Air Power in the Normandy Campaign

A broad survey of the role of air power in the Normandy campaign, identifying some enduring themes in joint and coalition warfare.

 

Reference: RAF D-Day Brief

Reference: Operation Neptune Joint Fire Plan

Reference: Rommel on Air Power in Normandy

By the end of 1942, German forces were on the defensive after crushing defeats at Stalingrad in the Soviet Union and Alamein in Egypt. In January 1943, British and American leaders met at Casablanca in North Africa and determined a future strategy based on securing Germany’s unconditional surrender. In the west, this was to be achieved through three principal means. The first was the defeat of German and Italian forces in the Mediterranean, while the second was a sustained strategic bombing offensive against Germany to weaken her industrial capability and her will to fight. The third, scheduled for 1944, was an Allied landing in German-occupied Northern France. The landing became known as Operation Neptune, and Neptune’s target was to be the Calvados coast of Normandy, between the Cherbourg Peninsula and Le Havre.

Neptune was effectively the opening phase of Operation Overlord, the name assigned by the Western Allies to the broader Normandy campaign. Normandy was to provide a lodgement area to build up Allied strength and enable a break-out into Northern France and an advance towards the German frontier. In the ultimate achievement of this objective, air power played a critically important role. This essay surveys air operations in the Normandy campaign, and focuses particularly on the challenges raised by what has come to be known as ‘jointery’ – essentially the coordination of air,  land and maritime warfare in pursuit of Allied objectives.

Command and Control, and Targeting

Planning for Operation Overlord began in Britain in April 1943 under the temporary direction of the Chief of Staff to the Supreme Allied Commander (COSSAC); the Supreme Allied Commander himself had yet to be appointed at this stage. COSSAC was a joint organisation headed by a British Army general, Sir Frederick Morgan, and comprising planners from land, maritime and air forces, who brought together inputs from the individual armed services. COSSAC’s aim was to produce a plan whereby Allied forces would successfully land on the French coast and establish a lodgement area, which could be steadily reinforced, supplied and enlarged to secure a decisive military advantage over the German formations arrayed against them.

COSSAC’s thinking was heavily influenced by the disastrous Allied raid on the French Channel port of Dieppe in August 1942 – an operation which achieved none of its objectives and cost the Allies some 4,000 casualties. It was decided that the Normandy coast of France offered the best prospects of success for the landings, being less heavily defended than the Dieppe or Calais regions, but just near enough to Britain for continuous air cover to be maintained. 

By February 1944, the Allies were preparing to land on five beaches: the two westerly beaches, code-named Utah and Omaha, were allocated to American forces, while the three to the east, code-named Gold, Juno and Sword, were assigned to the British and the Canadians. Airborne troops were to be dropped on the eastern and western boundaries of the landing area to secure the flanks.[1]

Meanwhile, in December 1943, the Allies finalised their joint command and control structure for Overlord. The American general Dwight D. Eisenhower was appointed Supreme Allied Commander. Eisenhower had formerly commanded Allied forces in the Mediterranean; he was directly responsible to the Combined (US and British) Chiefs of Staff in Washington. His deputy was a Royal Air Force commander, Air Chief Marshal Tedder, who had similarly acted as Eisenhower’s deputy and air commander in the Mediterranean. Beneath them were three component commanders – General Montgomery (land), Admiral Ramsay (maritime) and Air Chief Marshal Leigh-Mallory (air).

Where the air forces were concerned, this was not a satisfactory arrangement. It arose because it was necessary (for planning purposes) for the Allies to appoint an air commander before Tedder returned to Britain from the Mediterranean. The Allies should simply have appointed a temporary air commander, who would have been relieved of his post as soon as Tedder became available. Instead, however, Leigh-Mallory continued to occupy his position and Tedder effectively became Supreme Commander for all air-related issues. It was often unclear where his authority ceased and Leigh-Mallory’s began.

Leigh-Mallory with Montgomery in Normandy

To make matters worse, Leigh-Mallory did not secure control of all air assets assigned to Overlord. The Americans disliked him intensely and were reluctant to allow their strategic bombing force (the Eighth Air Force) to be subordinated to British command. Ultimately, then, both Allied strategic bombing forces (the Eighth Air Force and RAF Bomber Command) were placed under Tedder’s direction on the strict understanding that he was acting on Eisenhower’s behalf.[2] Unity of command is one of the fundamental principles of warfare. For the Allied air forces committed to the Normandy campaign, it was not achieved.

