Rising number of delays, cancellations and diversions due to bad weather at the Delhi airport is making Directorate General of Civil Aviation (DGCA) jittery, compelling it to swing into action to avoid “Mayday” call from flights like last year.”On Sunday, there were 30 diversions, which was really bad. On Monday, the operators (airlines) were called and asked for explanation. We looking to making it zero this year to prevent Mayday call, like it happened last year,” said a senior DGCA official, who did not want to be named.Last year, during the peak of winter, an aircraft that was diverted had to make an emergency landing for refuelling.A Delhi International Airport Limited (DIAL) spokesperson informed that on Tuesday there wereMonday, there were 10 cancellations, 5 diversions and 30 delays till 5 pm. The Delhi airport has 850-900 air traffic movements (ATMs) in a day. On Tuesday at least 27 flights were either delayed or diverted.The DGCA executive said during winters when the visibility on the runway dropped really low due to fog at the Indira Gandhi International Airport (IGIA), many airlines whose planes and crew were yet to get Category III bravo (CAT III b) approvals were not able to take off or land as per schedule.An Instrument landing system (ILS) of CAT III (b) allows landing and take-off even with a runway visibility range (RVR) of as low as 50 meters (Airbus) and 75 meters (Boeing).According to the executive, currently only Jet Airways, Air India and a few of the international carriers have aircraft and crew approved for CAT III b flying. IndiGo, Spicejet and others are still in the process of getting these approvals.”Some of these airlines are in the process of upgrading, which requires certain hours and approaches (auto-landing that is completely done with the help of the instrument at proper position),” said the DGCA executive.The higher the category, the sooner the ILS shuts down on internal detection of a fault condition. For instance, a CAT I localiser shuts down within 10 seconds of detecting a fault while a CAT III localiser takes less than 2 seconds to do so.The aviation regulator, which is working with the Delhi International Airport Ltd (DIAL), Airports Authority of India (AAI) and Air Traffic Controller (ATC) to reduce flight disruption due to fog, has made it mandatory for airlines to submit flight plans for the next day based on the weather forecast.”We have asked every airline to submit their flight plan for the next day in the evening with all crew and aircraft approval to avoid diversions and reduce inconvenience for the passengers. We have fog meeting everyday with representative from the airline, Delhi airport and ATC,” said the DGCA executive.Ashok Kumar, retired Airforce official who is a consultant with Aerosource (India) Pvt Ltd, said high diversions were a result of failure to monitor bad weather.”The problem is not so much of untrained pilots (for CATIII b) but that of scheduling of the flights. It is because of non-utilisation of trained pilots, who are diverted to flights that do not use their training,” he said.

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DGCA wants to bring down diversions to zero at Delhi airport