Soviet underground refuelling network
 

Shot down on September 2, 1941, the SB of 40 BAP Black Sea Fleet flown by Lt.Vasiltschenko crashed near Kahovka,Ukraine , the Navigator who bailed out fell in German captivity . During his interrogation by Luftflotte IV he repeatedly indicated that the airfield at Karatchokmak was equipped with an underground refuelling network and some of the gas tanks or supply system was built underground. Did anyone came across such details and have more info about this and if during the German occupation of Crimea Luftwaffe made use of such network . Attached part part of the interrogation protocol.