Air War WW2 Portal 
September 1942
SATURDAY, 12 SEPTEMBER 1942
Twelfth Air Force: The following units arrive in England from the US: HQ Twelfth Air Force, XII Fighter Command and XII Air Force Services Command; HQ 319th Bombardment Group (Medium) and 437th, 438th, 439th and 440th Bombardment Squadrons (Medium) at Shipdham with B-26s (first mission 28 Nov); HQ 320th Bombardment Group (Medium) and 441st, 442d and 443d Bombardment Squadrons (Medium) at Hethel with B-26s (first mission 22 Apr);
MONDAY, 14 SEPTEMBER 1942
Twelfth Air Force: HQ Twelfth AF, XII Fighter Command, XII Air Force Services Command, and XII Bomber Command are attached to corresponding units of the Eighth AF in the UK;
The Eighth subsequently handles the buildup of the Twelfth by assigning a large number of its own units to the new AF (appropriately dubbed JUNIOR) and supervises its training.
The following combat units are transferred from the Eighth to Twelfth Air Force: HQ 1st Fighter Group and 27th, 71st and 94th Fighter Squadrons at Ibsley and High Ercall with P-38Fs; HQ 14th Fighter Group and 48th and 49th Fighter Squadrons at Atcham with P-38Fs; HQ 31st Fighter Group and 307th, 308th and 309th Fighter Squadrons at Westhampnett with Spitfire Vs; HQ 52d Fighter Group and 2d, 4th and 5th Fighter Squadrons at Goxhill with Spitfire Vs; HQ 60th Troop Carrier Group and 10th, 11th, 12th and 28th Troop Carrier Squadrons at Aldermaston with C-47s; HQ 64th Troop Carrier Group and 16th, 17th, 18th and 35th Troop Carrier Squadrons at Ramsbury with C-47s; HQ 97th Bombardment Group (Heavy) and 340th, 341st, 342d and 414th Bombardment Squadrons (Heavy) at Polebrook with B-17Fs; HQ 301st Bombardment Group (Heavy) and 32d, 352d, 353d and 419th Bombardment Squadrons at Chelveston with B-17Fs; and 15th Bombardment Squadron (Light) at Podington with DB-7s.
THURSDAY, 17 SEPTEMBER 1942
Twelfth Air Force: XII Ground Air Support Command is activated at Birmingham, Alabama; the only Twelfth Air Force command to be completely organized in the US, it eventually will proceed directly to N Africa as part of the Western Task Force (WTF).
HQ XII Fighter Command moves from Wattisham to Bushey Hall, England.
FRIDAY, 18 SEPTEMBER 1942
Twelfth Air Force: 12 British units--signal, observer, radar, and air warning--are attached to the XII Fighter Command in the UK.
Colonel Rosenham R Beam becomes Commanding Officer XII Ground Air Support Command.
TUESDAY, 22 SEPTEMBER 1942
Twelfth Air Force: Brigadier General John K Cannon takes command of the XII Ground Air Support Command.
WEDNESDAY, 23 SEPTEMBER 1942
Twelfth Air Force: Major General James H Doolittle assumes command of the Twelfth Air Force in Great Britain.
THURSDAY, 24 SEPTEMBER 1942
Twelfth Air Force: XII Ground Air Support Command is redesignated XII Air Support Command.
FRIDAY, 25 SEPTEMBER 1942
Twelfth Air Force: HQ 62d Troop Carrier Group and 4th, 7th and 8th Troop Carrier Squadrons arrive at Keevil, England from the US with C-47s.
SUNDAY, 27 SEPTEMBER 1942
Twelfth Air Force: Following a series of command changes between 16 and 27 Sep, Brigadier General Thomas W Blackburn becomes Commanding General XII Fighter Command.
The War Department assigns to the XII Air Support Command the units which are to constitute its force for the invasion of N Africa: the 5th Bombardment Wing [47th Bombardment Group (Light) and 68th Observation Group], the 7th Fighter Wing (33d and 81st Fighter Groups), and 10 signal, service, and engineer units of various sizes.
WEDNESDAY, 30 SEPTEMBER 1942
Twelfth Air Force: Brigadier General Delmar H Dunton assumes command of the XII Air Force Services Command.
Source:
COMBAT CHRONOLOGY OF THE US ARMY AIR FORCES
Jack McKillop
USAF (Airways and Air Communications Service)
1955-59
used sources by McKillop:
AIR FORCE COMBAT UNITS OF WORLD WAR II, Office of Air Force History, Headquarters USAF, 1961, ISBN 0-912799-02-1
COMBAT SQUADRONS OF THE AIR FORCE, WORLD WAR II, Office of Air Force History, Headquarters USAF 1982
THE ARMY AIR FORCES IN WORLD WAR II: COMBAT CHRONOLOGY, 1941-1945 by the Office of Air Force History, Headquarters USAF, 1973
