Originally Posted by
Small cog
It is requirement to have the runway environment (features such as the runway threshold or approach lighting aids or other markings identifiable with the runway) in sight at all times. How else would you know where you are, when to turn and descend? It’s also important if you have to manoeuvre for a go around.
No, you are wrong. According to ICAO and EU ops, It is not a requirement to have the runway environment in sight at all times.
ICAO doc 4444 says:
Originally Posted by ICAO doc4444
6.5.3.3 An IFR flight may be cleared to execute a visual approach provided the pilot can maintain visual reference to the terrain and:
a) the reported ceiling is at or above the approved initial approach level for the aircraft so cleared; or
b) the pilot reports at the initial approach level or at any time during the instrument approach procedure that the meteorological conditions are such that with
reasonable assurance a visual approach and landing can be completed.
EU OPS adopted this in OPS 1.435 by defining a visual approach as
Originally Posted by OPS 1.435
An approach when either part or all of an instrument approach procedure is not completed and the approach is executed with visual reference to the terrain.
While the FAA has adopted an other definition, in most of the world, you can legally ask for and fly a visual approach without having the airport or runway in sight. You could ask for a visual approach (and get it) from 100 miles out, if you know that you will be able to visually find and navigate to the runway.
One example: If the pilot is familiar enough with the airport he could follow visually consecutive landmarks that he knows will bring the airplane on final in a position to land. Or, other example, During 'downwind' the runway might still be obscured by a ridge or hill, but the pilot can still position himself visually around the hill to final.
Don't confuse a visual approach during an IFR flight with a standard visual circuit in VFR!
For EU ops a minimum RVR of 800 m is required.