Originally Posted by
B747-437B
CAT III-B requires RVR50 visibility (may vary slightly per each airline's operating manuals) and visibility often drops even below these minima. Prolonged periods of sub-CAT III-B conditions at major airports worldwide are actually very very rare, and DEL comes to mind as the only one where this is a virtually daily occurance for almost 10-15% of the year.
The resources required to certify aircraft and pilots to CAT III-B are huge. These costs are not something that can easily be justified for a single station in a larger network as long as a viable option to divert/reschedule/cancel exists.
In that case, we should just accept the reality and stop complaining. I am curious about what's unique about the location that DEL faces this frequent and prolonged sub CAT IIIB situation. It's the combination of meteorological conditions such as pressure, humidity, temperature and particulate matter. Maybe reducing particulate matter in air would help. The mount of construction going on around the airport can't help either.