At 1.30 am on Tuesday, Karachi ATC provided a wrong frequency (132.15) and asked them to report two-way with the ATC in Mumbai. Despite trying various combinations, the pilots were unable to connect to the Mumbai ATC. They later got in touch with Ahmedabad ATC and established contact with Mumbai ATC on the correct frequency. An official said ATC Karachi also provided a wrong expected time of arrival to the Mumbai ATC.
A senior Air India official, confirming the incident, said wrong frequency could change flight path, which may lead to a mid-air collision with another aircraft. All Air India flights going to the west or returning do not use Pakistani airspace, but a few flights out of Mumbai use it. Pakistan does not allow us to use their airspace for flights to west of India, the source said.