winter air crew operations briefing

Performing Missions For America

U.S. AIR FORCE A U X I L I A R YU.S. AIR FORCE A U X I L I A R Y

Winter Air Crew

Operations Briefing

Courtesy MN Wing/DOUpdated by ND Wing/DO

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ND Wing Cold Weather Operations

60-1 ND Wing Supplement Winter Operations:

November 15 Thru April 15All Wing Pilots operating

aircraft below 0 degrees F. are required to attend an annual cold weather flying course.Safety ProceduresAircraft Operational Requirements in extreme cold weather conditions

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Potential Winter Hazards

Aircraft IcingIce build-up at the top of the hangarIce build-up outside the hangar on the hangar ramp Ice on taxi-way or runwaySnow piles obscuring view or contacting wing tipFrost bite pre-flighting or re-fuelingFlooding engineEngine fireSlipping and falling

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Aircraft Temperatures & Wind-Chill Limitations

• Temperature: Wind-Chill: Limitation:

• Above 0°F. Above -30°F. None• 0°F. to-20°F. -30°F. to -50°F. 2 Occupant minimum• NO TRAINING,

NO T&G• Actual Missions

ONLY • Below -20° F.Below -50° F. DO Approval ONLY

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Aircraft Temperatures & Wind-Chill Limitations

• Temperature: Requirement:

• Below 0° F. Flight Release Officer has to be a pilot

• Below 0° F. Pilot attended annual cold weather flying course

• Below 0° F. Incident Commanders discretion if air support

is required

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Winter Kit ( Bug Eyes)

Located in the rear baggage shelf area

Reduces the opening of the cowling and the amount of airflow over the engine

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Winter kit ( Bug Eyes)

Pilot is responsible to install the winter kit to the cowling prior to flight when O.A.T is below 20 degrees F. or removal if the temperature is above 20 degrees F.

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Engine oil cooler

Located under the engine cover and is visible thru the oil fill access cover

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Engine oil cooler restrictor plate

C-172 OnlyOrange colorReduces air flow thru coolerInstalled and removed by MaintenanceN/A 182-T

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Engine Heater & Blanket

Aircraft are RequiredTo have the following 24/7 when

not in use:Tannis heater plugged inInstall engine blanket

This is required regardless of the date, any time the forecast ambient temperature is to be less than 30 degrees F. for more than a 24 hr. period

If plug-in is not available, engine MUST be preheated either by Tannis heater or an external heater before attempting a start.

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Pre-Flight

Following snow conditions, be extra careful on pre-flight to check:Inside pitot tubeStatic openingFuel ventsHeater intakeCarburetor air intakeTrim tabs and controlsTires & BrakesEngine oil Level

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Engine Oil Level

C-172 6 Quarts

C-182 8 Quarts

Overfilling just blows out

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Engine Crankcase Breather Tube

Located under the belly at the rear by firewallCheck for any Ice or other blockage

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Pitot Tube

Check for any restriction Check Pitot Heat

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Tire Inflation

Use a Tire Gauge to Check Prior to Each FlightPressure listed on gear strut and cover of Aircraft Information File

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Nose Strut

Check Clearance 3 fingersCheck for cracksCheck linkage

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Stall Horn

Check OperationSuction OperatedCheck for Restriction

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Brakes

Check padsCheck fluid leaksRotor thicknessCheck for IceKeep out of slush

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Plan for the Unexpected

Survival Kit (kit shown is not our kit)

3 Lbs of additional weight

Supplemental EquipmentCell PhoneGlovesHatBootsJacket

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Carbon Monoxide Detector

Carbon Monoxide Detector colorDateCheck exhaust

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Power Off Maneuvers

• Temperature: Limitations:

• 0° F. to +10° F. 1500 RPM or 15” of Manifold Pressure

• Avoid Shock Cooling

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Cold Weather Engine Starting

General rule for engine starters: after three, 10-second periods of operation, with a

pause between each, a five minute cooling period is requiredFailure to observe this can lead to starter overheating and damage/failureDO NOT Continue cranking until the battery is dead. This can cause a battery to freeze over a short period of time depending on the temperature.

