The Gleim Online Communication Course (OCC) is an interactive ground training course designed to increase pilots' safety, knowledge, and abilities in the area of aviation radio communications. From small, uncontrolled airports to the largest Class B airspace areas, OCC gives you practical knowledge that will enable you to not only participate in radio communications, but also to excel in them. OCC is a course that any new student pilot or returning veteran must try. This course is a structured, interactive, self-study review and certificate program delivered via the Internet.