A Delhi-bound Indigo flight with 190 passengers from Mumbai was diverted to Ahmedabad on Wednesday after the pilot detected a crack on the aircraft's windshield midair.
It is suspected that the windshield cracked because of fluctuation in air pressure.
What caused the windshield crack has not been ascertained.
Sources told HT that the airline has to submit a report to the Directorate General of Civil Aviation (DGCA) on Thursday.
Usually windshields crack in turbulent weather, bird hits or turbulence caused by pilot error.