A further weakness in the joint command chain concerned Montgomery’s position relative to the air and maritime commanders. Effectively, he was assigned the position of both land commander-in-chief and commander of deployed British and Canadian ground forces in Normandy. The Allied air and maritime command chains were different. They created a clear distinction between commanders-in-chief and commanders of deployed forces. Specific liaison channels were established between the tactical air forces destined for deployment to Normandy and the appropriate naval task force commanders.[3] But whereas Montgomery should have worked directly with the commander of the RAF’s Second Tactical Air Force, Air Marshal Coningham (and was repeatedly instructed to do so by Eisenhower and Tedder) he instead avoided Coningham and dealt mainly with Leigh-Mallory. After Overlord began, liaison between Montgomery’s and Coningham’s headquarters was largely conducted by their subordinates rather than by direct contact between the two commanders, who detested each other.[4]

Coningham, far left, well away from Montgomery
on the far right

Close relations between Air-Vice Marhsal Broadhurst (left) and
Lieutenant General Dempsey (right) helped make up for
friction between Montgomery and Coningham

Air Chief Marshal Leigh-Mallory’s formal title was Air Commander-in-Chief, Allied Expeditionary Air Force (AEAF). The forces at his disposal were the United States Army Air Force (USAAF) and the RAF air defence, ground-attack, tactical reconnaissance and air transport formations. He could act as advisor and co-ordinator for the strategic air forces, but not as their commander. The air plan drawn up by his staff was entirely designed to support the Allied naval and ground forces committed to Overlord. Six principal air tasks were identified: control of the air, air reconnaissance, interdiction and isolation of the battle area, air support for ground forces, operations against the German Navy, and air lift for the airborne forces.[5]

To fulfil this tasking, air operations were planned in four phases. The preliminary phase covered air operations that had been in progress for a considerable period before the spring of 1944, chiefly the Allied strategic bombing offensive against Germany, but also fighter sweeps and air reconnaissance over northern France. Strategic bombing placed a ceiling on the output of Germany’s war economy and diverted huge resources of manpower and equipment to her home air defences.[6] Most importantly, however, Germany’s day fighter force suffered devastating losses while attempting to protect vital installations from USAAF day raids in the first months of 1944.

Offensive fighter sweeps in the meantime forced the Germans to evacuate many airfields located in French coastal areas, which might have threatened the Normandy landing beaches. Air reconnaissance during the preliminary phase produced a massive quantity of imagery which was employed for air targeting purposes in the months before Overlord began.[7]

Air reconnaissance photograph of German strongpoints
Hillman and Morris, inland from Sword Beach

Ultra-low-level reconnaissance of German beach defences
showing the elaborate obstacles that would confront 
Allied landing craft 

The second phase of air operations was termed the preparatory phase and was directed more specifically at targets related to Overlord. The necessary targeting work originated largely at the air, land and maritime headquarters, but was both guided and co-ordinated by COSSAC. Subsequently, after Eisenhower’s appointment, overall co-ordination was provided by his headquarters, known as the Supreme Headquarters Allied Expeditionary Force (SHAEF), working closely with Leigh-Mallory’s air headquarters. Within the air headquarters, a new Bombing Committee comprising scientific and industrial experts as well as air force officers was created to consider how best Allied air power could be employed in support of Overlord.

The most important target identified by the Bombing Committee was the railway network in northern France. Germany’s extended supply lines to Normandy were critically dependent on the French railways; their destruction would obstruct the movement of supplies and reinforcements towards the landing area. The first strikes on railway targets by Allied strategic bombers began in March 1944. Other important targets were German coastal gun batteries, radar stations, and naval installations. Air reconnaissance was to be intensified to ensure that the Allies maintained an up-to-date intelligence picture of enemy dispositions and defensive preparations.[8]

Heavily bombed railway marshalling yards
in France, 1944

The preparatory phase operations raised a particular problem for the Allies: if confined to Normandy they would disclose to the Germans the proposed Allied landing area. The Allies therefore implemented one of the most elaborate operational deception plans ever devised. Known as Operation Fortitude, it was designed to reinforce German expectations that the landings would be staged in the Calais region of France. To sustain the deception, it was necessary for the Allied air forces to conduct operations on an immense scale in the Calais area; indeed, for every one air raid mounted in Normandy two were flown against targets in more northerly parts of France.[9]

The third phase of air operations was termed the assault phase and involved direct air support for Operation Overlord during the amphibious landings. Five main tasks were identified: protection of the amphibious landing force, neutralisation of coastal defences, protection of the landing beaches from enemy air attack, interdiction of enemy counter-attacks, and support to land forces in their advance from the beaches. The fourth phase, known as the follow-up phase, was less well defined than the earlier phases and was dependent on the development of operations in the landing area. It was nevertheless broadly expected to include the continued attrition of the Luftwaffe, interdiction of enemy reinforcements moving to Normandy, direct support for ground forces, air lift for further airborne operations, and air transport.

