Subhechcha Ganguly 
On Monday, Delhi’s air quality index (AQI) surged to a hazardous 481, leading to dense fog and prompting the Delhi International Airport Ltd (DIAL) to implement low-visibility procedures, according to a report by PTI. Airport officials explained that to minimize disruptions and enhance resilience during such conditions, the airport has deployed advanced CAT III Instrument Landing Systems (ILS) across all three runways. These systems, coupled with approach in-lighting systems (ALS), enable precise landings in low visibility and assist pilots in aligning their aircraft with the runway even in near-zero visibility. Low visibility procedures are triggered when the runway visual range (RVR) falls below 800 meters or when cloud ceilings drop below 200 feet.
In recent cases, visibility has fallen below 100 meters, leading to the activation of these procedures.Prior to implementing these measures, thorough testing of the systems is conducted, and the details are communicated to both air traffic control and airline operators.
