Heathrow Airport had “nothing to do” with Air India’s direct evacuation flight from Calcutta to London not getting a slot there, the UK airport authorities have said in email to The Telegraph.

Metro had written to Heathrow Airport asking why the slot for AI1149 Calcutta-Heathrow on Thursday (September 17) had been cancelled. The flight had to go via Delhi, and passengers were delayed by six-and-a- half hours and had to remain on the plane for three hours at Delhi airport.

“I’ve double checked this with my operational colleagues and this issue had nothing to do with Heathrow,” Delia Williams-Falokun, senior press officer of Heathrow Airport, wrote in response.

Asked on Saturday by The Telegraph, an Air India official shifted the blame on the Civil Aviation Authority (CAA), the UK equivalent of India’s directorate general of civil aviation or DGCA. To get a slot at the London airport an airline has to seek permission from Heathrow Airport and the CAA, he said.

“Heathrow had given the slot but there was some confusion over getting permission from the CAA. At the last moment, Heathrow pointed out that the necessary clearance from CAA was not available and so they had rejected the slot, earlier given,” the Air India official said. “If Heathrow would have pointed out that the CAA permission had not come, then there could be persuasion from our side.”

Officials of several airlines, however, told Metro that getting clearances from the airport and the civil aviation regulatory body was the airline’s responsibility.

“We first get the slots at Calcutta airport for a particular flight and the permission from the DGCA before opening the bookings,” an official of an international airline that operates out of Calcutta said.

An official of another airline said getting a slot confirmed by the airport and the regulatory authorities was the basic criteria. Every airline has a dedicated team for that. “In the pre-Covid times, slots and permissions were taken months ahead. Now, there are permissions taken at shorter notice and so, the team has to work that extra hard to coordinate with the depart-ments concerned,” the official said.

Air India had announced twice-a-week evacuation flights under the Vande Bharat programme till October 24. But the first flight could not go directly to Heathrow and instead had to make a three-hour stopover at Delhi. The flight was delayed by four hours in Calcutta before that.

The Air India spokesperson had then said: “Last minute non-availability of slots at Heathrow Airport was communicated to us late on September 16 evening. This was something beyond our control as we had been assured of a slot till the sudden communication of its non-availability by the Heathrow authorities.”

On Sunday, the flight will go via Mumbai where the stopover time is less than an hour.

“We have already said that Air India could not fly direct to London from Calcutta because of last-moment slot constraints and non-availability of all the permissions. It is hoped that direct flights will operate soon with the green lights from the authorities,” the Air India spokesperson said on Saturday.

Till the permission is received, the flight will continue to go via Mumbai, the spokesperson said.

“Had Air India told passengers in advance about the fact that all permissions had not been taken, passengers would have had the choice of book-ing other flights with convenient timings,” Anil Punjabi, chairman, east, Travel Agents’ Federation of India, said. “Clear communication was lacking on behalf of the airline.”