An essential element of this phase was the movement to Normandy at the earliest possible date of the RAF and USAAF tactical air forces. Operating from southern England, these formations would have been unable to remain airborne for very long over Normandy; moreover, their operations would have been jeopardised in the event of adverse weather in the English Channel area. Hence, it was vital to deploy both fighters and fighter-bombers into Normandy soon after the landings. For this purpose, the tactical air forces would depend on the rapid construction of forward airfields in the lodgement area, using deployable prefabricated equipment and components. The Allies planned to construct 27 such airfields in the first 24 days of Overlord.[10]

The construction of forward airfields in Normandy was a
vital part of the Allied air plan

 Logistics

The execution of air operations in support of Overlord involved a colossal effort by the Allied air forces. Between 1 April and 5 June 1944, they mounted nearly 200,000 sorties over northern France and released around 200,000 tons of bombs; 2,000 aircraft were lost in combat.[11] Operations of such intensity required massive logistical support derived from full-scale industrial mobilisation in both Britain and the US. In 1944 they produced in total 127,000 aircraft whereas Germany produced only 40,000; moreover, whereas Allied production included the output of thousands of offensive bombers and ground-attack aircraft, German production was predominantly focused on air defence fighters that would pose little threat to Allied ground forces in Normandy or to shipping in the English Channel.

Allied losses in north-west Europe were easily offset by new aircraft production, aircraft repair provisions, and extensive aircrew training programmes, whereas the Luftwaffe was unable to sustain the losses inflicted by USAAF long-range fighters in the early months of 1944, as we have seen. Consequently, by June, the Allied air forces based in Britain numbered 10,500 serviceable aircraft whereas in total the Germans possessed only 975 day combat aircraft in France, Holland and Belgium.[12]

Such enormous disparities in front-line strength and industrial production were apparent in the land and maritime environments too. Behind the statistics were two factors – the crippling losses suffered by German forces in the Soviet Union, and American manpower and industrial might. By 1944, the US war effort had reached its peak. The defeat of Germany’s submarine fleet allowed the almost unhindered movement of troops, equipment and supplies across the Atlantic to Britain – one and a half million personnel and nearly eight million tons of equipment by 6 June.[13] The prospective landings in Normandy also offered a substantial logistical advantage to the Allies: their supplies and reinforcements had only to be moved a short distance across the Channel from Britain to the landing area, under the protection of Allied air cover. By contrast, German forces would be fighting at the end of long-drawn-out supply lines that were extremely vulnerable to air interdiction.[14]

This is not to say that the Allies had no logistical problems to consider. In fact, two particular issues threatened the sustainability of Overlord. The first was the absence of a substantial port in the landing area. In selecting Normandy for the landings, the Allies deliberately avoided French Channel ports like Calais and Boulogne because they were very heavily defended. It was planned that the nearby harbour of Cherbourg should be captured by US forces soon after the landings, but the problem was otherwise to be solved through the provision of two artificial harbours, code-named ‘Mulberry’. Manufactured in Britain, their component structures were to be floated across the Channel and assembled off the Normandy coast – one in the British sector, one in the American sector.[15]

The Mulberry Harbour at Arromanches

Supplies being beached at Omaha late in June 1944

In the event, the Germans wrecked Cherbourg’s port facilities before they could be captured, and they remained unserviceable until late August 1944. The British Mulberry harbour functioned very effectively throughout Overlord, but the American harbour was destroyed by a storm in June. Consequently, the Allies were forced to land the bulk of their supplies directly on to the beaches. The build-up of supplies and reinforcements in Normandy was therefore slower than expected – a problem that would limit Allied offensive planning in late June and early July.[16]

The second threat to the sustainability of Overlord was the manpower situation in Britain. By June 1944, Britain had been at war for nearly five years and her manpower resources were stretched to the limit. She had in fact reached the point at which she could no longer maintain the output of her munitions industries and the front-line strength of her armed forces.[17] This implied not only some reduction in the scale of her war effort, but also an inability to absorb high casualties during the Normandy campaign. To prevail, it was therefore vitally important for the Allies to avoid static, attritional warfare. Instead, their aim was to fight a war of manoeuvre, exploiting highly mechanised land warfare supported by tactical air power to achieve a rapid breakout. For Montgomery the key to success lay in what he termed ‘the violence of our assault’ and ‘our great weight of supporting fire from the sea and the air’.

