ARMY/NAVY COORDINATION
ANNEX B TO CINCPOA OPERATION PLAN NO. 10-45
COORDINATION OF OPERATIONS AND COMMAND RELATIONS
SECTION I Overall Responsibility.
SECTION II Definition of Areas and Boundary Lines.
SECTION III Air Operations.
SECTION IV Amphibious Operations and Control of Landing Forces.
SECTION V Areas of Naval Responsibility
I. OVERALL RESPONSIBILITY
1) The Joint Chiefs of Staff have made the following provisions for exercise of command for operation OLYMPIC:
a) The Commander in Chief, U.S. Army Forces, Pacific – Commander in Chief, Southwest Pacific Area:
i) Is charged with the primary responsibility for the conduct of Operation OLYMPIC including control, in case of exigencies, of the actual amphibious assault through the appropriate naval commander.
ii) Will make plans and preparations for the continuance of the campaign in JAPAN and cooperate with Commander in Chief, U.S. Pacific Fleet in the plans and preparations for the naval and amphibious phases thereof.
b) The Commander in Chief, U.S. Pacific Fleet and Pacific Ocean Areas:
i) Is charged with the responsibility for the conduct of the naval and amphibious (subject to paragraph (a-i) above) phases of the OLYMPIC operation, and will correlate his plans with Commander in Chief, U.S. Army Forces PACIFIC – Commander in Chief, Southwest Pacific Area.
ii) Will cooperate with and assist Commander in Chief, U.S. Army Forces, Pacific in his plans and preparations for, and conduct of, the campaign in Japan.
c) The land campaign and requirements therefore are primary in the OLYMPIC operation. Account of this will be taken in the preparation, coordination, and execution of plans.
d) Commanding General, TWENTIETH Air Force will cooperate in the plans, preparation, and execution of operation OLYMPIC and in the continuance of the campaign in JAPAN. At appropriate times, to be determined by the Joint Chiefs of Staff, the TWENTIETH Air Force will come under the direction of the appropriate commander for the support of operations directed above.
II. DEFINITION OF AREAS AND BOUNDARY LINES
1) The “Objective Area” is defined as the area south of latitude 32-30N enclosed by the arc of a circle having a radius of 120 nautical miles with its center at SATA MISAKI (30-00N, 130-40E).
2) The “Combat Area” is defined as the area north and west of a line drawn through the following points”
CHINA Coast at 26-30N
26-30N 123-00E
23-00N 123-00E
20-00N 130-00E
25-00N 135-00E
30-00N 135-00E
32-30N 140-00E
32-30N 155-00E
42-00N 155-00E
Coast of HOKKAIDO AT 42-00N
3) The “Coordinating Line” (bisecting the EMPIRE just west of the 135th meridian) is a line from the north coast of HONSHU at KINOSAKI following the railroad through WADAYAMA to HIMEJI and thence to the easternmost point of SHIKOKU.
4) The “POA-SWPA Air Search Responsibility Line” (delimiting the CinCPac and CinCSWPA areas of Air Search Responsibility) is a line drawn through the following points.
CHINA Coast at 26-30N
26-30N 123-00E
23-00N 123-00E
20-00N 130-00E
Equator at 130-00E
From the CHINA Coast at 26-30N to the 130th meridian at 20-00N, this line coincides with the boundary of the Combat Area.
III. AIR OPERATIONS
1) Coordination of Air Operations between Air Forces of CinCPac, CinCAFPac, and ComGenUSASTAF prior to and during the OLYMPIC Operation will be as follows:
a) Prior to X-8 and when the carriers of the U.S. Fleet are in position to attack objectives in JAPAN:
i) The principal tasks of fast carrier forces during this period are to destroy enemy naval and air forces, shipping and coastal objectives, protect sea communications in the Western Pacific, and to support other forces. These forces will assume primary responsibility for destruction of enemy aircraft and airdrome installations east of the following line, hereafter referred to as the coordinating line: From the north coast of HONSHU at KINOSAKI following the railroad through WADAYAMA to HIMEJI and thence to the easternmost point of SHIKOKU, with particular reference to those which cannot be reached effectively by the Far East Air Forces or by fighters of the USASTAF. When the fast carrier task forces are operating west of the coordinating line to accomplish their assigned naval tasks, they will operate against enemy air forces and airdrome installations in such a manner as to inflict maximum damage thereon and to ensure their own safety.
ii) The principal tasks of FEAF and Navy Air Forces, RYUKYUS, during this period are to destroy hostile air forces within range, ground forces and installations in Southern Japanese Archipelago, Naval Forces and shipping within range, and lines of communications contributing to maintenance or re-enforcement of hostile forces in Southern KYUSHU. FEAF and Navy Air Forces in the RYUKYUS will assume the primary responsibility for attack of hostile enemy aircraft and airdrome installations west of the coordinating line. Local coordination of FEAF, USASTAF and Navy Air Forces in their operations and selection of objectives to be attacked will be effected by local arrangement between the commander of the three forces represented.
iii) The primary task of the USASTAF is the destruction of hostile strategic targets. The forces of the USASTAF will assume the primary responsibility for destruction of strategic targets both east and west of the coordinating line.
iv) The Commander THIRD Fleet, or his Task Force Commanders; the Commanding General, Far East Air Forces, or his Air Force Commanders; the Commanding General, United States Army Strategic Air Force, or his Air Force Commanders; and the Senior Naval Air Commander at OKINAWA, will notify each other, CINCAFPAC, CINCPAC and COMGEN USASTAF of their strike intents as far in advance as is practicable.
