CAT I Vis and RVR: JAR-OPS vs ICAO?
For a CAT I approach when the RVR's are not available, according to JAR-OPS you should convert the reported visibility to RVR using the conversion table.
Lighting elements in operation RVR= Reported Met. Visibility x
Day/Night
HI approach and runway lighting 1·5/2·0
Any type of lighting installation other than above 1·0/1·5
No lighting 1·0/Not applicable
If we are at night, vis=300m and no RVR are available, using the table we have a converted RVR of 300 x 2= 600m.
If the required RVR is 550m can we try the approach?
The trouble is that according ICAO definition of CAT I, you need 550m of RVR or 800m of visibility BUT in the JAR-ops definition the 800m requirement is not mentioned anywhere.
Was this 800m requirement cancelled by JAR-OPS?
ICAO definition:
Category I (CAT I) operation. A precision instrument approach and landing with a decision height not lower than 60 m (200 ft) and with either a visibility not less than 800 m or a runway visual range not less than 550 m
JAR-OPS definition:
A Category I operation is a precision instrument approach and landing using ILS, MLS or PAR with a decision height not lower than 200 ft and with a runway visual range not less than 550 m.