Armoured columns must penetrate deep inland, and quickly on D-Day … We must gain space rapidly … The land battle will be a terrific party and we will require the full support of the air all the time, and laid on quickly.[18]

Execution

An important feature of Allied air activity before Neptune was the adjustment of targeting priorities away from counter-air operations and towards interdiction and the isolation of the landing area. The establishment and maintenance of air superiority over France had initially been Leigh-Mallory’s key objective, but it became increasingly clear that US escort fighters had inflicted an irreversible defeat on the Luftwaffe earlier in the year. Allied attention therefore turned further towards other goals set for preparatory phase operations. Attacks on the railway network cut rail traffic in Northern France by 85 per cent between March and June 1944, leaving coastal areas accessible to road traffic alone. Bridges along the Seine and Loire rivers were destroyed to obstruct German troop movements towards Normandy.[19]

The German radar chain along the French coast was systematically targeted along with forward headquarters and intelligence facilities. All six of the long-range aircraft reporting stations south of Boulogne were destroyed before D-Day, and at least 15 other installations were rendered unserviceable. On 6 June, the German radar network could not provide any advance warning of the forthcoming assault. The German signals intelligence headquarters for Northwest France was destroyed by RAF bombers on the night of 3 June.

German early warning and intelligence sites in Northern
France were subjected to frequent air attacks

The Luftwaffe sought to increase air reconnaissance activity over southern Britain to observe Allied preparations, but the RAF’s fighter defences intercepted virtually all aircraft committed to these operations. The Germans were effectively blinded and were, at the same time, supplied with a stream of false intelligence reports asserting that Calais rather than Normandy was the intended Allied landing area. By contrast, Allied air reconnaissance activity over German-held territory was intensified; much of the imagery gathered was supplied directly to ground forces destined to land in Normandy on 6 June.[20]

Only one significant target category remained largely undamaged in the months before Overlord. Along the French coast, the Germans were constructing a network of fortifications known as the Atlantic Wall, designed to repel the Allied landings. The strongest of these defences comprised heavy gun batteries that were capable of posing a serious threat to the Allied invasion fleet. The batteries were small targets and were often well protected, well camouflaged and defended by anti-aircraft artillery. They could only be demolished by larger bombs released by heavy or medium bombers, but these aircraft were unable to achieve the necessary accuracy with a sufficiently large weight of bombs.

The Merville and Pointe du Hoc battieries; although both
were accurately bombed, no bombs penetrated the
concrete casemates housing the German guns

Allied air commanders understood this problem, but the land and maritime commanders nevertheless insisted that the batteries should be targeted. An enormous bombing effort was therefore expended against them; again, for every one battery targeted in Normandy, two were attacked in the Calais region. Yet few of their primary weapons were actually destroyed. Indeed, it was subsequently found that (on average) approximately 420 tons of bombs had been required to hit one gun and that 2,500 bombs had to be released to secure one strike within five yards of the target. Fortunately, on 6 June, a combination of air attack, naval bombardment and the action of Allied ground forces severely restricted the activities of the most threatening German gun batteries, and only four actually fired during the landings.[21]

On the night of 5/6 June three airborne divisions were infiltrated into Normandy to the east and west of the landing area. In the east, the majority of British airborne troops were accurately dropped, but the American landings in the west were inaccurate and widely dispersed. Nevertheless, both forces succeeded in securing their most important objectives.

On the morning of 6 June, the largest amphibious force ever assembled positioned itself off the Normandy coast. After an aerial and naval bombardment of the beaches, the assault began. In the eastern sector British and Canadian forces quickly secured their beach objectives, but the British failed to capture the city of Caen – a key target for the first day of the operation. To the west, US forces captured Utah beach with only light casualties, but suffered heavy losses at Omaha and advanced only a short distance inland. Nevertheless, Allied commanders considered the landings to have been very successful; overall casualties were far lower than expected, and the Germans were taken completely by surprise. By 10 June, the five separate landing forces had linked up and a single lodgement area had been established.

British gliders near Ranville shortly after D-Day

The British landings at Sword Beach

Colleville-Sur-Orne, inland from Sword Beach; craters
left by American bombs intended for the beach
defences are clearly visible.

