Low-visibility systems in place at IGI Airport to minimise flight disruptions

Following several flight delays due to fog-induced low visibility on Wednesday, officials aware of the matter said that at least three of the four runways have been equipped with CAT III instrument landing system (ILS) to reduce disruptions at the Indira Gandhi International Airport in Delhi.
“The airport has put in place strategic measures to improve resilience and reduce disruptions during low visibility which includes equipping advanced CAT III ILS in the three runways,” said one of at least two officials who confirmed the development.
The Delhi airport has four operational runways, the oldest being 27-09, followed by 28-10, southernmost runway 29L-11 R and 29R-11L. The 29L-11R was inaugurated by former civil aviation minister Jyotiraditya Scindia last year.
An ILS helps pilots land during poor visibility and is an important navigation system during extreme weather conditions, such as zero visibility. The systems have been installed at three runways, barring 27-09, where there are hurdles to its installation, officials said.
“The airport has implemented several strategic measures to enhance its resilience and minimise disruptions during low visibility periods…CAT III ILS and approach-lighting systems (ALS) have been installed at the three runways…enabling precision landing in low visibility conditions,” a Delhi International Airport Ltd (DIAL) spokesperson said.
An ALS is a critical safety feature during low visibility that helps pilots align their aircraft with a runway’s centreline during the final approach.
“The airport operator also conducts several meetings with airlines, AAI (Airports Authority of India) and other stakeholders to discuss the airport’s preparedness for the season and any changes or additions, if any,” the official said.
An airport official said, “The season’s first instance (of low visibility) was seen on Wednesday night when the visibility dropped below 100m, making the air traffic control activate ‘low visibility procedures’.”
“CAT III was in use when the visibility in Delhi dropped below 100m on Wednesday night. Due to the CAT III, few flights were delayed marginally and no cancellation was seen,” a second airport official said.
Aviation safety expert Captain Mohan Ranganathan said, “CAT III compliance of all three runways will help in reducing delays for arrivals and departures. Only when RVR is below 50 metres will it affect operations.”
“Configuring all three active runways to CAT III B and C at Delhi is a progressive step, but that will not solve the airport terminal congestion problem, check ins will continue to take time. DIAL must start on its committed and approved master plan, terminal 4, which is much needed now as total passenger throughput has breached 55 million passengers a year, the saturation limit for Delhi Airport,” Mark D Martin, CEO of Martin Consulting, said.