conditions in mist conditions at icing conditions. No certification exists for flight in freezing drizzle or rain. Fly as fast as you can.

Cabin Heat

The air comes in through the nose of the aircraft as allowed by the cowling baffling. A flexible tube guides the air into the metal outer cover or shroud around the aircraft muffler. The region between the muffler and the shroud has a series of thin metal partitions that absorb the heat from the muffler and allows the ram air to flow and absorb the heat. This air is safely separated from the poisonous carbon monoxide passing through the muffler and exhaust pipe. When the cabin heat control is pulled it opens a door that allows the heated air from the interior of the shrouded area to enter the cabin by way of selected vents. If a leak should occur, and it can, the use of the cabin heater could allow carbon monoxide to enter the cabin and incapacitate or kill the occupants. The odour of other engine gases other than carbon monoxide is a clue that there is a leak. Carbon monoxide has no odour.

Snow Rhymes with No

When bad weather conditions are approaching, the sooner you leave the better.
Don't let ATC procedures delay a departure likely to be made hazardous by approaching conditions.
A negative for snow is that it often has ice beneath.
--Most winter ground accidents are caused by snow banks and berms created by ploughing.
Snow reduces visibility more than rain does.
Be prepared to use full control deflection when dealing with snow on the ground.
When snow covers the nosewheel 1/3 of the way consider inability to accelerate.
Snow storms average a life of 18 hours from first to last flake.
Snow ploughing begins with the longest runway, then taxiways and the ramp. G.A is always last.

Winter Fronts

Cold fronts move behind the thunderstorms
Warm fronts cause stratus, rain and low ceilings
Winter cold/warm fronts have close temperatures
Flying hazard is turbulence, winds, and clear icing near cold fronts.
The speed of the front movement directly related to wind velocity and extent of turbulence.
Winter warm fronts have terrible flying weather including freezing rain
Winter warm fronts have rime icing in stratus clouds.
Occluded front is two fronts with the worst weather of both relatively stationary.
Tops of winter clouds are lower and can be overflown.
Snow that is melting gives rise to severe fog conditions.
North-eastern movement of lows make that side a bad place to fly.
Northeast side of a low is a no-fly zone.
--Freezing level is region of freezing rain and clear ice.
Worst airframe icing occurs at -2 to - 5 degrees Celsius
If aircraft is capable, freezing layer is 1000 feet thick. Turning is best option to avoid precipitation.
Three number code identifies type of front, intensity and trend

Flying in Cold Conditions

Weather is more likely to clear than during summer.
Total operation of aircraft is more efficient in cold weather when in the air.
Ground operations are more difficult.
Keep your headset and flashlights warm.
A low battery can freeze.
A clogged oil breather can cause engine failure through loss of oil.
Daylight starts later and ends sooner. Carry more flashlights.
Thunderstorms are less likely.
Don't get into an airplane with snow adhering to you or your clothing.
Carry survival equipment
The worst wear occurs in the first few seconds of engine operation before oil becomes effective.
Preheating of the engine is the preferred way to get near instant oil where needed.
For most situations an engine and oil heating system is better than just engine or oil heating.
There are harmful effects to heating anything but the entire engine at the same time.
There are many negatives to continuous preheating.
--Break engine oil by rotating propeller if preheating is not available.
Fuel gets thicker and less volatile when cold. Warm the whole aircraft.
Wear appropriate clothing and shoes. Sleeping bag may be needed.
Silicone spray can keep propeller ice-free for a while.
Deice hinges and check control cables for free movement.
Cockpit engine controls must be free…check/
Turn on pitot heat during preflight to confirm operation and melt any internal ice.
Heating the cockpit includes the instruments with bearings subject to damage due to cold.
Another opinion is that more prime is required when cold.
Check alternate air as part of preflight.
Expect reluctance of engine to start, frosted spark plugs, and a weak battery.
Some find Continentals easier to start than Lycomings in cold weather.
When cranking have the primer out and ready to give a squirt when/if the engine fires.
Taxiing with any form of moisture on the pavement can induce loss of control.
Much of the hazard of snow on the ground is what it covers. Ice is worst.
Light frost can reduce lifting capability of a wing by 30 percent.
Depth perception is greatly compromised when snow covers everything.
Under certain combination of snow on the ground and clouds in the sky where will be no horizon.
A flying arrival into colder conditions means actual altitude is lower than indicated altitude.
Proper crosswind control positions are more vital than ever on a slick runway.
Ice with water on top is the most dangerous condition whether taxiing or landing.
Dew on the pavement can cause viscous slipperiness and reverted rubber hydroplaning.
Reverted rubber hydroplaning leaves a white skid mark. Runway has been steam cleaned by friction.
A worn tire hydroplanes more quickly than a new tire.
Braking is best with a 20 percent rolling skid.
A crosscut grooving of 1/4 inch slots gives a wet runway dry runway braking.

TKS (mix of glycol and alcohol)

Very expensive liquid ($22 per gallon) and spreading system costs $25,000+ per aircraft
Flows and protects entire aircraft from adhering ice.
Better than rubber boot systems

When It Gets Cold

Use lighter oil
Expect control cables to be slack.
Check breather tubes for frozen condensation
Use pitot heat to check for ice in pitot tube
Keep a full charge in the battery
Consider the use of Prist to prevent fuel icing
Remove pants with snow on the ground.
Take our time and do a complete preflight
Carry a winter survival kit.
Carry bright plastic marker material
Keep your warm covers in arms reach.
Have a carbon monoxide monitor
Preflight inside the hangar
Check hoses for flexibility and security
Check tires and pressure
Wipe the propeller with anti-ice fluid
Preheat engine and cockpit
Avoid hand-propping
Give the engine plenty of warm-up time
Slow to very slow taxiing
Keep weight off nose wheel
Avoid downwind taxiing
Consider not retracting gear.
If you use heater, open the air vents.
Avoid snow and ice when landing
Reduce takeoff roll by using flaps
Stay in ground effect until Vx.
Monitor flight watch to keep track of the weather
Any flight into icing is illegal.
Fly with pitot heat on.
Climbing is your first choice when in icing
Avoid steep angles of attack when climbing to avoid icing under flying surfaces..
Tops of clouds containing ice are higher near the centre of the low-pressure area.
Don't use your autopilot in icing conditions
Don't delay declaring an emergency
To descend keep power up to insure engine warming
Use full carburettor heat to enrich mixture
Avoid using flaps but increase descent speed
Blowing snow destroys depth perception
At -30F ice fog will form over the runway
Make approach 20/30 knots faster than usual when carrying ice
Use flaps unless airframe icing exists.
Make soft field landing with power on.
Avoid braking on rollout
--Keep full fuel aboard
Cover engine, vents and pitot.
Consider draining oil or light in engine compartment
Always shutdown using mixture

Use of electric hair dryer to warm engine during cold weather.

Winter Flying 

Do not ever hand prop an aircraft in the winter for many reasons ---Warm up the cockpit before takeoff if you want to rely on your instruments 
Expect stronger en route headwinds and crosswinds on landing ---Beware of tendency to over-prime in cold weather which is a fire hazard (review fire checklist) 
Snow covers most landmark references used in flying 
Check with destination airport for runway snow conditions since NOTAMS may not be current. 
Dress for survival and have a winter survival kit.