What is a group of aircraft called?

Answer 1

The Question is not clear. The organization of an air force is made up of Wings, Groups, and Squadrons. These organizations are sometimes for administrative purposes but also could be how the units fought. For example a mission in WW2 would involve an entire Bomber Wing. But fighter aircraft may only go on a mission in Squadrons.

While operating on a mission, the fighter aircraft would form up into tactical flying formations. Each country over different periods of history experimented with different types of formations. Some of the fighter formations were:

Finger Four - four aircraft flying in a staggered formation shaped like how your finger tips are shaped.

Pairs - When going into combat, the figthers would try to attack with a leader and a wingman. The leader had the role of attack plane and the wingman would watch for any enemy and protect him.

The names of German WW2 units: Staffel, Geschwader, Jadegeschwader, Kampfgeschwader, Nachtschlachtgruppe(Tactical recon group), Fernaufklarungsgruppe, Erganzungsgruppe, Wettererkundungsstaffel(weather scouting squadron), Transportfliegergruppe.

Names of German WW1 units: K.E.K - Kampfeinsitzer-Kommandos (single seat fighter), Staffeln, Jasta (short for Jadgestaffeln)

French name: escadrille

Italian name: Squadriglia, Gruppo

2

formation or flight are often used for a group of aircraft flying together

Answer 2

A group of aircrafts are called a Formation or Flight.