Air support for the assault on 6 June can be considered under two headings – direct and indirect support. Direct support operations were not particularly successful. Poor visibility prevented Allied bombers from bombing four out of the five landing beaches accurately. The bomber crews were told to delay the release of their weapons to ensure that they did not hit the Allied landing forces, but the majority delayed too long and dropped their bombs well behind the German beach defences. At the same time, the uncertain situation on the beaches at first left little scope for the Allied tactical air forces to intervene, and there were hardly any requests for close air support from the ground troops.[22]

However, away from the beaches, the position was very different. The Allied air forces maintained absolute control of the air over Normandy and prevented all but the most limited and ineffective action by the Luftwaffe. RAF fighters and maritime aircraft, working closely with the Allied navies, blocked the movement of German naval craft towards Normandy from both the North Sea and the Atlantic. Later in the day, Allied tactical aircraft began to observe and attack German ground forces attempting to move towards the Normandy coast.[23]

The development of air operations after the landings did not entirely conform to earlier Allied expectations. The Luftwaffe proved completely unable to mount a sustained challenge to the RAF and the USAAF over Normandy and never presented a significant threat to Allied ground troops. The air battle that Leigh-Mallory had anticipated simply failed to materialise. In the meantime, German attempts to counter-attack into the landing area gave the Allied tactical air forces their first opportunity to influence hostilities decisively.

Two particular episodes may be cited. In the first, the Panzer Lehr division, advancing north towards the coast on 7 June, was exposed to a series of devastating air attacks that destroyed 90 tanks and supporting vehicles and prevented them from relieving forward units fighting near to the landing beaches.[24] Three days later, a vital German headquarters, Panzer Group West, which was responsible for planning another counter-attack, was located by Allied intelligence  at the village of La Caine and immediately attacked by RAF Typhoons and Mitchells. The headquarters was completely destroyed; the commanding general, Von Schweppenburg, was wounded, his entire staff was killed, and the planned counter-attack was subsequently cancelled.[25]

Daylight assembly or manoeuvre by
German forces in Normandy soon
proved extremely costly

La Caine after the RAF raid

Enlargement of the same image: the German
headquarters was in the largest and most
visible house in the village

Such unpleasant experiences quickly rendered open manoeuvre and counter-offensive action by substantial German forces impossible in daylight. The Germans responded by changing their tactics, adopting dispersed defensive dispositions, efficiently exploiting all available cover, and confining large-scale assembly and movement to the hours of darkness. Allied ground forces seeking to broaden the lodgement area encountered tenacious German opposition: British and Canadian forces were halted north of Caen throughout June; the Americans struggled in the small fields and hedgerows – the so-called ‘bocage’ country – of Western Normandy, which was far better suited to defensive than offensive warfare.

Bitter fighting resulted in casualty rates on both sides as high as the highest rates recorded on the western front in the First World War: by 30 June, the Allies had suffered 58,732 casualties since D-Day. This was precisely the situation that the British Army had hoped to avoid. Montgomery, as overall Allied land commander, became the target of mounting criticism. He, in turn, argued that Coningham’s Second Tactical Air Force was not being sufficiently co-operative. Allied tactical air power continued to inflict significant losses on the Germans but could not alone achieve a breakout.[26]

It had been expected that, after the landings, the Allied strategic bombing forces would maintain operations to isolate the Normandy area from German reinforcements and supplies. However, on 14 June, proposals were also put forward for using the bomber forces in direct support of ground troops. The idea, which originated with Leigh-Mallory and his staff, was to bomb clearly defined channels across German defensive lines through which Allied ground formations could advance.

Leigh-Mallory’s enthusiasm for the concept was to some extent politically motivated: he was keen to secure greater influence over the employment of the strategic bombing forces. He submitted his proposals directly to Montgomery and without reference to Tedder. Tedder, unhappy that Leigh-Mallory had exceeded his authority, then blocked the plan, arguing that that there were few suitable aiming points north of Caen and that it would be extremely difficult to co-ordinate the bombing effectively with the subsequent ground offensive.[27]

However, by the beginning of July, the British Army had made little further progress, and Eisenhower was desperate for a breakthrough. Thus, when Montgomery sought support from the strategic bombing forces for his next offensive north of Caen – Operation Charnwood – the Supreme Commander approved his request. On 7 July, some 467 heavy bombers of RAF Bomber Command dropped 2,300 tons of bombs into the Army’s selected target area. Much of northern Caen was destroyed and, although it was subsequently captured by British ground forces, their advance was impeded by huge bomb craters and piles of rubble. Nevertheless, broadly similar tactics were afterwards employed in a much larger operation – Operation Goodwood – mounted on 18 July, and in further British and Canadian offensives in August.

Northern Caen - devastated by Bomber Command on 7 July

The success of Leigh-Mallory’s concept depended in large part on German dispositions in the targeted areas. In the British and Canadian sectors, German defences were both deep and dispersed and were therefore very difficult to breach. Thus, while British armour at first made good progress east of Caen during Operation Goodwood, it was eventually halted by the deeper German defences, which had not been as heavily or accurately bombed as the forward positions.

