Winter Flying Safety

October, 2008October, 2008

Winter Flying: Phases of Flight

Preflight (including Wx briefing)Preflight (including Wx briefing) Taxi & TakeoffTaxi & Takeoff EnrouteEnroute Approach & LandingApproach & Landing

Night CurrencyNight Currency– Due to shorter days, many flights may be completed at Due to shorter days, many flights may be completed at

nightnight– Are you Night Current ?Are you Night Current ?

Preflight Briefing / Planning

Briefing should include the following:Briefing should include the following:– Forecast freezing levels along your route of Forecast freezing levels along your route of

flightflight

– Airmets for icing conditions (Airmet Zulu)Airmets for icing conditions (Airmet Zulu)

– Cloud bases along your route of flightCloud bases along your route of flight

– Wx at destination airport including Runway Wx at destination airport including Runway ConditionsConditions

– These are in addition to “normal” preflight These are in addition to “normal” preflight itemsitems PIREPs, TFRs, significant weather, etc.PIREPs, TFRs, significant weather, etc.

VFR flights should be planned clear of cloudsVFR flights should be planned clear of clouds IFR flights should plan to avoid IMC when enroute IFR flights should plan to avoid IMC when enroute

altitude is at or below freezingaltitude is at or below freezing– The MEA may make this impossible during winter monthsThe MEA may make this impossible during winter months

Preflight Operations

Cold weather preflights tend to be Cold weather preflights tend to be abbreviatedabbreviated– Hurried due to cold weatherHurried due to cold weather– Insufficient time allowed for preheating, etc.Insufficient time allowed for preheating, etc.

Engine PreheatEngine Preheat– Electric oil pan heaters work well to ~ 30Electric oil pan heaters work well to ~ 30° F° F

Timer kicks on about 7:00 AMTimer kicks on about 7:00 AM– Pre-heater (Dragon) should only be used below 2Pre-heater (Dragon) should only be used below 200° F° F

ALWAYS be present when pre-heatingALWAYS be present when pre-heating

Removal of snow, ice, and frostRemoval of snow, ice, and frost– airfoil & control surfacesairfoil & control surfaces

A thin layer of frost (1-2 mm) can reduce A thin layer of frost (1-2 mm) can reduce lift by up to 33%lift by up to 33%

– Air intakes, fuel vents, pitot tube & static portsAir intakes, fuel vents, pitot tube & static ports

Preflight Operations (con’t.)

Fuel ContaminationFuel Contamination– Cold weather aggravates condensation of moisture in Cold weather aggravates condensation of moisture in

fuel tanksfuel tanks

Oil & Breather LineOil & Breather Line– Inspect breather for blockage due to frozen moistureInspect breather for blockage due to frozen moisture

Exhaust SystemExhaust System– Give the manifold a “good tug” to be sure it is secureGive the manifold a “good tug” to be sure it is secure

Pitot Static System & HeatPitot Static System & Heat– Be sure pitot tube & static vents are clear, and pitot Be sure pitot tube & static vents are clear, and pitot

cover is not frozen in placecover is not frozen in place– Check pitot heat for proper operation (Careful: HOT !!)Check pitot heat for proper operation (Careful: HOT !!)

Engine Start & Taxi

When starting engine, avoid tendency to over-When starting engine, avoid tendency to over-prime and/or to pump throttleprime and/or to pump throttle– Can cause engine fireCan cause engine fire– Refer to “Expanded” starting procedures in the POHRefer to “Expanded” starting procedures in the POH

Taxi slower than normal & avoid hard brakingTaxi slower than normal & avoid hard braking Avoid taxiing thru areas of snow & slushAvoid taxiing thru areas of snow & slush

– Snow & slush can be thrown into wheel wells (or pants) Snow & slush can be thrown into wheel wells (or pants) which could freeze & lock wheels or brakeswhich could freeze & lock wheels or brakes

Attempt to keep nose wheel on centerlineAttempt to keep nose wheel on centerline– Wingtips may strike snow drifts or other objectsWingtips may strike snow drifts or other objects

Strong wind can cause weathervaningStrong wind can cause weathervaning

Run-up & Takeoff

Run-UpRun-Up– Select a dry area (if possible)Select a dry area (if possible)

Plane will slide on snow/ice when run-up power Plane will slide on snow/ice when run-up power appliedapplied

– Keep Tach below 1000 RPM until Oil Temp is in greenKeep Tach below 1000 RPM until Oil Temp is in green

Takeoff from snow-covered runwayTakeoff from snow-covered runway– Consider soft-field takeoffConsider soft-field takeoff– Avoid braking – use rudder for steeringAvoid braking – use rudder for steering– Exercise caution when turning onto runwayExercise caution when turning onto runway

On takeoff roll, check “Airspeed Alive” to On takeoff roll, check “Airspeed Alive” to ensure that pitot tube cover is not frozenensure that pitot tube cover is not frozen

Effect of Slush/Snow on Runway

Slush DepthSlush Depth

½ Inch½ Inch

1 Inch1 Inch

1- ¼ Inch1- ¼ Inch

2 Inches2 Inches

Takeoff Distance IncreaseTakeoff Distance Increase

15 percent15 percent

50 percent50 percent

100 percent100 percent

Takeoff not possibleTakeoff not possible

Rule of Thumb: If you can’t walk without falling, don’t take off

Enroute

Cabin Heat & DefrosterCabin Heat & Defroster– Be aware of the effects of Carbon Be aware of the effects of Carbon

Monoxide poisoningMonoxide poisoning Headache, increased Headache, increased

respiration, drowsiness, respiration, drowsiness, blurred visionblurred vision

– If symptoms appear, discontinue If symptoms appear, discontinue use, open fresh air vents, and use, open fresh air vents, and land as soon as possibleland as soon as possible

CAUTION:

Enroute (Con’t.)

