PATNA, Feb. 4 -- Barely hours after the announcement of the Union finance minister Nirmala Sitharaman, granting in principle approval to three greenfield airport projects at Bihar's Rajgir in Nalanda district, Bhagalpur and Sonepur in Saran district in the Union Budget on February 1, a team from the Airports Authority of India (AAI), New Delhi, is headed for Rajgir on February 6 for obstacle limitation surface (OLS) survey that involves mapping the airspace around an aerodrome or a prospective aerodrome to assess possible infringements and recommend actions to remove or reduce obstacles, said airport officials on Monday....