As a successor to the Hurricane, Hawkers had designed the Typhoon around the massive 24-cylinder Napier Sabre engine. The new fighter had a troubled gestation; engine and structural failures were all too frequent events. Although designed as a high-speed fighter, it lacked manoeuvrability, performance fell off with altitude, and at high speeds it became nose-heavy. In consequence, it was relegated to the close air support role.
The concept that low-flying attacks led to unsustainable casualty rates appears to have become something of an article of faith within the RAF in the interwar period. It was highlighted by Brooke-Popham, who in a lecture to the RAF Staff College in 1924, used the Battle of Amiens to argue that close support with low-flying attacks could not be maintained for more than a few days and was unlikely to be worth the cost, particularly if it compromised air superiority. Likewise, in 1934 the fears associated with low flying were being repeated by the RAF instructor at the Army Staff College in Camberley, Wing Commander John Slessor. Although he highlighted the potential efficacy of low-flying attacks on ‘third rate’ troops, he again used the example of Amiens, alongside that of Cambrai, to suggest that the cost against a capable enemy would make the task untenable.
Unfortunately, by extending the fairly specific evidence of casualty rates at Amiens, particularly those of 8 August, into deductions with more universal applicability, the Air Staff appear to have been selective in their analysis. Their suggestion that low-level attacks were uniformly costly, is not wholly supported by key contemporary documents and nor did they analyse the relative novelty of close support in August 1918. It was not acknowledged that low-level attack in the fluid offensive conditions at Amiens was still an unusual skill for the pilots involved. 8 Squadron had only been operating with the Tank Corps since 1 July 1918, and 73 Squadron was ordered to specialize in this role only after the battle. Had the Air Staff taken the time to analyse air support between 9 August and 11 November 1918, the RAF in general, and these Squadrons in particular, became vastly more effective. On 8 August the ten Squadrons of 22nd Wing flew 261 sorties in support of Fourth Army, dropping 703 25 lb bombs and firing 65,860 rounds of ammunition at ground targets. In the process they suffered 24 casualties of which at least 17 were shot down. The following day 238 sorties were launched dropping 860 bombs and firing 56,290 rounds. This time only 3 aircraft were lost. This dramatic reduction in casualty rates continued through 10 and 11 August where 8 and 5 casualties were sustained from 331 and 282 sorties respectively. This improvement continued into the latter stages of the war as on 10 October, the Wing flew 147 sorties, dropped 458 bombs and fired 39,970 rounds at ground targets without losing an aircraft. The pilots of 22nd Wing clearly learnt from their previous mistakes.
The improvement in performance was even more marked in 8 and 73 Squadrons. Aircraft from these units now refrained from flying indiscriminately at low level in the dangerous airspace over the battlefront, and began to concentrate their efforts on areas where anti-tank defences could be expected to exist. This change in policy seems to have brought about a marked reduction in the number of casualties suffered. At the Battle of Albert, between 22 and 25 August 1918, 8 Squadron dropped 132 bombs and sustained 1 casualty, while 73 Squadron cut its teeth in the close support role by dropping 24 bombs and firing 8,850 rounds of ammunition at ground targets without a single casualty. Furthermore, 73 Squadron is recorded as having given highly effective support to tank units at Ramicourt and Montbrehain on 2–3 October 1918, dropping 94 bombs and firing 7,100 rounds with one wounded pilot being the only casualty. Indeed, from around 1,000 sorties by 8 Squadron aircraft between 8 August and 11 November, a mere five were listed as missing. In contrast, 107 Squadron lost five aircraft from 15 sorties when intercepted by German fighters over the Somme on the morning of 9 August 1918. Whatever the perceived dangers associated with close air support, in the skies over the Western Front there were clearly more dangerous roles.
By misinterpreting the casualty data from low-level attack it would appear that the Air Staff were guilty of the subjective misuse of the evidence of Amiens which created a false perspective of the facts. This may have been inadvertent but in the debate over support to the Army, the RAF was the clear beneficiary. This also contradicts David Hall’s belief that the General Staff were to blame for the deterioration in inter-Service relations and the development of tactical airpower; the Air Staff played an equal role at least.
As a consequence of this doctrinal evolution, by the late 1930s the senior echelons of RAF leadership were so far removed from the concept of close support to the Army on the battlefield that they lost the capability in any meaningful sense, particularly with respect to training. As early as 1928 RAF reports were highlighting the fact that fighter squadrons were to be primarily trained to obtain air superiority rather than participate in the ground battle and discouraged ground attack training for the coming year. Although an exceptional exercise was conducted with the Army in 1938 the conclusions it drew were vague and sometimes contradictory. In 1939, while briefing 1 (Bomber) Group for their training support task to the Army, Air Commodore Willock, DSD RAF, stated that, ‘[w]hat we want to avoid above all for the Army to think that air forces should be diverted from their normal functions or that the potentialities of low flying aircraft should lead to their misuse’. His suggestion that any such aspirations may have resulted in some ‘confused thinking’ at the War Office may have been correct in certain aspects, but the War Office did not have a monopoly on this vice; the Air Ministry could be equally indulgent. As well as minimizing the necessary training, the Air Staffs lack of appetite for close air support also undermined the requirement for any specialist aircraft. When proposals to this effect were made in 1935 they were rejected by the Air Staff on the grounds that such aircraft were, ‘. . .neither in the role of the RAF in war, nor its “imperial police” duties in normal times . . .’ despite Deputy Director Plans, Group Captain Arthur Harris, observing, ‘. . . we shall undoubtedly in the future on occasion wish to exploit this form of attack and there is a danger that this requirement may be overlooked . . .’. Without the necessary training or specialist equipment, by 1939 close air support was truly moribund in the RAF.
