U.S. Army Air Forces

Air Division:
3 to 5 Combat Wings (9 to 15 groups) – Used mainly in the European Theater, apparently.
Combat Wing:
3 x Groups – The basic tactical unit of the USAAF. B36 Wings would have deployed with just two groups.
Group:
4 x Squadrons – The basic operational unit of the USAAF. Usually based at a single airfield.
NOTE: All groups operate with 50% reserves; thus a B29 Bomb Group (VH), with 28 UE would actually have 42 aircraft.
Very Very Heavy Bombardment Group (Original Plan): 3
Squadrons, each with 6 aircraft for a total of 18 B36s
Very
Very Heavy Bombardment Group (Late 1948 Plan): 3 Squadrons, each
with 10 aircraft for a total of 30 B36s
Very Heavy Bombardment Group (1943): 4 squadrons, each with
7 aircraft for a total of 28. (2 crews per UE aircraft)
Very
Heavy Bombardment Group (1944): 3 squadrons, each with 10
aircraft for a total of 30. (1.7 crews per UE aircraft)
Heavy Bombardment Group: 4 Squadrons, each with 12 aircraft for a total of 48.
Medium Bombardment Group: 4 Squadrons, each with 13 aircraft plus HQ element of 5 planes for a total of 57.
Light Bombardment Group: 4 Squadrons, each with 13 aircraft plus HQ element of 5 planes for a total of 57.
Fighter Group: 3 squadrons, each with 25 aircraft for a total of 75.
Troop Carrier Group: 4 Squadrons, each with between 13 planes, for a total of 52.