In the American sector, however, German lines were thinner, and their troops were more vulnerably concentrated in forward locations. On 25 July, in Operation Cobra, a force of 1,490 heavy bombers of the Eighth Air Force delivered over 3,370 tons of bombs into a target area just west of St Lo, and there were further attacks by 350 medium bombers and 550 fighter-bombers. The Germans suffered more than 1,000 casualties, and a gap was effectively blown in their front line. After heavy fighting, American ground forces broke through and drove rapidly south.[28]

German tanks and other vehicles destroyed by the Eighth
Air Force at the start of Operation Cobra

With the battle area no longer static, the Germans were compelled to stage large-scale troop movements in daylight for the first time since mid-June. Consequently, they became more vulnerable to Allied tactical air power. Initially, under Hitler’s orders, they counter-attacked west at Mortain on 7 August, employing three armoured divisions in an attempt to halt the US advance. But repeated attacks by Allied fighter-bombers stopped the German offensive that afternoon, and they were unable to make any further progress.[29] Through the Mortain attack and Hitler’s subsequent insistence on further operations in the area, the Germans exposed themselves to potential envelopment by Canadian forces advancing from the north, and US forces turning their southern flank. On 8 August, Allied plans were changed accordingly, with the aim of trapping as many German troops as possible in Western Normandy.

On the 14th, Hitler finally permitted a withdrawal, but it was too late. To avoid being surrounded, the Germans were forced to conduct a desperate retreat south and east of Falaise. On 16 August, the RAF and USAAF ground-attack squadrons were presented with an incredible array of targets - thousands of German troops and vehicles moving in tight columns along a few narrow roads in a frantic bid to escape from the Allied pincers. There could only be one result. In the area between Failaise and the River Seine, battlefield investigators afterwards located more than 9,000 destroyed or abandoned German vehicles, including more than 500 tanks and self-propelled guns.

Killed, wounded and taken prisoner, the Germans lost approximately 50,000 troops. It was their worst single defeat since Stalingrad. The scale of their losses was such that they were unable to re-establish a defensive line in Northern France. Having won the Battle of Normandy, the Allies advanced rapidly north and east to the very frontiers of the Third Reich.[30]

German forces desperately trying to escape
encirclement in the Falaise Pocket

An enlargement of the same photograph

Destroyed German vehicles and equipment 
littering the Falaise Pocket

German vehicles became an easy target for Allied
fighter bombers

Air Power in Normandy: Some Familiar Themes

Numerous familiar themes can be identified in this broad survey of air power’s role in Normandy. Clearly, control of the air was fundamental to the Allies’ victory. It gave them a critical advantage over the Germans throughout the campaign, and in every aspect of it. Although air power could not alone deliver victory to the Allies, it ensured that they would not be defeated, preventing any effective counter-offensive action by significant numbers of enemy troops. On 10 June 1944, the commander of German forces in Normandy, Field Marshal Erwin Rommel, wrote that his primary disadvantage was

The immensely powerful, at times overwhelming, superiority of the enemy air force … The enemy has total command of the air over the battle area up to a point some 60 miles behind the front. During the day, practically our entire traffic – on roads, tracks and in open country – is pinned down by powerful fighter-bomber and bomber formations, with the result that the movement of our troops on the battlefield is almost completely paralysed, while the enemy can manoeuvre freely.[31]

In such circumstances, the German defeat could only be a matter of time.

From the German perspective, defeat clearly resulted from a failure to commit sufficient resources to air power. In the Second World War, Germany pursued a limited air strategy, in which the activities of her air force were largely subordinated to the requirements of her armies. By contrast, the Allies developed a general air strategy, in which air power was employed not only in the joint environment but as a strategic weapon as well. Consequently, while Germany maintained large, well equipped and very capable ground forces, the Luftwaffe was allowed to decline steadily as a fighting force relative to the RAF and the USAAF between 1940 and 1944.[32] And yet, without air cover, the formidable capability of the German land armies proved impossible to exploit. Indeed, even if the Germans had deployed more ground forces to Normandy, the outcome would probably not have been very different once the Allies had established their lodgement area. The decisive factor in the battle was air power.

Symbolic of Allied air supremacy, some of the best tanks
in the world - wrecked or abandoned in the Falaise Pocket

Second, to use Clausewitz’s well-known phrase, no battle plan survives contact with the enemy. In joint operations, air forces must be prepared to respond flexibly to developments in the land battle; flexibility is, after all, air power’s defining characteristic. In Normandy, the anticipated air battle with the Luftwaffe did not materialise, but Allied ground forces required more air support than originally expected to overcome German resistance, and air plans had to be adapted accordingly.

