u.s. air force birthday

font brand text logo poster cartoon advertising label presentation line banner number signage sign circle diagram design calligraphy national flag birthday emblem military america usa happy day symbol service armed aircraft vector air force united states background war appreciation theme september celebrating observance jet combat strength branch tribute threat graphic resources copy space annual usaf 18th post card assets operations airmen event department power campaign 1947 superiority defense security holiday concept template u s birthday 18 concept