Structure of the United States Air Force The Structure of the United States Air Force refers to the unit designators and organizational hierarchy of the United States Air Force , which starts at the most senior commands . Current levels . Headquarters United States Air Force . The senior headquarters of the Department of the Air Force , Headquarters Air Force ( HAF ) consists of two staffs in the Pentagon : the Office of the Secretary of the Air Force and the Air Staff . Direct Reporting Unit . A Direct Reporting Unit ( DRU ) is an agency of the United States Department of the Air Force that is outside the bounds of the standard organizational hierarchy by being exclusively and uniquely under the control of Air Force headquarters alone , rather than reporting through a Major Command . The term " Direct Reporting Unit " comes from the fact that the unit reports directly to the Chief of Staff of the Air Force or to a designated representative on the Air Staff . A DRU has a specialized and restricted mission , meaning that it is a single purpose unit , usually to the exclusion of other duties , reporting to Air Force Air Staff alone . It is separate and independent from any organization structure or supervision : major command , numbered air force , operational command , division , wing , group , squadron , or field operating agency . It is a DRU because the unit ' s specific and focused duties , legal issues that necessitate the unit ' s independence , or other factors such as national security concerns . The Air Force has a very limited number of Direct Reporting Units : Field Operating Agency . The Field Operating Agency ( FOA ) is a subdivision of the Air Force , directly subordinate to an HQ USAF functional manager . A FOA performs field activities beyond the scope of any of the major commands . The activities are specialized or associated with an Air Force - wide mission , and do not include functions performed in management headquarters , unless specifically directed by a DoD authority . Major command . A major subdivision of the Air Force , the Major Command ( MAJCOM ) is directly subordinate to HQ USAF or the Air Staff . MAJCOM headquarters are " management " headquarters for a major segment of the AF and thus have the full range of functional staff . Numbered Air Force . The Numbered Air Force ( NAF ) is a " tactical " echelon directly under an operational MAJCOM that provide operational leadership and supervision . NAFs are structured to perform an operational or warfighting mission , often oriented to a specific geographic region . A NAF is directly assigned operational units , such as wings , groups , and squadrons . Wing . Wings have a distinct mission with a specific scope , reporting to the NAF or HQ USAF . Wings are made up of one or more groups , consisting of several squadrons , and usually commanded by a Colonel , but high visibility wings can have Brigadier Generals / O - 7s in command . Wings now encompass both operations and support activities ( Maintenance Groups , Mission Support Groups ) , and are usually one of three major types : Operational Wing , Air Base Wing , and Specialized Mission Wing . As of 30 September 2006 USAF had 120 wings , including 57 flying ( manned aircraft ) wings . Group . Made up of several squadrons and commanded by a Colonel / O - 6 , the group was of less visibility for some decades but came back to prominence during a transition to the " objective wing " organization in the 1990s . This reorganization changed the basic base command structure from the " Wing Commander / Base Commander " scheme to a single wing commander ( " one base - one boss " ) with multiple groups under his command . There are two general types of groups : Dependent ( operations , logistics , support , medical , or large functional unit ) ; and Independent ( a group with wing - like functions and responsibilities whose scope and size does not warrant wing - level designation ) . As of 30 September 2006 , USAF had 17 independent groups , nine of them flying establishments . Squadron . A Squadron is considered to be the basic unit in the USAF . Squadrons are usually made up of several flights ( typically four ) , a few hundred people , and eight to 24 aircraft . A squadron is usually commanded by a Captain to Lieutenant Colonel . Number digits apply ; 1 - 100 , 301 - 999 series for Air Force and Air Force Reserve squadrons ( i . e . 10th Fighter Squadron ) , and 101 - 299 series for Air National Guard ( i . e . 188th Fighter Squadron ) . Flight . The smallest formation officially recognized by the USAF , the Flight is the lowest level unit . A Flight usually ranges from a dozen people to over a hundred , or typically four aircraft . The typical flight leader is a Captain . Letter designations can be used , such as Alpha Flight , Bravo Flight , etc . Historical levels . Separate Operating Agency . " ( not in current use ) " Separate Operating Agencies ( SOA ) were major Air Force subdivisions directly subordinate to HQ USAF and has all the " prodecural ( administrative and logistical ) responsibilities " of a MAJCOM . In 1991 , most active SOAs changed in status to DRUs or FOAs . Operational Command . " ( not in current use ) " The Operational Command was a subdivision of the NAF , usually centered around a specific mission or unit . The numbering system of the Operational Command was usually defined by the NAF it was a part of , given in Roman numerals . For instance , the Tenth Air Force could have the X Bomber Command and the X Fighter Command as subordinate Operational Commands . Air Division . Air Divisions have existed since World War II when many of the numbered Air Divisions began as wings . There were both named and numbered Divisions , mostly Air Divisions . Recently HQ USAF gradually inactivated or redesignated Divisions recently in an effort to encourage rapid decision - making and to create a more flat organizational structure without " middle management " units , and as such Air Divisions are rarely used . Reserve components and auxiliary . Air National Guard . The Air National Guard , often referred to as the Air Guard , is the air force militia organized by each of the fifty U . S . states , the commonwealth of Puerto Rico , the territories of Guam and the U . S . Virgin Islands , and the District of Columbia of the United States . Established under Title 10 and Title 32 of the U . S . Code , the Air National Guard is part of a state ' s National Guard and is divided up into units stationed in each of the 50 states and U . S . territories and operates under their respective state governor or territorial government . The Air National Guard may be called up for active duty by the state governors or territorial commanding generals to help respond to domestic emergencies and disasters , such as those caused by hurricanes , floods , and earthquakes . With the consent of state governors , members or units of the Air National Guard may be appointed , temporarily or indefinitely , to be federally recognized members of the armed forces , in the active or inactive service of the United States . If federally recognized , the member or unit becomes part of the Air National Guard of the United States , which is one of two reserve components of the United States Air Force , and part of the National Guard of the United States . Air National Guard of the United States units or members may be called up for federal active duty in times of Congressionally sanctioned war or national emergency . United States Air Force Reserve . Although a major command , the U . S . Air Force Reserve Command is often thought of as a component ; the difference being that a component has relative autonomy from the parent ( in this case the U . S . Air Force ) , but a command has reporting commitments to the parent and is considered a sub - part of the parent organization . Civil Air Patrol . Civil Air Patrol ( " CAP " ) is a Congressionally chartered , federally supported , non - profit corporation that serves as the official auxiliary of the USAF . It performs three congressionally assigned key missions : emergency service s , which includes search and rescue ( by air and ground ) and disaster relief operations ; aerospace education for youth and the general public ; and cadet programs for teenage youth . In addition , CAP has recently been tasked with homeland security and courier service missions . CAP also performs non - auxiliary missions for various governmental and private agencies , such as local law enforcement and the American Red Cross . The program is established as an organization by Title 10 of the United States Code and its purposes defined by Title 36 . While CAP is sponsored by the USAF , it is not an operating reserve component under the Air Force or the federal government . Other generic designations . In addition to the aforementioned unit structures , the USAF has used , and still uses , a variety of other designations to identify organizations . These organization designations include :