An IndiGo flight heading to Kolkata on Friday returned to Ahmedabad after one of the Pratt and Whitney (PW) engines in the Airbus A320neo aircraft faced snag mid-air, according to senior government officials. "One of the engines of 6E125 Ahmedabad-Kolkata flight developed high vibrations mid-air. Therefore, the pilot returned the aircraft to Ahmedabad," the officials stated.