United States Air Force (USAF)

The United States Air Force (USAF) is the world's largest and most powerful air force in terms of expertise, and is a pivotal part of the United States' military power. It was formally established on September 18, 1947, with the purpose of "protecting the United States and its interests by force in air and space".The USAF is comprised of the USAF Secretariat, the Air Staff Office, and operational units, of which the highest executive authority is the Department of the Air Force, and the highest military command authority is the Air Staff. "The USAF is comprised of the Secretariat of the United States Air Force, the Air Staff, and combat units, with the Department of the Air Force as the top executive leadership organization and the Air Staff as the top military command organization.In February 2014, the USAF announced that it would be using iPhones and iPads to replace BlackBerry devices.