Pitot HeatPitot Heat– Use when in IMC or when Use when in IMC or when

flying in precipitationflying in precipitation– Be aware of effects of iced Be aware of effects of iced

up pitot tube or static portsup pitot tube or static ports

InstrumentStatic

BlockagePitot

Blockage

Altimeter"Freezes" at

constant valuen/a

Vertical Speed

Indicator

"Freezes" at zero

n/a

Airspeed Indicator

Under-reads in climb and over-

reads in descent

Over-reads in climb and

under-reads in descent

CAUTION: Monitor Enroute & Destination WeatherMonitor Enroute & Destination Weather– Check ATIS/AWOS, HIWAS, etc. along route of flightCheck ATIS/AWOS, HIWAS, etc. along route of flight– Get an updated briefing from Flight ServiceGet an updated briefing from Flight Service

Monitor outside air temperature Monitor outside air temperature Monitor leading edges, OAT probe, etc. for ice Monitor leading edges, OAT probe, etc. for ice

accumulationaccumulation

Enroute (con’t.)

Monitor enroute airspeedMonitor enroute airspeed– A loss of airspeed is an indication of airframe icingA loss of airspeed is an indication of airframe icing

Monitor engine power settingsMonitor engine power settings– A loss of RPM (fixed pitch prop) or Manifold Pressure A loss of RPM (fixed pitch prop) or Manifold Pressure

(constant speed prop) is an indication of carburetor ice(constant speed prop) is an indication of carburetor ice– Apply carb heat & leave on for 10-15 seconds or until Apply carb heat & leave on for 10-15 seconds or until

engine roughness has ceasedengine roughness has ceased

Approach & Landing

If airframe ice is suspected, do not extend flaps, and If airframe ice is suspected, do not extend flaps, and use higher than normal approach speedsuse higher than normal approach speeds

Listen to ATIS/AWOS (or unicom) for runway Listen to ATIS/AWOS (or unicom) for runway informationinformation– If not available, visually examine runway while in traffic pattern – If not available, visually examine runway while in traffic pattern –

check for snow drifts, vehicles, etc.check for snow drifts, vehicles, etc.

Plan for a soft/short-field landingPlan for a soft/short-field landing

Maintain directional control on snow covered runwayMaintain directional control on snow covered runway– Avoid hard braking – use rudder for steeringAvoid hard braking – use rudder for steering– Exercise caution when turning off runway or taxiwaysExercise caution when turning off runway or taxiways

Miscellaneous Items

Snow removal on apronSnow removal on apron– Refrain from driving/walking on fresh snow as it gets Refrain from driving/walking on fresh snow as it gets

compacted & forms ice.compacted & forms ice.– New hangar items to aid in snow removalNew hangar items to aid in snow removal

Snow Shovel - On the hangar wall behind N89549Snow Shovel - On the hangar wall behind N89549 Bucket of Sand - Next to N89549Bucket of Sand - Next to N89549

Engine Pre-HeatersEngine Pre-Heaters– All club aircraft now have pre-heatersAll club aircraft now have pre-heaters– Plug accessed via cowling oil doorPlug accessed via cowling oil door– Pre-heaters should be plugged in after flightPre-heaters should be plugged in after flight– There is an extension cord in the top drawer of the filing There is an extension cord in the top drawer of the filing

cabinet in the club room for overnight stays off-field.cabinet in the club room for overnight stays off-field.

Miscellaneous Items

Battery CartBattery Cart– The battery cart has been “retired”.The battery cart has been “retired”.– If the battery is dead, please see Jason.If the battery is dead, please see Jason.

Refer to Cold Start procedures in the A/C POHRefer to Cold Start procedures in the A/C POH– ““Expanded” procedures should be reviewed for cold Expanded” procedures should be reviewed for cold

weather startweather start

Hangar LightingHangar Lighting– On the hangar’s south wall (next to 45M), there is a On the hangar’s south wall (next to 45M), there is a

rotary timer if the hangar lights are out.rotary timer if the hangar lights are out.

Miscellaneous Items

Use of the “Dragon”Use of the “Dragon”– Confirm the mags are grounded, and position the prop vertically Confirm the mags are grounded, and position the prop vertically

(always turn the same direction as normal rotation)(always turn the same direction as normal rotation)– Position the Dragon in front of the aircraftPosition the Dragon in front of the aircraft– Remove the fire extinguisher, and place in a safe area away from Remove the fire extinguisher, and place in a safe area away from

the aircraftthe aircraft– Follow starting procedures on DragonFollow starting procedures on Dragon– Position nozzles inside both sides of cowlingPosition nozzles inside both sides of cowling– Pre-heat should take 15-20 minutesPre-heat should take 15-20 minutes– ALWAYS STAY IN THE IMMEDIATE VICINITY !!ALWAYS STAY IN THE IMMEDIATE VICINITY !!

Additional Fire Extinguisher on the hangar wall Additional Fire Extinguisher on the hangar wall behind 573.behind 573.

Summary

Winter provides spectacular scenery and great Winter provides spectacular scenery and great aircraft performanceaircraft performance

With attention to the elements, winter flying can With attention to the elements, winter flying can be both safe & enjoyablebe both safe & enjoyable

Questions ?Questions ?