Cold-Weather Maintenance Procedures

TASK 12-31-00-600-001-A
Cold-Weather Maintenance Procedures

1. Reason for the Job
To give data to help the operator with preventive maintenance procedures to keep aircraft downtime to a minimum.

NOTE: The source of all the data related to the fluids must be the manufacturer's recommendations for application and holdover times (supplied with the fluid). The ice protection procedures are given in the recommendations of the Society of Automotive Engineers (SAE). The recommendations are available on the website www.sae.org:

SAE AS 6285 (Aircraft Ground De-Icing/Anti-Icing Processes).
SAE AS 6286 (Training and Qualification Program for De-Icing/Anti-Icing of Aircraft on the Ground).

These procedures are Airbus recommended for de-icing and anti-icing requirements.
2. Job Set-up Information
A. Consumable Materials

REFERENCE	DESIGNATION
(Material No.07AAA1)	Deicing Fluid-- Type I Glycol Based
(Material No.07BAB1)	Deicing/Anti-icing Fluid-- Type II Glycol Based
(Material No.07BAC1)	Deicing/Anti-icing Fluid-- Type III Glycol Based
(Material No.07BAD1)	Deicing/Anti-icing Fluid-- Type IV Glycol Based

B. Referenced Information

REFERENCE	DESIGNATION
TASK 12-31-10-554-001-A	Return to Operation of an Aircraft Parked without Air Supply and with Electrical Supply
TASK 12-31-10-554-002-A	Return to Operation of an Aircraft Parked without Air Supply and without Electrical Supply
TASK 12-31-10-555-001-A	Turnaround Procedure with an Outside Air Temperature (OAT) of between -40 DEG.C (-40 DEG.F) and -46 DEG.C (-50.8 DEG.F)
TASK 12-31-10-555-002-A	Procedure to Park an Aircraft without Air Supply and with Electrical Supply
TASK 12-31-10-555-003-A	Procedure to Park an Aircraft without Air Supply and without Electrical Supply
TASK 12-31-10-555-802-A	Turnaround Procedure with an Outside Air Temperature (OAT) of between -40 DEG.C (-40 DEG.F) and -54 DEG.C(-65.2 DEG.F)
TASK 12-31-10-910-001-A	Seasonal Preparation
TASK 12-31-11-660-001-A	Cold Weather Maintenance - Anti-Icing Protection
TASK 12-31-12-660-002-A	De-Icing of the Aircraft in Power-Off Condition
TASK 12-31-12-660-003-A	De-Icing of the Aircraft in Power-On Condition
TASK 12-31-12-660-007-A	De-Icing of the Aircraft after a Landing with Snow on the Runway
TASK 12-31-21-660-001-A	Cold Weather Maintenance - Air Conditioning
TASK 12-31-23-555-801-A	Cold Weather Maintenance - Parking at very low outside temperatures - Communications
TASK 12-31-24-660-001-A	Cold Weather Maintenance - Electrical Power
TASK 12-31-25-660-001-A	Cold Weather Maintenance - Equipment/Furnishings
TASK 12-31-27-660-001-A	Cold Weather Maintenance - Flight Controls
TASK 12-31-28-660-001-A	Cold Weather Maintenance - Fuel
TASK 12-31-31-660-001-A	Cold Weather Maintenance - Indicating/Recording systems and Navigation
TASK 12-31-32-660-001-A	Cold Weather Maintenance - Landing Gear
TASK 12-31-35-660-001-A	Cold Weather Conditions - Maintenance of the Oxygen System
TASK 12-31-38-660-001-A	Cold Weather Maintenance - Water/Waste
TASK 12-31-49-660-001-A	Cold Weather Maintenance - Auxiliary Power Unit
TASK 12-31-51-660-001-A	Cold Weather Maintenance - Structure
TASK 12-31-52-660-001-A	Cold Weather Maintenance - Doors
TASK 12-31-70-660-002-A	Engine Start Procedure after Engine Cold Soak (with OAT below -40 DEG.C (-40 DEG.F))
TASK 12-31-71-660-001-A	Cold Weather Maintenance - Power Plant
TASK 12-31-71-660-802-A	Cold Weather Maintenance - Power Plant

3. Job Set-up
Subtask 12-31-00-941-050-A

A. Not Applicable

4. Procedure
Subtask 12-31-00-860-050-A

A. General
(1) Safe operation of the aircraft

Safe operation of the aircraft in cold weather conditions decreases downtime and delays in flight schedules.

