GM1 ADR.OPS.B.037(b) Assessment of runway surface condition and assignment of runway condition code
ED Decision 2021/003/R
SINGLE AND MULTIPLE CONTAMINANTS
When single or multiple contaminants are present, the RWYCC for any third of the runway is determined as follows:
(a) When the runway third contains a single contaminant, the RWYCC for that third is based directly on that contaminant in the RCAM as follows:
(1) If the contaminant coverage for that third is less than 10 per cent, a RWYCC 6 is to be generated for that third, and no contaminant is to be reported. If all thirds have less than 10 per cent contaminant coverage, no report is generated; or
(2) If the contaminant coverage for that third is greater than or equal to 10 per cent and less than or equal to 25 per cent, a RWYCC 6 is to be generated for that third and the contaminant reported at 25 per cent coverage; or
(3) If the contaminant coverage for that third is greater than 25 per cent, the RWYCC for that third is based on the contaminant present.
Figure 1: Single contaminant
(b) If multiple contaminants are present where the total coverage is more than 25 per cent but no single contaminant covers more than 25 per cent of any runway third, the RWYCC is based upon the judgement of the runway inspector, considering what contaminant will most likely be encountered by the aeroplane and its likely effect on the aeroplane’s performance. Typically, this would be the most widespread contaminant, but this is not an absolute.
(c) The structure of the RCAM is ranking the contaminants in the column ‘Runway surface description’ from top to bottom and is having the most slippery contaminants at the bottom. However, this ranking is not an absolute, as the RCAM by design is landing oriented and if judged in a take-off scenario, the ranking could be different due to drag effects of loose contaminants.