This led to one particularly radical departure in the application of offensive air power, when strategic bombers, designed primarily for use against large urban and industrial targets, were employed in direct support of Allied ground offensives. In the summer of 1944, there was no doctrine, training or experience which might have prepared the RAF or the USAAF for such operations, and the bombers were by no means perfect battlefield weapons. Yet the air forces accepted the task assigned to them, learnt lessons from early operations such as Charnwood and Goodwood, and ultimately played a vital role in the breakout from the lodgement area.

Third, it is often difficult to apply air power in close proximity to the land battle. In 1944, close air support techniques, tactics and procedures were developing only slowly. The majority of attacks executed by Allied tactical aircraft in Normandy involved interdiction or strikes on targets of opportunity – not close air support (i.e., air support directed by a forward air controller or a comparable controlling authority and closely integrated with ground operations). At the same time, strategic bombers were not always sufficiently accurate when used in direct support of ground forces, and sometimes missed key target areas or bombed friendly troops by mistake. In the summer of 1944, there was a vital role for air power to play in the land battle, but it was essential for both ground and air forces to understand the challenges involved and the commitment required in terms of training, exercises, and procurement.

Close air support was the most difficult offensive air role to perform effectively. Indeed, it was generally easier to apply air power away from the immediate battle area, where it could still exert a critical influence on the land battle. In Normandy, air power isolated the battlefield by destroying railways, bridges and road junctions, and by interdicting German troop movements and supplies from other regions. Yet such operations were rarely visible to land commanders, who thus often failed to appreciate either the effort involved or the results achieved.

Fourth, the potential for exploiting air power could be directly influenced by the course of the land battle. A static land situation produced fewer opportunities for exploiting tactical air power than a land campaign characterised by movement and manoeuvre. While a dynamic land battle might compel enemy forces to assemble or move in open areas, where they could easily be targeted from the air, a static situation allowed them to deploy with the specific goal of reducing their vulnerability to air attack.

Within a week of the Allied landings, it was proving difficult for Allied tactical aircraft to fulfil the offensive support role effectively. Indeed, according to one post-war study, German measures to thwart the fighter-bombers may have reduced the effects of Allied air attacks by as much as 75 per cent.[33] More favourable conditions for the Allies came only after the American breakout at the end of July, which once more compelled the Germans to conduct large-scale assembly and movement in daylight.

Fifth, air power had a significant role to play in guarding the security of land operation plans. It did so by ‘blinding’ the enemy – by targeting his early warning and intelligence-gathering facilities, and by preventing air reconnaissance. Air power could also make a major contribution to deception operations by striking targets away from the future battle area. In 1944, the Allied deception plan delayed the deployment of the German strategic reserve to Normandy and held numerous other divisions in the Calais area until it was too late for them to influence the fighting further south.[34]

Sixth, air power also played a key intelligence-gathering role. The Allies benefited from very much better intelligence than the Germans in the summer of 1944 and successfully exploited a variety of sources. High-grade signals intelligence (known as ‘Ultra’) provided a vital insight into the thinking and actions of the German high command, and much valuable information on German defensive preparations was also received from French resistance groups who were in contact with the British intelligence services. But the most important source of intelligence for the Allied ground forces that landed in Normandy was imagery gathered by reconnaissance aircraft, or mapping based on that imagery. A single RAF Field Photographic Section supplied more than 120,000 images to Allied ground forces in the two weeks before 6 June 1944.[35]

Finally, an especially fundamental lesson was that joint operations could be severely hampered by flawed command and control arrangements. For the Normandy campaign, the Allies created an irrational command structure: there were too many air commanders (two air commanders-in-chief instead of one), and, on the British side, there were not enough land commanders (a single officer serving as land commander-in-chief and deployed land force commander). This led to unnecessary friction at the air/land interface. Command and control was complicated further by personality clashes, especially between Montgomery and Coningham. Better results might well have been achieved by the establishment of a more rational command chain in which key positions were assigned to officers more capable of effective collaboration – assuming, of course, that such arrangements could have satisfied the political constraints and sensitivities that so frequently characterise joint and coalition warfare.

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Notes

[1] Carlo D’Este, Decision in Normandy (Penguin, London, 1994), pp.34-38.

[2] Vincent Orange, Tedder: Quietly in Command (Frank Cass, London, 2004), pp.249-255.

[3] Air Historical Branch narrative, The Liberation of North-West Europe, Vol. 3, The Landings in Normandy (unpublished official narrative), first draft, p.6(a), note 2.

