The 2008 Russian military reform planned during the term of Anatoly Serdyukov changed that. The main organizational change in the Ground Forces was the transition from a 4-level operational chain of command (Military District — Army — Division — Regiment) to a 3-level one (Military District — Operational Command (Army) — Brigade). The Air Force transitioned correspondingly to Military District — Operational Command — Air Base chain of command. The air bases combined geographically closely located flying units of various arms with ground support units. As the naval aviation followed the air force organizational practice it too adopted the air base organization. The separate air commands of the fleets (Air Force of the Northern Fleet, Air Force of the Pacific Fleet, Air Force of the Baltic Fleet and Air Force of the Black Sea Fleet) were disbanded and naval aviation assets adopted a three level operational chain of command including Military District — Fleet — Air Base.