Scene: DXB, one foggy early morning
UL153:
Good morning tower, UL153, ready for departure.
Tower:
Ah....good morning AirLanka, we have a slight problem, the RVR has just gone Tango Uniform.
UL153:
We can see three edge lights on each side of the runway (confirmed at 60m spacing...ICAO standard).
Tower:
Well then, if you have the required visibility, cleared for takeoff.
Nice folks in DXB.