the Gruppe (plural Gruppen); the equivalent of a French or USAAC/USAAF group. Gruppen were part of a Geschwader (equivalent to a USAAC/USAAF wing or an RAF group) and the Geschwader were named according to their function. For instance, I./StG 77 was I Gruppe Sturzkampfgeschwader 77, which flew Junkers Ju 87 Stuka dive bombers. II./JG 26 was II Gruppe Jagdgeschwader 26, which flew Messerschmitt Bf 109 fighters, then switched to Focke-Wulf Fw 190 fighters. Each Gruppe was composed of three, sometimes four, Staffeln (singular Staffel) (usually 8–12 aircraft). Each Geschwader was composed of three Gruppen. By the time of World War II, some Commonwealth air force groups were commanded by air commodores (equivalent to brigadiers / brigadier generals and commodores) or even air vice-marshals (equivalent to major generals and rear admirals). They were somewhat analogous to a USAAF numbered air force (led by a brigadier general), with 200 to 400 aircraft. From 1943 to 1945, RAF Bomber Command groups were composed of several stations (air bases) and were analogous to USAAF wings. Commonwealth nations In the RAF (like the air forces of most other Commonwealth countries), a group is made up of several stations or wings, each of which typically controls two or more squadrons, so that a group normally includes six to 10 squadrons. When the ranks of the RAF were designed, an officer with the rank of group captain (equivalent to colonel and naval captain) commanded such a unit, although by the time of World War II, many groups were commanded by air commodores (equivalent to brigadiers/brigadier generals and commodores) or air vice-marshals (equivalent to major generals and rear admirals). Several RAF stations (air bases) are controlled by a particular group, although expeditionary air groups control expeditionary air wings directly. Groups are directly subordinate to a command (or, historically, to a tactical air force). In the Royal Navy's Fleet Air Arm, like some other Commonwealth naval air services, a group usually consists of two or three squadrons. United States US Air Force In the United States Air Force (USAF) a group consists of two or more squadrons, often functionally aligned within a wing. Per AFI 38-101 Air Force Organization (21 April 2015) a group is a "level of command between wings and squadrons. Groups bring together multiple squadrons or other lower echelon units to provide a broader capability." Prior to 1991, it was not unusual for a USAF support