(2) Cold soak definition
(a) The aircraft is in cold soak configuration when:

It is parked in cold weather, with an Outside Air Temperature (OAT) lower than 0 DEG.C (32.00 DEG.F) and
There is no electrical and no air conditioning power supply.

(3) Procedures for cold weather servicing
(a) Operators must prepare their special procedures for cold weather servicing.
This servicing must be adapted to their special conditions:

Their cold weather experience
The available equipment and material
The climatic conditions at their bases.

Subtask 12-31-00-860-051-A ** ON A/C NOT FOR ALL

B. Cold Weather procedures
(1) Aircraft cold-weather procedures

To do the anti-icing procedure: (Ref. AMM TASK 12-31-11-660-001)
To do the de-icing of the aircraft in the power-off condition: (Ref. AMM TASK 12-31-12-660-002)
To do the de-icing of the aircraft in the power-on condition: (Ref. AMM TASK 12-31-12-660-003)
To do the de-icing of the aircraft after a landing with snow on the runways: (Ref. AMM TASK 12-31-12-660-007)

(2) System cold-weather procedures
(a) Air conditioning: (Ref. AMM TASK 12-31-21-660-001).
(b) Communications: (Ref. AMM TASK 12-31-23-555-801).
(c) Electrical power: (Ref. AMM TASK 12-31-24-660-001).
(d) Equipment/furnishings: (Ref. AMM TASK 12-31-25-660-001).
(e) Flight controls: (Ref. AMM TASK 12-31-27-660-001).
(f) Fuel (Ref. AMM TASK 12-31-28-660-001) for:

The anti-icing additives
The fuel-tank water-draining procedure (if necessary).

NOTE: The fuel-tank water-draining procedure is not always done at each refueling. The Maintenance Planning Document (MPD) gives the frequency of the fuel-tank water-draining procedure.

(g) Indicating/recording systems and navigation: (Ref. AMM TASK 12-31-31-660-001)
(h) Landing gear: (Ref. AMM TASK 12-31-32-660-001)
(i) Oxygen system: (Ref. AMM TASK 12-31-35-660-001)
(j) Water/waste: (Ref. AMM TASK 12-31-38-660-001)
(k) APU: (Ref. AMM TASK 12-31-49-660-001)
(l) Structure: (Ref. AMM TASK 12-31-51-660-001)
(m) Doors: (Ref. AMM TASK 12-31-52-660-001)
(n) Power plant: (Ref. AMM TASK 12-31-71-660-001)

Subtask 12-31-00-860-051-B ** ON A/C NOT FOR ALL

B. Cold Weather procedures
(1) Aircraft cold-weather procedures

To do the seasonal preparation: (Ref. AMM TASK 12-31-10-910-001)
To do the anti-icing procedure: (Ref. AMM TASK 12-31-11-660-001)
To do the de-icing of the aircraft in the power-off condition: (Ref. AMM TASK 12-31-12-660-002)
To do the de-icing of the aircraft in the power-on condition: (Ref. AMM TASK 12-31-12-660-003)
To do the de-icing of the aircraft after a landing with snow on the runways: (Ref. AMM TASK 12-31-12-660-007)

The anti-icing additives
The fuel-tank water-draining procedure (if necessary).

NOTE: The fuel-tank water-draining procedure is not always done at each refueling. The Maintenance Planning Document (MPD) gives the frequency of the fuel-tank water-draining procedure.

