sofia bulgaria ask russian aircraft corporation mig overhaul maintain 15 age mig-29 fighter jet four-year deal worth 81.3 million levs 49 million country defense ministry say monday nato eu member bulgaria need keep soviet-era aircraft operational plan buy eight new fighter jet hit another snag defense ministry virtually restart process yet send request proposals aircraft makers main contenders remain swedish manufacturer saab gripen jet portugal unite state secondhand f-16s italy secondhand eurofighter typhoons defence minister krasimir karakachanov say bulgaria may also send request boeing f-18 aircraft 1.6586 leva bulgaria ask russia overhaul mig fighter jet