The RSG code in a METAR report provides information about the condition of the runway surface, which is crucial for pilots to assess before takeoff and landing.
The RSG code consists of various alphanumeric characters that describe factors such as the type of contaminants present on the runway (e.g., snow, ice, water, etc.) and the depth of any snow or slush. This information helps pilots determine the appropriate procedures and precautions to take during landing and takeoff, ensuring safe operations in various weather conditions.
Note – The RSG (Runway Surface Condition Group) code was indeed omitted from METAR reports following the introduction of the new SNOWTAM format in 2021. Instead of including RSG codes within METAR reports, information about runway surface conditions, including any contaminants such as snow, ice, or water, is now provided through SNOWTAMs (Snow Notice to Airmen). SNOWTAMs offer more detailed and standardized information about the condition of runways during winter weather, making it easier for pilots to assess runway suitability and take appropriate safety measures. However, this information is still included in some states (e.g. Azerbaijan and Russia).
RSG is 8-figure group which may be added to METAR for civil aerodromes. Following table will help you in decoding RSG code.
| First Two Digits | Third Digit | Fourth Digit | Fifth & Sixth Digits | Seventh & Eight Digits |
| Indicates the runway
27: Rwy 27 or 27L 77: Rwy 27 (50 is added to designator for runway – 27+50) 88: All runways 99: Repetition of the last message as no new information received |
Runway deposit
0: Clear and Dry 1: Damp 2: Wet or water patches 3: Rime or frost covered (depth normally less than 1mm) 4: Dry snow 5: Wet snow 6: Slush 7: Ice 8: Compacted or rolled snow 9: Frozen ruts or ridges /: type of deposit not reported |
Extent of runway contamination
1: 10% or less 2: 11% to 25% 5: 26% to 50% 9: 51% to 100% /: not reported |
Depth of Deposit
00: less than 1mm 01: 1 mm 02: 2 mm and so on till 90 90: 90 mm 91: not used 92: 10 cm 93: 15 cm 94: 20 cm 95: 25 cm 96: 30 cm 97: 35 cm 98: 40 cm or more 99: Rwy not operational due to snow, slush, ice, large drifts or runway clearance, but depth not reported. //: depth of deposit operationally not significant or measurable |
They can indication Friction Coefficient or Braking Action
28: friction coefficient 0.28 (example) 37: friction coefficient 0.37 (example) Or Braking Action Codes 91: Poor 92: Medium/Poor 93: Medium 94: Medium/Good 95: Good 99: Figures unreliable //: Braking action not reported |
If contamination conditions cease to exist, the abbreviation CLRD is used.
Example: 27CLRD93, Runway 27 cleared and braking action medium/good
Also Check: METAR and TAF Weather Reports Codes