Subtask 12-31-00-860-051-C ** ON A/C NOT FOR ALL

B. Cold Weather procedures
(1) Aircraft cold-weather procedures

To do the seasonal preparation: (Ref. AMM TASK 12-31-10-910-001)
To do the anti-icing procedure: (Ref. AMM TASK 12-31-11-660-001)
To do the de-icing of the aircraft in the power-off condition: (Ref. AMM TASK 12-31-12-660-002)
To do the de-icing of the aircraft in the power-on condition: (Ref. AMM TASK 12-31-12-660-003)
To do the de-icing of the aircraft after a landing with snow on the runways: (Ref. AMM TASK 12-31-12-660-007)

The anti-icing additives
The fuel-tank water-draining procedure (if necessary).

NOTE: The fuel-tank water-draining procedure is not always done at each refueling. The Maintenance Planning Document (MPD) gives the frequency of the fuel-tank water-draining procedure.

Subtask 12-31-00-860-051-D

DELETED

Subtask 12-31-00-860-051-F ** ON A/C NOT FOR ALL

B. Cold Weather procedures
(1) Aircraft cold-weather procedures

To do the seasonal preparation: (Ref. AMM TASK 12-31-10-910-001)
To do the anti-icing procedure: (Ref. AMM TASK 12-31-11-660-001)
To do the de-icing of the aircraft in the power-off condition: (Ref. AMM TASK 12-31-12-660-002)
To do the de-icing of the aircraft in the power-on condition: (Ref. AMM TASK 12-31-12-660-003)
To do the de-icing of the aircraft after a landing with snow on the runways: (Ref. AMM TASK 12-31-12-660-007)

The anti-icing additives
The fuel-tank water-draining procedure (if necessary).

NOTE: The fuel-tank water-draining procedure is not always done at each refueling. The Maintenance Planning Document (MPD) gives the frequency of the fuel-tank water-draining procedure.

Subtask 12-31-00-860-055-A ** ON A/C NOT FOR ALL

C. Cold Weather Procedures with an OAT between -40 DEG.C (-40.00 DEG.F) and -46 DEG.C (-50.80 DEG.F)
(1) The parking period must not be longer than 12 hours:
(a) If you park the aircraft without an air supply and with an electrical supply, do these procedures:

Procedure to park an aircraft without an air supply and with an electrical supply (Ref. AMM TASK 12-31-10-555-002)
Return to operation of an aircraft parked without an air supply and with an electrical supply (Ref. AMM TASK 12-31-10-554-001).

(b) If you park the aircraft without an air supply and without an electrical supply, do these procedures:

Procedure to park an aircraft without an air supply and without an electrical supply (Ref. AMM TASK 12-31-10-555-003)
Return to operation of an aircraft parked without an air supply and without an electrical supply (Ref. AMM TASK 12-31-10-554-002).

Subtask 12-31-00-860-056-A ** ON A/C NOT FOR ALL

D. Turnaround Procedure with an OAT between -40 DEG.C (-40.00 DEG.F) and -46 DEG.C (-50.80 DEG.F)
(1) If you do a turnaround (aircraft with an air supply and with an electrical supply), do this procedure:

Turnaround procedure (Ref. AMM TASK 12-31-10-555-001).

Subtask 12-31-00-860-056-B ** ON A/C NOT FOR ALL

D. Turnaround Procedure with an OAT between -40 DEG.C (-40.00 DEG.F) and -54 DEG.C (-65.20 DEG.F)
(1) The turnaround period must not be longer than 120 min (2 hours).
(2) Do the turnaround procedure with an OAT between -40 DEG.C (-40.00 DEG.F) and -54 DEG.C (-65.20 DEG.F) (Ref. AMM TASK 12-31-10-555-802).

Subtask 12-31-00-860-052-A

E. De-icing and Anti-icing Guidelines

CAUTION: DO NOT MAKE THE ANTI-ICING/DE-ICING FLUID IN TANKS HOT TOO MANY TIMES OR FOR LONG PERIODS. IF YOU DO, THE QUANTITY OF WATER IN THE FLUID WILL DECREASE AND THERE WILL BE A POSSIBLE DEGRADATION OF THE FLUID PERFORMANCE.

