As the bald eagle is the US National symbol and bird of prey, it represents a pilot's dominion over the wild blue yonder. Wings are a common motif, and especially the P-51 Mustang, if you flew during World War II. Other planes and jets serve like tattoos of lovers, or just fond reminders, along with squadron insignias and unit patches.
The Department of the Air Force is headed by the civilian Secretary of the Air Force who oversees all administrative and policy affairs. The Department of the Air Force is a division of the Department of Defense, headed by the Secretary of Defense. The highest ranking military officer in the Department of the Air Force is the Chief of Staff of the Air Force.