Kolkata, June 15 (ANI): A Royal Bhutan Airlines flight whose windshield cracked during its journey from Paro to Mumbai was forced to make an emergency landing in Kolkata on Sunday. All the passengers and crew members on board are said to be safe. The captain of the flight sought permission of the ATC for emergency landing as the aircraft suffered windshield crack during the flight, said an official at NSC Bose International Airport.