CAUTION: DO THIS TASK IN A LOCATION WITH SUFFICIENT DRAINAGE FOR THE ANTI-ICING/DE-ICING FLUIDS OR MOVE THE AIRCRAFT BEFORE THE ENGINE START. THE ANTI-ICING/DE-ICING FLUIDS CAN MAKE A POOL UNDER THE ENGINE AIR INTAKE. THIS CAN CAUSE THE ANTI-ICING/DE-ICING MATERIALS TO GO INTO THE ENGINE AND PREVENT ITS CORRECT OPERATION.

(1) De-icing is a procedure that removes frost, ice, snow and slush from the aircraft surfaces.
(2) De-icing and Anti-icing Methods
(a) De-icing fluids.
(b) Forced air or forced air mixed with de-icing fluid is permitted. Refer to SAE AIR6284 (Forced Air or Forced Air/Fluid Equipment for Removal of Frozen Contaminants).
(c) Infrared facilities.
(3) De-Icing and Anti-Icing Glossary
(a) De-icing fluids are usually applied hot. Typical de-icing fluids are:

Heated water
Newtonian fluids (ISO or SAE Type I Deicing Fluid-- Type I Glycol Based (Material No.07AAA1) )
Mixtures of water and Type I fluid Deicing Fluid-- Type I Glycol Based (Material No.07AAA1)
Non-Newtonian fluids (ISO or SAE Type II 07BAB1Deicing/Anti-icing Fluid-- Type II Glycol Based or Type IV 07BAD1Deicing/Anti-icing Fluid-- Type IV Glycol Based)
Mixtures of water and Type II 07BAB1Deicing/Anti-icing Fluid-- Type II Glycol Based or Type III 07BAC1Deicing/Anti-icing Fluid-- Type III Glycol Based or Type IV 07BAD1Deicing/Anti-icing Fluid-- Type IV Glycol Based fluids.

NOTE: At very low temperatures ( -15 DEG.C (5.00 DEG.F) and less), the effect of the fluids becomes less satisfactory. If the temperature is less than -15 DEG.C (5.00 DEG.F), it can be necessary to remove the contamination manually or with forced air.

(4) Obey the fluid manufacturer's instructions to increase the temperature of the de-icing and anti-icing fluids.
You must not make the de-icing and anti-icing fluids in tanks hot too many times or for long periods because:
(a) The quantity of water in the fluids will decrease.
(b) There will be a possible degradation of the fluid performance:

For Type I fluids Deicing Fluid-- Type I Glycol Based (Material No.07AAA1) , decreased quantities of water can cause unwanted aerodynamic effects.
For Type II 07BAB1Deicing/Anti-icing Fluid-- Type II Glycol Based and Type IV 07BAD1Deicing/Anti-icing Fluid-- Type IV Glycol Based fluids, thermal exposure and/or decreased quantities of water can decrease the fluid viscosity which will cause shorter holdover times.

One or more of the conditions that follow can decrease the fluid performance:

Small quantity of fluid used
Trucks that do not operate with their heating system on for long periods of time
High temperatures in fluid tanks
High temperatures in water tanks which directly touch the fluid tanks (no insulation between tanks).

(5) Anti-icing is a procedure that gives protection from the formation of frost or ice and snow accumulations on the treated surfaces of the aircraft for a period of time (the holdover time).
(6) Anti-icing fluids are usually applied cold directly onto a clean aircraft surface.
Typical anti-icing fluids are:

Newtonian fluids (ISO or SAE type I Deicing Fluid-- Type I Glycol Based (Material No.07AAA1) )
Mixtures of water and Type I fluid Deicing Fluid-- Type I Glycol Based (Material No.07AAA1)
Non-Newtonian fluids (ISO or SAE Type II 07BAB1Deicing/Anti-icing Fluid-- Type II Glycol Based or Type III 07BAC1Deicing/Anti-icing Fluid-- Type III Glycol Based or Type IV 07BAD1Deicing/Anti-icing Fluid-- Type IV Glycol Based)
Mixtures of water and Type II 07BAB1Deicing/Anti-icing Fluid-- Type II Glycol Based or Type III 07BAC1Deicing/Anti-icing Fluid-- Type III Glycol Based or Type IV 07BAD1Deicing/Anti-icing Fluid-- Type IV Glycol Based fluids.

