Originally Posted by
YourCptSpeaking
NightSky got it right...to land you need to have the required FLIGHT VISIBILITY, which if you have, will automatically guarantee you have the proper ceiling, so long as you don't bust minimums...basically this means that if you can see the runway environment at the MAP, then you have the required visibility and ceiling; if you can't, you don't.
In 121 this applies for precision approaches, and most non-precision approaches.
But each airline's OPSPECs are different, and many specify certain situations where both vis AND cig are limiting for commencing an approach. This is airline-specific and you don't need to know the details for an interview.