Escadrille

The first air escadrilles were formed in France before World War I, in 1912.[1] They were initially a loosely defined group of aircraft capable of similar tasks, in most cases not more than six aeroplanes in each.[2] During the war, the escadrille became the basic independent unit of aviation within the French armed forces. An escadrille was a homogeneous unit, armed with a single type of aeroplane, with permanent flying and ground personnel attached, motorised transport and tent hangars.[1] By mid-1915, the Armee de l'Air had grown to 119 escadrilles of 10 aircraft each: 14 of fighters, 50 of bombers and the rest reconnaissance, spotter and communications units.[1] While escadrilles initially operated independently, during the Battle of Verdun (1916), chasseur (fighter) escadrilles were formed into larger formations, for easier coordination.[3]

During World War II, French escadrilles usually fielded between 10 and 12 aircraft. Hence they were roughly equivalent to a German staffel, Italian gruppo or Polish eskadra (10 aircraft in 1939). This was in contrast to air squadrons of the British Commonwealth or United States, which usually had 12–18 aircraft, divided into two to four flights.

Until 1949, between one and four French escadrilles formed a groupe. Since then, however, escadrilles have been subordinate to escadrons. As such, groupes and escadrons are the equivalent of the German language terms gruppe and geschwader; and the English language terms "wing" and "group" (the definitions of which also vary from one nation to another).

Within the French Navy, the escadrille is a unit of the Naval Aviation or submarine force. In naval aviation, the escadrille is an aerial formation in the same way as the flotilla, but the navy uses the name of escadrille for support formations and that of flotilla for combat units.

For ships, the term escadrille designates a formation of submarines, while that of flotilla is used for a formation of surface ships (note that these are administrative formations).