(7) Non-Newtonian fluids (Type II or Type III or Type IV) have a viscosity that decreases when the airflow above the fluid increases.
(8) Newtonian fluids (Type I) have a low viscosity that only changes with temperature.
(9) Holdover time is the estimated time during which anti-icing fluids will prevent the formation of frost or ice and snow accumulations on the treated surfaces of the aircraft. The holdover time starts when the anti-icing treatment starts.
(10) De-icing/anti-icing is a combination of the de-icing and anti-icing procedures and it is possible to do this procedure in one or two steps.
(11) One-step de-icing/anti-icing uses an anti-icing fluid, usually hot. The fluid removes the ice from the aircraft and then stays on the aircraft and gives anti-ice protection for a short period of time.
(12) Two-step de-icing/anti-icing has two steps done independently:
First, do the de-icing of the aircraft (remove frost, ice, slush and snow accumulations).
Then, immediately after this, do an anti-icing procedure.

NOTE: Two-step de-icing/anti-icing is the procedure which Airbus and EASA recommend, because one-step de-icing, with Type II, III or IV material, causes unwanted fluid to collect in the aircraft.
After long periods of de-icing/anti-icing, it is recommended to do a check of the areas and spaces that are not in the aerodynamic airflows (such as balance bays and wing and stabilizer rear spars) for remaining fluid.

Subtask 12-31-00-860-053-A

F. General Information on Effects of Icing
(1) Aircraft performance certification is based on the performance of the aircraft with a structure that is clean, with no contamination.
(2) Ice, snow and frost or combinations of these will change the airflow and have an effect on lift and drag. They also increase the aircraft weight.
(3) On the ground, in specific weather conditions with very low temperatures, ice or snow accretion can occur in the lower part of the forward fuselage.
Ice or snow accretion can change the airflow.
This change can cause incorrect operation of the pitot probes, the static ports and the Angle of Attack (AOA) sensors.
This can cause incorrect indications on the related cockpit instruments.
(4) The aircraft and specially its surfaces that give lift and stability, must be aerodynamically clean. If they are not, safe operation is not possible.
(5) Safe operation is not possible, if the fuel temperature is lower than freezing point and the aircraft is in precipitation, clear ice can form on the wings (wing tank area), although the outside temperature can be as high as 15 DEG.C (59.00 DEG.F).
(6) An aircraft that is prepared for flight must not have ice, snow, slush or frost on the areas that follow:

The leading edge devices
The control surfaces
The upper wing surfaces
The engines
The aerodynamically quiet areas and the flight control cavities.

NOTE: The aerodynamically quiet areas and the flight control cavities are the areas and low points which are not on the aerodynamic airflow, where water, snow and ice can collect.

Thin hoarfrost is permitted on the upper surface of the fuselage if all the vents and ports are clear.

NOTE: Thin hoarfrost is a white crystalline deposit which usually develops equally on external surfaces on cold nights without clouds. It is sufficiently thin that you can see surface features (lines or markings) below it.

NOTE: A frost layer of a maximum thickness of 3.17 mm (0.1248 in.) is permitted on the bottom side of the wing between the front and rear spars. This is applicable if there is no effect on the take-off performance and if cold fuel caused it (low fuel temperature, OAT above freezing point and high humidity). This is not applicable to the bottom side of the Trimmable Horizontal Stabilizer (THS).

