Bhubaneswar: May 13: Four Kolkata-bound flights landed at Biju Patnaik International Airport (BPIA) in Bhubaneswar today. They had to divert mid-air as Kolkata Air Traffic Controller (ATC) didn’t give landing permission to the flights and flights had to make emergency landing. As reports, heavy downpour occurred in Kolkata and Low visibility on the runway forced the pilots to divert towards the nearest airport. Flights 6E 172 Bangalore-Kolkata, 9W 907 New Delhi-Kolkata, 6E 708 Patna-Kolkata and AI 710 Mohanbari-Kolkata landed at Biju Patnaik International Airport (BPIA), Bhubaneswar.