Visiblity to RVR Conversion

[Shooting_Star]

Hello,

I am reading a little in the Jep manual,
I know we can convert VIS to RVR ( ex 400m by night with HI lights gets 800m RVR). But in the book it mentions also "not for take-off or any other required RVR minimum less than 800m or when RVR is reported".

What I wonder is the "or any other required RVR minimum less than 800m",
does this mean you can not use the conversion if RVR required is less than 800m? Can someone explain what they mean with this line ?

Thank you !

[WhySoTough]

Shooting Star,

Yes it means just that. If on your chart itself you need an RVR of 700 for example, in this case you are not allowed to convert your VIS of 400 that was given to you.
Also no conversions can be made when you are given an RVR ofcourse, and also for takeoff like you mentioned.

Make sense?

[Shooting_Star]

So that basically means that for standard ILS CAT1 550 RVR you can not use it ?

[WhySoTough]

That's right, you CAN'T.

[Shooting_Star]

Ok thank you !