(7) A contamination check of the aircraft must include all parts of the aircraft. You must do this visual inspection from a position which gives a clear view of all the surfaces. Because you cannot always see collected clear ice easily, we recommend that you do an inspection of the critical surfaces (wings, vertical and horizontal stabilizers and rudder) with your hands.
(8) Weather conditions determine when de-icing/anti-icing of the aircraft is necessary.
(9) During checks on the ground, electrical or mechanical ice-detectors must not be used as an alternative to physical checks.
(10) If the aircraft arrives at the gate with the flaps/slats in a position other than fully retracted, you must do an inspection of these flaps/slats and de-ice them before retraction if necessary.

Subtask 12-31-00-860-054-A

G. De-icing and/or Anti-icing Equipment and Materials
(1) Type I Fluids
Type I fluids Deicing Fluid-- Type I Glycol Based (Material No.07AAA1) are usually used for aircraft de-icing and have only a small effect when used for anti-icing.
Type I fluids have a minimum of 80 % by volume of one of these products:

Monoethylene-glycol
Diethylene-glycol
Monopropylene-glycol
Or a mixture of these glycols.
The other 20% are:
Inhibitors, to prevent corrosion and increase the flash-point
Water and wetting agents.
These fluids have a low viscosity which only changes with temperature.
The freezing point of a water/glycol mixture will change with the quantity of water contained in the fluid. The lowest freezing point of concentrated Type I fluid will be approximately -10 DEG.C (14.00 DEG.F). A 60/40 Type I fluid-to-water mixture (freezing point lower than -50 DEG.C (-58.00 DEG.F)) will give protection for the lowest temperatures. But because of its lower viscosity, it will flow off the wing more easily. Thus a 50/50 Type I fluid-to-water mixture is usually used.

(2) Type II 07BAB1Deicing/Anti-icing Fluid-- Type II Glycol Based, or Type III 07BAC1Deicing/Anti-icing Fluid-- Type III Glycol Based, or Type IV 07BAD1Deicing/Anti-icing Fluid-- Type IV Glycol Based fluids have a minimum of 50% by volume of one of these products:

Monoethylene-glycol
Diethylene-glycol
Monopropylene-glycol
Or a mixture of these glycols.
The other 50% are:
Inhibitors, to prevent corrosion and increase the flash-point
Water and wetting agents, to help the fluid make an equal film on the aircraft surfaces
Thickening agents, to help the fluid to stay on the aircraft surfaces for longer periods.
The holdover time is longer for Type II or Type III or Type IV fluids than for Type I fluids.

(3) Holdover times
Holdover times are the estimates of the time during which the applied anti-icing fluid will prevent the formation of frost, ice and the accumulation of snow on the treated surfaces of an aircraft.
When you do a one-step de-icing/anti-icing procedure (not recommended by Airbus), the holdover time starts when you apply the fluid.
When you apply the first step of a two-step de-icing/anti-icing procedure, the holdover time starts when you apply the fluid.
The holdover times given are for general information only. Conditions can make the protection times shorter:

Severe weather
Strong winds and jet blasts
The age and condition of the fluid
The method used to apply the fluid.

(4) Equipment
(a) Mobile equipment
Truck-mounted de-icing/anti-icing equipment must usually be compatible with the application of Type I, Type II, Type III and Type IV fluids.
De-icing and anti-icing fluids can show degradation (for example, decreased viscosity) because of too much mechanical shearing. Thus you must only use compatible pumps and spraying nozzles recommended by fluid manufacturers.
To be compatible with SAE guidelines, centrifugal pumps can be used with Type I fluids.
(b) Static facilities
Specially made de-icing/anti-icing facilities, available at some airports, have spray nozzles installed on a gantry. The gantry moves at a given speed above the aircraft, or the aircraft moves below the gantry. The rate of fluid applied can be computer-controlled to apply the fluid regularly and quickly.
(c) Protective clothing
When you use de-icing/anti-icing fluids, you must obey the usual precautions related to chemicals. You must put on protective clothing, protective glasses and apply an approved cream on the exposed skin.

[Rev.10 from 2021] 2026.04.01 03:56:56 UTC