How can a slush mixture of snow and alkali-organic salt de-/anti-icing substances affect the landing gear after retraction?

After landing gear retraction, the frozen slush deposits begin to melt, and the resulting liquid flows into the core of the carbon brake, further contaminating the carbon discs.

What abbreviations should be used in the RCR or AIP for potassium acetate and potassium formate fluids?

KAC for potassium acetate fluids and KFOR for potassium formate fluids.

Which abbreviation is used for sodium formate solids in the RCR or AIP?

NAFO is used for sodium formate solids.

What are the abbreviations for glycerine acetate fluids and sodium acetate solids?

GAC for glycerine acetate fluids and NAAC for sodium acetate solids.

Which abbreviations are used for ethylene glycol and propylene glycol fluids?

EG for ethylene glycol fluids and PG for propylene glycol fluids.

GM1 ADR.OPS.B.035(b)(3) Operation in winter conditions

Q: What is the effect of alkali-organic salt runway de-/anti-icing substances on carbon brakes?

The presence of alkali-organic salt creates a catalytic condition lowering the oxidation temperature of the carbon, resulting in structural deterioration of the carbon disc material and reducing the service life and long-term efficiency of the brakes.

Q: Why is it important for aircraft operators to have information on the de-/anti-icing substances used at the aerodrome?

It is important so that operators can assess the exposure of their aircraft to these substances and adjust their maintenance programme.

Q: During which phases of flight are carbon brakes and open wheel/bay exposed to alkali-organic salt runway de-/anti-icing substances?

During taxi, take-off and landing.

Q: What is the consequence of the catalytic condition created by alkali-organic salt on carbon brakes?

It lowers the oxidation temperature of the carbon, leading to structural deterioration of the carbon disc material and reducing the service life and long-term efficiency of the brakes.

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GM1 ADR.OPS.B.035(b)(3) Operation in winter conditions

ED Decision 2021/003/R

INFORMATION ON ALKALI-ORGANIC RUNWAY DE-/ANTI-ICING SUBSTANCES

During winter operations, the aircraft carbon brakes and open wheel/bay are exposed to alkali-organic salt runway de-/anti-icing substances during taxi, take-off and landing. A slush mixture of snow and alkali-organic salt de-/anti-icing substances could freeze onto the landing gear and inside the wheel well/bay. After landing gear retraction, the frozen slush deposits begin to melt. The resulting liquid flows into the core of the carbon brake, further contaminating the carbon discs. The presence of the alkali-organic salt creates a catalytic condition lowering the oxidation temperature of the carbon, resulting in structural deterioration of the carbon disc material and reducing the service life and long‑term efficiency of the brakes.

It is very important that aircraft operators have information on the de-/anti-icing substances used at the aerodrome that they operate to and from, in order to assess the exposure of their aircraft to these substances and adjust their maintenance programme.

The information, when provided in the RCR or in the AIP, should be given using the following abbreviations/words:

(a) KAC, for potassium acetate fluids;

(b) KFOR, for potassium formate fluids;

(d) NAFO, for sodium formate solids;

(e) NAAC, for sodium acetate solids;

(f) EG, for ethylene glycol fluids;

(g) PG, for propylene glycol fluids;

(h) UREA; and

(i) SAND.

Details

Source-Title: GM1 ADR.OPS.B.035(b)(3) Operation in winter conditions View latest amendments

Erulesid: ERULES-1963177438-18680 Compare versions

Domain: Aerodromes

Applicabilitydate: 12 August, 2021

Entryintoforcedate: 5 March, 2021

Regulatorysource: ED Decision 2021/003/R Navigate

Regulatorysubject: Part-ADR.OPS

Typeofcontent: GM to DR

Origin: EASA

Category: EAR