Operation NEPTUNE Joint Fire Plan, 8 April 1944

The air contribution to the Allied Joint Fire Plan for D-Day. Particularly notable is the great importance attached to operational security, the acknowledged difficulty of destroying the German defences from the air, and the decision to use the fighter-bombers as a reserve on 6 June, to reinforce success or respond to German reactions to the landings.

NJC/00/74/38

Dated 8 April 1944

‘NEPTUNE’

JOINT FIRE PLAN

OBJECT

1.  The object of the Joint Fire Plan is to lay down the general framework of the fire support programme for Operation NEPTUNE, as a basis for detailed instructions to be issued as necessary by the three Services.

PRINCIPLES

2.  The plan has been based on the following general principles:-

(a) The plan incorporates the air ‘cover’ action required in connection with the pre D Day bombing of batteries, and the air operations immediately prior to D Day designed to distract attention from the assault areas.

(b) First priority is given to the neutralisation or destruction of batteries that might interfere with the approach of the Naval Forces. For this reason the effort of the Heavy Night Bombers and Medium Oboe Bombers is allotted entirely to this type of target.

(c) The importance of neutralising the beach defences requires their engagement by air attack, though owing to their nature complete destruction is only likely to be achieved in a very small proportion of cases. The daylight bomber effort is accordingly allotted for attack against specific points in the beach defences, in the general ratio of 2:3 as between First United States Army and Second British Army respectively. For the purposes of preliminary planning each point will be allotted an equal weight of effort within each Army Sector. This allotment may require adjustment in the course of subsequent tactical planning.

(d) In order to ensure that the maximum forces are available on D Day, the effort employed during the days immediately preceding must be curtailed as necessary, so as not to prejudice the assault.

(e) Because of the prohibitive effort required to achieve destruction, the restricted number of AP bombs available, and the need for security reasons to include two batteries outside the NEPTUNE area for each one within it, the number of targets to be engaged prior to D Day has had to be restricted. With the exception of those batteries shown in Appendix ‘D’, specifically selected for neutralisation in the assault phase, attacks on batteries will be confined to those in open emplacements or under construction, with a view to harassing rather than destructive effect. Even in these categories the number that can be engaged will depend on the effort available and other commitments.

SELECTION OF TARGETS

3.  The detailed list of targets given in the Appendices to this Plan is subject to amendment in the light of general intelligence and the results of bombing prior to D Day. In view of the technical considerations, however, the earlier the programme can be finalised the better.

4.  The list of targets is subdivided as follows:-

Appendix ‘A’ - Batteries for air attack prior to D Day

Appendix ’B’ - Cover Plan targets for air attack immediately prior to D Day

Appendix ‘C’  - Targets for air attack on D – 1 day

Appendix ‘D’  - Batteries for attack by bombers prior to H hour

Appendix ‘E’  - Targets for naval bombardment

Appendix ‘F’ - Beach targets for daylight bombing during the assault

Appendix ‘G’  - Targets specially suitable for fighter bombers

NOTE: Beach Targets for bombardment by assault craft during the assault will be determined by the Assault Force commanders and Army Formation commanders

5.  Naval and Air bombardment timings for the assault are attached at Appendix ‘H’.

6. The question of pre-arranged targets for the first and subsequent turn round of aircraft is being considered separately.

Light Bombers

7.  The primary role of these squadrons will be the attack of suitable targets including road movement by night. The light bomber force, however, also constitutes a reserve available if necessary for use in the assault.

8. Two squadrons of Bostons will be held in readiness for possible employment of smoke laying in connection with the assault. In the event of these not being required for this purpose or conditions being unfavourable for their use in this role, they will be released as early as possible for other employment.

Fighter Bombers

9.  The main reserve in the initial stages of the assault will comprise fighter bombers.

Signed. CE Creasy, for Admiral, Allied Naval Commander, Expeditionary Force

Signed. FW de Guingand, Major General for General, Commander-in-Chief, 21 Army Group

Signed. HEP Wigglesworth, AVM for Air Chief Marshal, Allied Expeditionary Air Force