The AAI chairman said the extension of the Jayaprakash Narayan International Airport at Patna was a bit problematic because of hindrances such as the adjacent railway line and the Sanjay Gandhi Biological Park. Its runway length is only 5,500 feet as against the 9,000 feet required for operating international flights.“One option before us is the IAF air-base at Bihta, and we are concentrating on it with a proposal to develop it into a civil enclave on 300 to 500 acres of land,” he said.Agrawal said the Bihta air base has a 8,200-foot runway which can be extended up to 9,000 feet.“We propose to shift the Patna airport to Bihta. We will approach the defence ministry for their nod for this and we hope there shouldn’t be any problem,” he said.There are 29 airports, aerodromes and airstrips in Bihar. Of them, 18 are under the state government, five under the defence ministry and five under the AAI. There’s also a private aerodrome at Kursela.Agrawal said there was a proposal for an airport in Bhagalpur. It has for now been shelved due to congested inhabitation there.