New Delhi, Feb 13 : Viability Gap Funding (VGF) of Rs 2,355 crore has been released to selected airline operators (SAOs) for operating UDAN (Ude Desh Ka Aam Nagrik) flights till January 2023, the Civil Aviation Ministry said on Monday. "As on January 1, a total number of 73 unserved or underserved airports including 9 heliports and A2 water aerodromes have been operationalised, since 2017, under the UDAN scheme," the ministry informed Rajya Sabha. "UDAN is a self-financing scheme. VGF of around Rs 2,355 crore has been released to Selected Airline Operators as on January 31, 2023 for the operation of UDAN flights," it said. In written replies, the ministry said, "The government has approved the 'Revival of unserved and under-served airports' scheme for the revival and development of 100 unserved and under-served airports, helipad and water aerodromes by 2024." "Under the UDAN scheme, the unserved and underserved airports or airstrips namely Ludhiana, Adampur, Bathinda and Pathankot have been identified in Punjab for operation of UDAN flights till the completion of four rounds of bidding," the ministry said. UDAN flight operations from the Ludhiana, Adampur, Bathinda and Pathankot airports have been commenced by the Selected Airline Operators, the reply said. The Ministry of Civil Aviation had on October 21, 2016, launched the regional connectivity scheme -- UDAN -- to stimulate regional air connectivity and making air travel affordable to the masses. UDAN is a market-driven scheme where bidding rounds are conducted from time to time for covering more destinations and stations and routes under UDAN. /IANS