Originally Posted by
atakacs
Only lurking in this thread but what does RVR 75 mean if there is no DH ? In effect does it still mean that if you don't see the runway at 75m you should go around ?
Definitely no, as you suspected.
For no DH operations unless there is a failure the pilot takes no decisions and actions apart from operating non-automated stuff like the reversers.
The min value of RVR = 75 is an arbitrary limit to enable vacating the runway and taxing. In the sense you'd at least will be able to repot where you are after getting lost.
There are two other values of similar nature:
125 m is the min requirement for manual roll-out.
300 m for manual landing (IIRC used to be 350, happy to be corrected on this one).
A proposed fully autonomous landing under nil/0 conditions exists on paper for quite some time, search the interweb for ICAO CAT IIIC. The technology does not exist yet.