v) This is particularly important when elements of the THIRD Fleet Carrier Task Forces strike west of the Coordinating Line, when elements of the FEAF or Navy air elements in the RYUKYUS strike east of the Coordinating line and when USASTAF strikes in either area.
vi) In emergency, the air commanders indicated above, may strike any hostile target. In this case or in case of a change in plans of attack on hostile objectives, these commanders will inform all air commanders concerned as promptly as possible.
b) From X-8 inclusive to an indefinite date later to be agreed upon by dispatch:
i) The THIRD Fleet will assume the primary responsibility for the destruction of enemy aircraft and airdrome installations east of the coordinating line.
ii) In addition to its planned operations within the objective area, FEAF will assume primary responsibility for the destruction of enemy aircraft and airdrome installations outside the objective area and west of the coordinating line. Coordination of FEAF and Navy Air Forces in the RYUKYUS in attacks on hostile objectives above set forth will be as in subparagraph “a)” above. ComGenFEAF will notify FIFTH Fleet when, because of weather or other reason, its counter air force mission cannot be performed.
iii) The FIFTH Fleet will employ its air forces primarily against hostile targets in the objective area, but will take such action as is required to cover targets outside the objective area in the event that FEAF, because of weather or other reason, cannot perform its mission.
iv) Agreements set forth in subparagraphs “a3)” and “a4)” above remain in effect. Agreements set forth in subparagraph “a5)” remains in effect except for the objective area.
2) Control of Aircraft in the Objective Area is exercised as follows:
a) During the amphibious phase of the operation, while control is exercised by CinCPac, land-based air elements operating in the objective area are controlled by CinCPac through a commander designated by him. The instructions of this commander wherever practicable are transmitted to the appropriate land-based air echelon through an Army Air Controller who accompanies the designated Naval Air Commander.
b) Similarly, after land-based air forces are established in the objective area and responsibility for air operations passes to the CinCAFPac, control of carrier based air elements operating in the objective are is exercised by the Army Air Task Force KYUSHU wherever practicable through a Navy Air Controller at the objective area.
3) Areas of responsibility for Overwater Air Searches are defined as follows:
a) North and east of the POA – SWPA Air-Search Responsibility Line (as defined in Section II, above) Cincpac is responsible for overwater air-search. This responsibility will be discharged by Fleet Air Wings ONE and EIGHTEEN as follows:
i) In the Combat Area west of Longitude 135 degrees east, Fleet AirWingONE has the responsibility for the conduct of over-water air-searches, initially under the direction of ComFIFTH Fleet.
ii) In the Combat Area east of Longitude 135 degrees east, Fleet AirWingEIGHTEEN has the responsibility for the conduct of over-water air-searches, initially under the direction of ComMARIANAS. These operations will e coordinated with the operations of ComTHIRD Fleet.
iii) Fleet AirWingEIGHTEEN under the direction of ComMARIANAS also has the air-search responsibility for the MARIANAS Area.
b) South and west of the POA – SWPA Air-Search Responsibility Line (as defined in Section II, above) CinCSWPA is responsible for over-water air-search. This responsibility is discharged by Fleet Air Wings TEN and SEVENTEEN under the operational control of CinCSWPA.
IV. AMPHIBIOUS OPERATIONS AND CONTROL OF LANDING FORCES
1) Control of the landing forces ashore will be exercised as follows:
a) The Commander FIFTH Fleet controls the amphibious movements and landing through Commander Amphibious Forces, Pacific Fleet who in turn controls the Attack Force of Group Commanders who are responsible for their amphibious operations at their respective objectives.
b) Control of the forces ashore passes to the Commander of each Assault Division, or each separate Landing Force, after his arrival and establishment ashore and upon his notification to the Commander of the corresponding Naval Attack Group that he is ready to assume control of his forces ashore. The commander of each Assault Division and separate Landing Force and the Commander of each Naval Attack Group promptly reports to his next senior Ground or Naval Commander the time he assumes or relinquishes control of forces ashore.
c) Control of forces ashore passes to each Corps Commander within his respective area of operations after his arrival and establishment ashore and upon notification to the Commander of the corresponding Naval Attack Force that he is ready to assume control of his forces ashore. Each Corps Commander and the corresponding Naval Attack Force Commander promptly reports to ComGenSIXTH Army and to ComPhibsPac, respectively:
i) The time each Division and separate Landing Force and its corresponding Naval Attack Group Commander assumes or relinquishes control of the forces ashore.
ii) The time he himself assumes or relinquishes control of the forces ashore.
d) Division, separate Landing Force and Corps Commanders who have assumed control of the next senior Naval Attack Force or Group Commander until their next senior Army Commander assumes control of forces ashore.
e) Control of forces ashore passes to the ComGenSIXTH Army upon his announcement to ComPhibsPac that he is ready to assume control of the forces ashore. ComGenSIXTH Army and ComPhibPac promptly report to CinCAFPac, CinCPac and ComFIFTH Fleet the time of assumption of control of forces ashore by ComGenSIXTH Army.
2) Nothing in this type procedure limits the two Commanders in Chief from exercising under their general responsibilities such controls as extraordinary or unforeseen circumstances may necessitate.
V. AREAS OF NAVAL RESPONSIBILITY
1) The division of Naval responsibility for the conduct of operations in the Combat Area is as follows:
a) Commander THIRD Fleet is responsible for the conduct of Naval operations in the Combat Area east of 135 degrees east. Commander MARIANAS Forces also has the responsibility for aerial offensive reconnaissance in this area, and he will coordinate such operations with the operations of Commander THIRD Fleet.