The United States Air Force (USAF)

The United States Air Force (USAF) is the air service branch of the United States Armed Forces and part of the civilian-led Department of the Air Force, which is led by the Secretary of the Air Force. The military head of the U.S. Air Force is the chief of staff of the Air Force, who is assisted by the vice chief of staff of the United States Air Force and chief master sergeant of the Air Force. It achieved independence on 18 September 1947 from the U.S. Army, but directly traces its history through the United States Army Air Forces, United States Army Air Corps, United States Army Air Service, the Division of Military Aeronautics, Aviation Section, U.S. Signal Corps, to the birth of Aeronautical Division, U.S. Signal Corps on 1 August 1907.

The U.S. Air Force is composed of the Regular Air Force, United States Air Force Reserve, and United States Air National Guard. The U.S. Air Force is organized into nine major commands, which conduct the majority of the service's organize, train, and equip functions and command forces attached to the combatant commands.

The Air Force's major commands are:

· Air Combat Command: Provides fighter, attack, intelligence, cyber, combat rescue, and air force ground forces to combatant commanders.

· Air Education and Training Command: Recruits, educates, and trains airmen and develops Air Force doctrine

· Air Force Global Strike Command: Operates the Air Force's strategic bomber and intercontinental ballistic missile forces as United States Strategic Command's joint force air component.

· Air Force Materiel Command: Develops, maintains, and acquires systems and materiel.

· Air Force Reserve Command: Manages Air Force reserve forces.

· Air Force Special Operations Command: Conducts special operations with aviation and Special Tactics Commandos as United States Special Operations Command's joint force air component.

· Air Mobility Command: Conducts airlift and air refueling operations as United States Transportation Command's joint force air component.

· Pacific Air Forces: Conducts air operations as United States Indo-Pacific Commands joint force air component.

· United States Air Forces in Europe - Air Forces Africa: Conducts air operations as United States European Command's and United States Africa Command's joint force air component.

The U.S. Air Force's field structure is broken into several subdivisions under its major commands:

Numbered air force / Named air force: Consists of multiple wings with a geographic or functional assignment commanded by a general or lieutenant general.
 
Wing: Consists of two or more groups commanded by a brigadier general or colonel. Wings typically contain an operations group, maintenance group, mission support group, and a medical group. There are two types of wings: composite wings or objective wings. Composite wings operate more than one kind of aircraft and may be designated as self-contained units designed for quick air intervention anywhere in the world. Objective wings are based on a single purpose, such as an operational, air base, or specialized mission.
 
Group: Consists of two or more squadrons whose mission are similar or complementary commanded by a colonel.
 
Squadron: Consist of two or more flights commanded by a lieutenant colonel or major.
 
Flight: Consists of individual airmen, sections, or shops commanded by a captain.
 
Element / Section: Consists of two or more airmen led by a staff sergeant or senior airman.