What Pakistan airspace closure means for Indian carriers

medium nocaption120955441India in the early hours of May 7 (Wednesday) carried out precision strikes on nine locations in Pakistan and Pakistan occupied Kashmir (PoK). The ministry of defence said the operation was "focused, measured and non-escalatory".According to Reuters, several Asian airlines said on Wednesday they were re-routing or cancelling flights to and from Europe following the strikes. More than two dozen international flights were diverted to avoid Pakistan airspace. By Wednesday morning local time, airlines had cancelled 52 flights to or from Pakistan, according to flight tracking website FlightRadar24.Reuters reported that there were 57 international flights operating in Pakistan's airspace when India struck, according a Pakistan army spokesperson. Images from the flight tracking website later showed that the northwestern airspace of India and Pakistan's entire airspace were nearly free of civilian aircraft, barring a few flights.The changing airline schedules are set to further complicate operations in West Asia and South Asia regions for carriers, who are already grappling with a fallout from conflicts in the two regions.TOI report Pakistan had already shut its airspace to Indian carriers from the evening of April 24. The same day, India had taken some very strong steps against Pakistan, which it held responsible for the Pahalgam terror attack two days earlier. As India suspended the Indus Water Treaty and asked Pakistani citizens to leave the country within 48 hours, Islamabad hit back by closing its airspace to Indian ﬂights.Result? A three-hour Delhi-Tashkent ﬂight became a 6-hour haul. A breezy two-and-a-half-hour ﬂight from Delhi to Almaty became a ﬁve-and-a-half-hour ordeal. Indigo, which operates this route, was in an unenviable position: it was ﬂying twice the distance for the same fare. On April 27, the airline suspended its Almaty ﬂight. The next day, it suspended its Tashkent service.Air India, too, has taken a big hit. Its Delhi-New York non-stop, which used to take 14 and a half hours, now needs a stopover in Vienna because it is taking a longer route and needs to refuel. Earlier, it used to overﬂy the Pak airspace and burnt about 1,06,500kg of fuel (these are Boeing 777 aircraft), but now via Vienna, requires 1,25,500kg of fuel. Not only is it now taking longer to reach New York (about 19 hours), carbon emission has gone up too — from 336 metric tonnes to 396. 120924106 medium nocaption120924114 medium nocaption120924132Routes Have Got LongerThis is not the ﬁrst time Pak airspace has been shut to Indian carriers. It happened in 1971 (Indo-Pak War), 1999 (Kargil War), 2001-02 (after Parliament attack), and then in 2019 (following Balakot airstrikes).But it’s not just Pak airspace. Commercial airlines stopped using the Afghan airspace after the Taliban takeover in Aug 2021. After this, Air India started using the Hindukush route (Papa 500) for its Europe, UK & North America ﬂights to and from Delhi. This involved ﬂying from Delhi to North Pakistan, then over the Hindukush range, CIS countries, to further west. (This is no longer an option.)Then, when Russia invaded Ukraine in Feb 2022, many airlines stopped overﬂying Ukraine. Western airlines don’t overﬂy Russia too, though Indian, Chinese and Gulf carriers do.More recently, the Israel-Hamas conﬂict in Oct 2023 affected the airspace over Jordan and Lebanon, with airlines playing safe. Air India, too, avoided this airspace and changed course whenever conﬂict escalated.Pressure On MumbaiSince April 24, over 130 westbound international ﬂights taking off daily from northern and eastern airports — Delhi, Amritsar, Chandigarh, Lucknow, Jaipur, and Kolkata — are being rerouted south, where the Ahmedabad and Mumbai air trafﬁc control assign them altitudes and put them on to routes to overﬂy the Arabian Sea and reach the Muscat airspace. Once there, they turn north to overﬂy Iran and complete the detour. In normal times, these ﬂights, after taking off, turned west to cross over to Pakistan and showed up on the radars of Lahore or Karachi air trafﬁc control before they moved into Iran.