Butler National Corporation (OTCQB: BUKS), a leader in the growing global market for aircraft structural modification, maintenance, repair and overhaul (MRO) and a recognized provider of management services in diverse business groups, announces it’s subsidiary, Avcon Industries, Inc, received Federal Aviation Administration (“FAA”) approval of the installation of the Rockwell Collins AHC-3000A Attitude Heading Reference System into the Learjet Model 60