Delhi Fog: Why CAT III Doesn't End Flight Delays

• Dense fog at Delhi's Indira Gandhi International Airport caused over 100 flight cancellations and 300 delays.
• Operations are being conducted under CAT III conditions, the highest category of Instrument Landing System (ILS) for low visibility.
• CAT III allows landings in visibility as low as 50 meters, but delays persist if aircraft, pilots, or runways are not certified for it.
• The Instrument Landing System (ILS) provides azimuth and vertical guidance to pilots during low-visibility landings.
• Six Indian airports, including Delhi, support CAT IIIB operations, but no Indian runway is certified for CAT IIIC (zero visibility).

Why It Matters: It explains why Delhi flights face fog delays despite advanced tech.