In the U.S. Air Force (USAF), a boom operator is an aircrew member aboard tanker aircraft who is responsible for safely and effectively transferring aviation fuel from one military aircraft to another during flight (known as aerial refueling, air refueling, in-flight refueling, air-to-air refueling, and tanking). The name boom operator implies that one "operates a boom" (the flying boom), which is a long, extendable metal arm attached to the rear underside of the tanker that the boom operator connects to the fuel receptacle of a receiving aircraft (the receiver). The boom operator also controls the refueling drogue, a basket attached to a flexible hose that trails the tanker, when using the probe-and-drogue system. The USAF officially designates the boom operator career field as "In-Flight