“Every time Pakistan shuts down its airspace, Mumbai air trafﬁc control gets a rush of rerouted ﬂights overﬂying from north and east India,” said a retired air trafﬁc controller. This time around, Mumbai air trafﬁc control has been handling about 130 rerouted ﬂights per day, while Ahmedabad’s handling about 80, passing most of them over to Mumbai. These ﬂights bunch up during peak hour, leading to dense trafﬁc at certain times of the day, such as 9.30pm to 11pm and 2am to 3.30am. medium nocaption120924146Lima 639 & Lima 301Yes, you read that right. They are the names of ﬂight routes the ATC gives.Lima 639 is a very recent invention. The 2019 airspace closure was the most challenging one. Overnight, about 500 ﬂights were rerouted south and showed up in the airspace controlled by the Mumbai air trafﬁc control. “All countries stopped using the Pakistan airspace. The current load is comparatively lighter with only about 130 additional rerouted ﬂights, mostly belonging to Indian carriers,” the retired air trafﬁc controller said.“The load was immediate and immense, too heavy for the existing air routes to handle,” he said. “That’s how the air route L639 was established — born out of necessity. Of the six routes taken by ﬂights from Mumbai to Muscat airspace, L639 is the most popular. Since the rerouted ﬂights come from the north, they try to catch the ﬁrst available route to the west without overﬂying the Pak airspace and that’s L639,” he said.L639 starts over Bhopal, links to Ahmedabad, Mundra, then overﬂies the Arabian Sea to end at a waypoint (a navigational checkpoint at a speciﬁc location in space) called ‘RASKI’, near Muscat.L301 is the next bet for airlines. It runs about 150 nautical miles (278 km) south of L639 and converges at RASKI.Along these two air routes, trafﬁc has been dense following the Pak airspace closure. Aircraft ﬂying west — from India to US, Europe — are assigned evennumbered altitudes and they cruise at 30,000ft, 32,000ft, 34,000ft, etc, up to about 42,000ft. Aircraft ﬂying from west to east into India are put on odd-numbered ﬂight levels — 29,000ft, 31,000, 33,000ft and so on. And along each ﬂight level or altitude on L639 and L301, aircraft are lined up one behind the other, separated by 20 nautical miles (37km).Along most other air routes over the sea, a horizontal separation of 50 nautical miles (93km) is maintained between aircraft ﬂying on a given ﬂight level. But in the past few years, the Mumbai air trafﬁc control, in a providential move, put procedures and practices in place that has enabled them to reduce the horizontal separation on L639 and L301. In Jan, trials were completed, and L639 and L301 became the ﬁrst two air routes in the Asia Paciﬁc to afford a reduced horizontal separation of 20 nautical miles.“With the reduced separation, more aircraft can be accommodated at each altitude,” he added. But the trafﬁc density has been so high on these two routes that ﬂights going from Mumbai to places like Shamshabad, Pune, Nagpur, Kolkata are being put on routes that are 50nm or 100nm (186 km) south of L301. So, even domestic ﬂights have been indirectly hit by the Pak airspace closure, he said. medium nocaption120920376Punishing schedule for AI pilots, crewTime ﬂies when you ﬂy. That was the old saying in Air India. But that’s not true anymore, at least for its crew members operating the North America long hauls. Since last month, with a refuelling halt in Europe, the same crew is having to put in four to six hours more.All four pilots are required to be in the ﬂight deck during take-off and remain there for half an hour after getting airborne. All of them are also supposed to be in the ﬂight deck for an hour and a half before landing. Now, with two take-offs and two landings, all four have to spend four hours in the ﬂight deck, as against only two hours during a non-stop.“That leaves 5-6 hours of cruise time during which one set ﬁrst takes rest for two and a half to three hours and then the other set for the same time. This cycle is repeated on the Europe-North America leg of the ﬂight. We are not machines that can switch on and off at will. Earlier, there was time to unwind and doze off. Now fatigue sets in and it gets very tiring when we reach the destination,” said a pilot, a sentiment shared by many others.The same is true for the cabin crew. After landing in North America, the crew gets a minimum gap of 36 hours after which they can operate back to India where their rest period has been extended from 120 hours to 132 hours.The general consensus among pilots is that if this is only for a month or so, then they can manage. But if this drags on, Air India will have to go for a crew change. ShowQuotesMeanwhile, AI is trying to altogether bypass Pakistan — for good — on its ﬂights to and from Europe and North America. It is charting out a route that involves ﬂying via Ladakh, China, and Russia for its ﬂights out of north India.However, this has its share of operational problems. The Tibetan terrain is at a very high altitude. Besides, India has yet to allow China to resume non-stop ﬂights to India, and there’s a big question mark on whether China will cooperate.