NEW DELHI: An IndiGo flight from Kolkata to Patna made an emergency landing at Chaudhary Charan Singh International Airport on Friday after adverse weather conditions prevented it from landing in Patna, airport officials said.According to airport sources, weather conditions in Patna deteriorated suddenly on Friday afternoon, disrupting flight operations in the city.IndiGo flight 6E 6917, which was scheduled to land in Patna at 3.50 pm, was unable to receive clearance from air traffic control due to bad weather and continued circling in the air before being diverted to Lucknow.The aircraft landed safely at Lucknow airport at around 5.15 pm. Officials said there were 180 passengers and six crew members on board.The flight later departed for Patna after weather conditions improved.(With inputs from PTI)