flying corps; air force unit
Refers to a military aviation unit, such as a squadron or air corps. Often used in the context of air forces or naval aviation.
The flying corps introduced new fighter jets.
He belongs to the navy's air unit.
空軍 refers to an entire air force branch, whereas 飛行隊 is a smaller unit within it.
Compound of 飛行 (hikou, 'flight') and 隊 (tai, 'squad, corps').