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Engine Priming

PRIMING IS NOT NECESSARY if the A/C is plugged in & or in a heated hangar. Standard Procedure is NO PRIMING on C172!If the A/C has been out on the ramp and has cooled down, A slight amount of priming may be necessary. One pump! No More than Two!However, DO NOT OVERPRIME! This can lead to engine fire! flooding, washing down the cylinders and oil contamination.Throttle position should be slightly closer to idle position, on start-up, because of colder, more dense air

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Engine Start up

After start, DO NOT IDLE BELOW 1000 RPM - Cold temperatures increase probability of lead fouling of plugs.SLOWLY INCREASE THROTTLE. Too rapid of a throttle increase will cause the engine to stall in cold weather.Exercise constant speed props to prevent congealing of oil in prop dome

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Engine Operation

Allow extra time for oil to warm up after startup. 10-15 minutes at idle (1000 RPM) may be required to bring oil to minimum operating temperature

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Engine Operations

Plan descents earlierReduce power graduallyMaintain power throughout descentKeep fuel/air mixture leaned during descentUse Carburetor heat as required

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Fuel Considerations

Exercise special caution regarding any possible water contamination of fuel - water can freeze in fuel line; drain tanks and sumpCheck fuel selector valve for freedom of movement; statistics document cases of frozen selectorKeep tanks full (or to the level indicated in the NDWg Supplement to CAPR 60-1) to prevent moisture or frost inside tank

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Frost-Snow-Ice

FAR 91.527 Operating in icing conditions.(a) No pilot may takeoff an airplane that has-

(1)Frost, snow, or ice adhering to any propeller, windshield, or power plant installation or to an airspeed, altimeter, rate of climb, or flight attitude instrument system;(3)Any frost adhering to the wings or stabilizer or control surfaces, unless that frost, has been polished to make it smooth.

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Frost-Snow-Ice

Assuming that a thin coating of frost or ice is of no consequence, or that snow will blow off during takeoff is asking for trouble!Frost/snow/ice on wing and tail surfaces during takeoff has been a contributing factor in several aircraft accidents.

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Frost-Snow-Ice

All frost/snow/ice should be removed before attempting flight

For frost or ice, place aircraft in heated hangar, if possible (be sure water doesn’t run into control surfaces & re-freeze when aircraft is brought outside again)If no hangar is available, face aircraft control surfaces towards the sun to utilize/maximize radiation heating

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Frost-Snow-Ice

For snow, brush off (don’t count on snow blowing off during takeoff roll!)Note: Sometimes frost adheres to surfaces below snow coveringAlcohol, glycol or other ice-removal chemicals can be usedExercise extra care when warm aircraft has been pulled from hangar and left out in snow conditions

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Frost-Snow-Ice

“Unseen Frost”

Same conditions which cause frost formation on external surfaces can cause internal problemsMoisture in fuel tanks can freeze (good reason for topping tanks after flight) and can cause blockage of fuel flow to engine

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Frost-Snow-Ice

Typically, even small buildup of ice can cause 30% reduction in maximum coefficient of lift, decreasing the stall angle-of-attackDrag builds up, and if it exceeds max. thrust (full throttle), leads to descent, whether desired or not!Thrust also lost due to ice accumulation on propeller

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Frost-Snow-Ice

First place ice accumulates is small-radius or sharp-edged surfaces (fuel vent, temp. probe, etc)Small leading edge on tail surfaces make them more efficient collectors of ice (almost twice as fast as wing ice accumulation); tail may reach stall angle-of-attack before wing becomes problem

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Frost-Snow-Ice

Since horizontal tail produces “down” lift, stall results in tail going up, and aircraft nose pitching downFlap deflection increases downwash on tail, leading to higher (more negative) angle-of-attack, and earlier stall, if tail is iced

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Frost-Snow-Ice

Allow extra time for pre-flight planning, aircraft preparation and engine warm-upUnderstand the effects that frost, snow and ice have on an aircraftWhen flying in cold weather, keep in mind the impact that the temperature has on the aircraft and plan maneuvers accordinglyAvoid flight in/through visible moistureFly Safe!!

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Check Overhead Hazards

Check for overhead Ice or Snow Build-up prior to opening up

the hangar door

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Hangar Access

Remove snow as soon as possible to prevent frozen snow ridges and create a

safety hazard

Aircraft should be able to get in and out of hangar & ready for a

mission

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Cold Weather Operation

Questions?