Believe this is the correct way to display one time Air Medal
http://usmilitary.about.com/library/milinfo/navawards/blairmedal.htmIndividual Award. Awarded to persons who, while serving in any capacity with the Armed Forces of the United States, distinguishes himself/herself by heroic/meritorious achievement while participating in an aerial flight under flight orders. A 3/16 inch bronze star is worn to denote first individual award of the Air Medal. Gold stars are worn to denote second and subsequent individual awards of the Air Medal.
Strike/Flight Award. Awarded to persons who, while serving in any capacity with the Armed Forces of the United States, distinguish themselves by meritorious achievement while participating in sustained aerial flight operations under flight orders. Bronze numerals are worn to denote total number of Strike/Flight Awards. Strike/Flight awards can only be approved within the parameters (area, time, etc.) established by the Secretary of the Navy; delegated authority of this award is specific in nature and always in writing.
Combat Distinguishing Device. The Combat Distinguishing Device may be authorized for single mission Air Medals for valor (heroism) after 4 April 1974.