[4] Vincent Orange, Coningham (Centre for Air Force History, Washington DC, 1992), pp.199, 205.

[5] Air Historical Branch narrative, The Liberation of North-West Europe, Vol. 3, The Landings in Normandy, p.12.

[6] RJ Overy, The Air War (Stein and Day, New York, 1981), pp.155-160.

[7] Air Historical Branch narrative, The Liberation of North-West Europe, Vol. 3, The Landings in Normandy, pp.13-14.

[8] Ibid., pp.14-14(a).

[9] Ellis, Victory in the West, Vol. 1, The Battle of Normandy, (HMSO, London, 1962), p.103; Michael Howard, British Intelligence in the Second World War, Vol. 5, Strategic Deception (HMSO, London, 1990), pp.128-129.

[10] Air Historical Branch narrative, The Liberation of North-West Europe, Vol. 3, The Landings in Normandy, pp.14(a)-15, 17-19.

[11] Hilary St George Saunders, The Royal Air Force 1939-45, Vol. 3, The Fight is Won (HMSO, London, 1975), p.101.

[12] Overy, The Air War, pp.97-100, 155, 192; Air Historical Branch narrative, The Liberation of North-West Europe, Vol. 3, The Landings in Normandy, Appendix I; Luftflotte 3 Order of Battle, 31 May 1944 (held at Air Historical Branch). The full German Order of Battle for Luftflotte 3 (France, Belgium and Holland) on 31 May 1944 including non-combat types and night-fighters numbered 1,339 aircraft; of these only 700 were serviceable.

[13] Ellis, Victory in the West, Vol. 1, The Battle of Normandy, pp.28-29.

[14] BH Liddell Hart (ed.), The Rommel Papers (Collins, London, 1953), pp.486-487.

[15] Ellis, Victory in the West, Vol. 1, The Battle of Normandy, pp.86-90.

[16] D’Este, Decision in Normandy, pp.230-231.

[17] HMD Parker, Manpower: A Study of Wartime Policy and Administration (HMSO, London, 1957), p.226.

[18] D’Este, Decision in Normandy, chapter 15, pp.78-81, 86.

[19] Air Historical Branch narrative, The Liberation of North-West Europe, Vol. 3, The Landings in Normandy, pp.22-29, 33.

[20] Ibid., pp.31-32, 34-35; Howard, British Intelligence in the Second World War, Vol. 5, Strategic Deception, chapter 6.

[21] Air Historical Branch narrative, The Liberation of North-West Europe, Vol. 3, The Landings in Normandy, pp.29-31.

[22] Air Publication 3235, The Second World War, 1939-1945, Royal Air Force: Air Support (unpublished official monograph), p.145.

[23] Saunders, The Royal Air Force 1939-45, Vol. 3, The Fight is Won, pp.112-113; Orange, Coningham, p.195.

[24] Interview with Generalleutnant Bayerlein, former commanding general, Panzer Lehr Division, by Dr Forrest Pogue, 5 June 1945, US Army Military History Institute; Liddell Hart (ed.), The Rommel Papers, p.483.

[25] Christopher Shores and Chris Thomas, 2^nd Tactical Air Force, Vol. 1, Spartan to Normandy, June 1943 to June 1944 (Air War Classics, Hersham, 2004), pp.148-149.

[26] D’Este, Decision in Normandy, pp.155-156, 259-261; Orange, Coningham, p.200.

[27] Orange, Tedder, p.266; Air Historical Branch narrative, The Liberation of North-West Europe, Vol. 4, The Break-Out and the Advance to the Lower Rhine, 12 June to 30 September 1944 (unpublished official narrative), first draft, p.4.

[28] Ian Gooderson, Air Power at the Battlefront: Allied Close Air Support in Europe, 1943-45 (Frank Cass, London, 1998), pp.133-136, 141-149.

[29] Ibid., pp.110-117.

[30] Air Publication 3235, The Second World War, 1939-1945, Royal Air Force: Air Support, pp.161-162; D’Este, Decision in Normandy, pp.424-425, 429, 432, 437-438.

[31] Liddell Hart (ed.), The Rommel Papers, pp.476-477.

[32] Overy, The Air War, pp.262-264.

[33] Paper by Arthur Davies entitled ‘Geographical Factors in the Invasion and Battle of Normandy’, no date, Liddell Hart Papers, King’s College, London.

[34] Howard, British intelligence in the Second World War, Vol. 5, Strategic Deception, pp.129-132, 185-195.

[35] Air Historical Branch narrative, The Liberation of North-West Europe, Vol. 3, The Landings in Normandy, p.35.