Assessment of Runway Conditions

Guidance for Aerodrome Operators relating to Winter Operations

The adverse weather experienced in the UK during the winter of 2009/2010 caused numerous difficulties for UK airports and their users. A common complaint from airline operators and aircrew at that time was the lack of timely, accurate and complete information about the state of the runways during periods of adverse weather capable of leading to the contamination of the runway surface. As a result, a series of joint CAA/industry meetings were held and consensus was reached on the reporting of surface conditions, as published in CAP 493 (Manual of Air Traffic Services Part 1).


Further to this, a joint CAA-industry working group has developed a new runway condition assessment and reporting matrix which was tested during a trial over winter 2011/2012. The mild winter led to few snow events and insufficient data was gathered, so the trial will take place again this coming winter at 16 aerodromes . This matrix is intended to help operators make better decisions about take-off and landing performance.


UK aerodromes have for many years operated a ‘back to blacktop’ policy during snow conditions. Although this is a goal supported by the CAA, there may be operational circumstances where it is preferable to keep the runway open despite a light covering of snow. Aerodrome operations staff will make tactical decisions at the time concerning continuing operations during adverse weather, including closure for snow clearing.

Useful Information Regarding Contaminated Runways

Operations on Contaminated Runways

AIC 86/2007 (Pink 126) - "Risks and Factors Associated with Operations on Runways Affected by Snow, Slush or Water"

Contact us

Aerodromes@caa.co.uk