Bihar state was bifuricated into the states of Bihar and Jharkhand in 2001. No known warbirds exist in the state. There is Patna Civil airfield. The airfield was an RAF Station during the second world war and after. It was however turned into a purely Civilian airstation afterwards.
There have been rumours of a rare Hawker Hurricane fighter on display somewhere in Patna city. but no confirmed sightings have taken place. The aircraft was last seen reportedly in 1973. Mr. Asit Nag , who is a member of India’s Ministry of External Affairs was a resident of Patna right from the 50s to the early 80s. He does confirm that one Hawker Hurricane crashlanded at the Patna airfield, in which the Pilot fortunately survived. He confirms seeing the wreckage being there some twenty years later during the 60s. However no information as to what happened after that is available.