Helicopter Wing adopted the term skvadron from the former Swedish Army Aviation for its units, which is squadron in its army company-equivalent meaning. In the early 2000s, the Swedish Air Force absorbed the Helicopter Wing as its fourth combat air wing. Unlike the US Air Force, where the name of the base and the units stationed at that base are not related to each other, the name of the wing (flotilla) is in general considered synonymous with the air base where the unit is stationed. For example, the air base where the F 10 wing is stationed (in Ängelholm) is commonly referred to as F 10 even though it is the name of the tactical unit. In general, this only applies as long as a wing is stationed at the base. Case in point is Uppsala-Ärna air base, an active military airport but since the tactical unit located there has been disbanded it is no longer referred to as F 16. These naming conventions have been inherited from the navy where Swedish military aviation has its roots. United Kingdom and Commonwealth During the infant years of combat aviation in World War I and specifically with the trench stalemate at the front military aircraft partially took over the reconnaissance role from the cavalry. With that in mind the British Royal Flying Corps adopted the squadron nomenclature. After the fusion of the Royal Flying Corps and the Royal Naval Air Service into an independent Royal Air Force, the new armed forces branch introduced its own system of ranks, with the commanders of squadrons becoming squadron leaders. The rapid sophistication in technology and combat tactics has led to increased requirements and qualifications of the officers in command positions and the commanders of RAF flying squadrons were upgraded in the post-World War II period from squadron leaders to wing commanders. Today RAF flying squadrons are battalion-equivalents, while combat and combat service support ground squadrons such as communications or administrative squadrons are company-equivalents and still usually commanded by squadron leaders. In the Air Training Corps of the United Kingdom and many Commonwealth nations, a squadron is a group of cadets who parade regularly. United States In the United States Air Force, the squadron is the principal organizational unit. An aggregation of two or more USAF squadrons will be designated as a group and two or more groups will be designated as a wing. USAF squadrons