---
title: "Frost — EASA Definition · Avioverse"
description: "CS ADR-DSN.A.002, Regulation (EU) No 139/2014: ‘Frost’ means ice crystals formed from airborne moisture on a surface whose temperature is below freezing…"
url: "https://avioverse.aero/glossary/easa/frost"
---

# Frost

EASA defines “Frost” in one regulation. The wording below is reproduced verbatim from the EASA Easy Access Rules, with a link to the paragraph it comes from.

> ‘Frost’ means ice crystals formed from airborne moisture on a surface whose temperature is below freezing; frost differs from ice in that the frost crystals grow independently and therefore have a more granular texture.
>
> Note 1: ‘Below freezing’ refers to air temperature equal to or less than the freezing point of water (0 degree Celsius).
>
> Note 2: Under certain conditions, frost can cause the surface to become very slippery and it is then reported appropriately as downgraded RWYCC.

CS ADR-DSN.A.002 · Aerodromes · Regulation (EU) No 139/2014 · Easy Access Rules, 13 Mar 2026 revision · [Read CS ADR-DSN.A.002](https://avioverse.aero/regulations/easa/aerodromes/cs-adr-dsn/chapter-a-general#cs-adr-dsn-a-002)

## Also in the aviation glossary

- Frost FAA PHAK

  Ice crystal deposits formed by sublimation when temperature and dewpoint are below freezing.

## Defined in the same article

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- [accuracy](https://avioverse.aero/glossary/easa/accuracy)
- [aerodrome](https://avioverse.aero/glossary/easa/aerodrome)
- [Aerodrome beacon](https://avioverse.aero/glossary/easa/aerodrome-beacon)
- [Aerodrome elevation](https://avioverse.aero/glossary/easa/aerodrome-elevation)
- [aerodrome equipment](https://avioverse.aero/glossary/easa/aerodrome-equipment)
- [Aerodrome operator](https://avioverse.aero/glossary/easa/aerodrome-operator)
- [Aerodrome traffic density](https://avioverse.aero/glossary/easa/aerodrome-traffic-density-1)