Dilli door ast: IGIA arrival congestion bites air travellers

NEW DELHI: Delhi-bound travellers should brace themselves for delays over the next fortnight if their flight is scheduled to take off in peak morning or evening departure times. With its main runway closed, IGIA can handle a maximum of upto 32 arrivals an hour when easterlies are blowing here while the number of scheduled landings is much higher.

To prevent “extra” flights from taking off for Delhi only to hover here due to congestion; report low fuel; divert to nearby alternate airports & then wait there to fly to IGIA, the air traffic flow management (ATFM) system in place when easterlies are blowing asks planes to remain on ground in the origin cities only. Delhi air traffic control’s ATFM unit asks them to delay their departure to Delhi by a couple of hours so that they arrive here when the situation has got little better.

Once a plane gets delayed on any one sector — which is happening a lot this month on Delhi flights, — all other sectors it has to operate that day will be consequentially way behind schedule. With flights’ on time performance (OTP) taking a beating at India’s biggest airport, airlines’ punctuality across their network will continue to remain hit unless they reschedule and cancel some flights to align with IGIA’s real capacity.

Also read: IGIA flight delays: Closed runway to reopen in a fortnight & shut for ILS upgrade post peak summer travel season

“The problem is with arrivals in the current situation. IGIA is getting way too many flights, much beyond what it can handle. When easterlies blow and arrival capacity is further reduced, we have two options — delay in air or on ground. A delay in ground is better on many counts like avoid unnecessary fuel burn, carbon emissions and the stress & fatigue hovering/diversions causes to passengers & crew. So we regularly tell Delhi-bound flights to remain at other airports and take off for IGIA an hour or two behind their scheduled departure time,” said senior controllers.

The key word is “up to” 32 arrivals. “Not all planes move at the same speed, some are fast and some are slow. It’s like a road with a race car, an auto and a rickshaw. So accordingly we have keep the spacing between incoming aircraft. Also, runway 09/27 (closest to Dwarka) does not have rapid exit ways. Aircraft landing here need a separation of five nautical miles. On the other hand runways with rapid exit ways can have back to back arriving aircraft 3.5 nm apart as planes exit through runway quickly after landing,” said ATC officials. So actual arrival are closer to 27-28, they say.

Pilots, controllers and airport staff recall the night of April 11-12 when Delhi was hit by a strong thunderstorm. “All schedules had gone haywire. Around 3 am on April 12 there were so many arriving planes on the ground that the bay management simply collapsed,” said a pilot.

With its four runways and three terminals, Delhi Airport on an average handles about 2 lakh passengers and 1,400 flights daily. Take one terminal or runway out of the picture without reducing the flight-passenger load — as has been happening for the past 2-3 years, — the result is chaos. When other factors come into play, the situation gets even worse. The current instance is of runway closure with unseasonal wind flows. Last monsoon, a pillar collapse at terminal 1 meant the newly-expanded terminal could not be used 100% for almost a year. And before that, the winter of 2023-24 saw the main runway without CAT IIIB instrument landing system that led to flyers sweating in those cold months too.

Now the main runway’s instrument landing system (ILS) upgrade work has been deferred and it will reopen in about a fortnight. But by the time 10/28 does reopen, its month-long closure would have seen thousands of flights and lakhs of passengers facing long delays.