Despite being partly used to justify the drift away from the task of close air support during the interwar period, consideration of the Battle of Amiens also played a major role in reintegrating the air and land battles through the concept of air interdiction. The key personality in this respect was Slessor. During his time as an instructor at Staff College, in addition to the dangers associated with close air support, he pointed out the potential for air power to influence the land battle by cutting enemy lines of communication in order to isolate the battlefield, the task we now term Air Interdiction. The concepts he developed were refined and eventually published in 1936 in his key book, Air Power and Armies. In this he concluded that an enemy’s critical vulnerability were his transportation systems in general and his railways in particular. The integrated nature of the railway systems suggested to Slessor that an attack at one point could have a consequence hundreds of miles away due to resultant congestion and delays. This effect became particularly pronounced at junctions where the delays could be simultaneously transmitted along several lines and hinder the use of alternative routes.
Slessor illustrated his conclusions on air interdiction with a lengthy examination of the Battle of Amiens in which he was as excoriating in his criticism of the conduct of the deep battle as he was of close support. Although acknowledging that elements of the air plan were intended to isolate the battlefield, he was extremely deprecating of the attempts to destroy the Somme bridges. In his opinion, not only was this difficult to achieve, it would not realize the desired effect and was therefore a waste of time and resources. In his opinion, far more utility could have been gained by attacking the key rail junctions at Cambrai, Le Cateau, Le Nouvion, Vervins and Laon. By assuming that Rawlinson intended to conduct a deep operation, Slessor suggested that after the successful ‘break in’ battle, Fourth Army was brought to a halt in by the arrival of 16 German divisions from their strategic reserves. Six of these divisions came from Armies on the northern flank of the German Second Army and passed through the key rail junction of Cambrai over a 48 hour period. Had they been prevented in so doing Slessor concluded that the Second Army would have been hard-pressed to reform an effective defensive line. His vision made its way into official doctrine in both the Air Force and Army operational manuals in the run up to the Second World War. In both the 1932 and 1938 editions of the War Office Manual, ‘The Employment of Air Forces with the Army in the Field’ (EAF) and the 1935 edition of AP1300, RAF War Manual Pt1 – Operations, advice was given that that the most appropriate target set for bombers employed in support of the Army was the transport system of the enemy.
What Slessor did not consider however was timing of the arrival of these reinforcements and how they influenced the development of the battle. The German troops defeated on the first day were already in place and those defeated on the second day deployed by foot or road vehicle. Only in the evening of 9 August did the Fourth Army run into troops deployed by rail. By this time Fourth Army’s artillery target intelligence was greatly reduced from the outset of the battle and very few tanks remained combat ready; the Fourth Army had already shot its bolt.
The Battle of Amiens had a baleful effect on the delivery of an integrated Air-Land battle in the interwar period. Subjective analysis of the close air support delivered by the RAF enabled the Air Staff to overestimate the cost of close air support missions and by extension threaten its ability to attain air superiority. This in turn generated the institutional view that fighters should not be used in the close support role except in dire emergency. Concurrently, doctrinal thought was shifting the efforts of the bombers from attacks on the battlefield to the enemy rear area. Consequently there was little appetite for the task for close air support to troops in contact and little training was conducted. Crucially, this undermined the development of the necessary capability to conduct or control such missions, even if the RAF subsequently chose to do so. Not without reason did an RAF officer point out that in the interwar period, ‘. . . the RAF forgot how to support the Army’.
The dysfunctional outlook of the Air Staff in the interwar period had a catastrophic impact on the ability of the RAF to contribute effectively to a land campaign at the outbreak of hostilities. By focussing its fighters on the battle to achieve air superiority it significantly degraded its ability to attack ground targets. Consequently, this task fell to its bomber units which would be forced to survive due to luck rather than judgement if heavy defences existed. This lethal shortcoming was cruelly exposed by the German invasion of France and the Low Countries in May 1940.
Although the rumbling debate over a separate air arm for the Army was reignited by the decision to commit the Army to the Continent in February 1939, the squadrons that deployed to France at the outbreak of hostilities remained firmly under command of the RAF. Although originally deployed in two elements, the Advanced Air Striking Force (AASF) and the Air Component in support of the Army, they were soon unified under Air Marshal Barratt as the British Air Forces in France (BAFF), consisting of 14 squadrons of medium bombers, five and a half fighter squadrons and four reconnaissance squadrons. Unfortunately however, alongside their French allies they were significantly weaker both in quantity and quality than the Luftwaffe, containing many obsolete aircraft. The Nazi invasion on 10 May 1940 pitched these forces into battle and immediately they were found wanting with the crucial engagements taking place over the Meuse crossings.
Following XIX Panzer Corps’ establishment of crossing points over the Meuse on 14 May, BAFF joined the French Air Force in attempting to cut the pontoon bridges over which Guderian’s troops were trying to deploy. The attacks were disastrous. The 109 British and 43 French bombers supported by 250 fighters, faced 300 German fighters and 303 anti-aircraft guns concentrated over and around the vital bridges. Although the raids rolled on throughout the day, the largest took place between 16.00 and 17.00 hrs when 71 Battle and Blenheim bombers hurled themselves into the fray. Stripped of their weak fighter escort by the German fighters, those flights that got through were hacked apart by the German anti-aircraft gunners. Of the 71 sorties flown, 40 aircraft were shot down; a loss rate that remains the RAFs highest for a comparable mission.
It is of interest to note what may have happened had the RAF’s priorities been different. Notwithstanding the additional four fighter squadrons sent to France at the advent of the German assault, 43 remained in the United Kingdom on strategic defence duties. Had a larger proportion of these been deployed to the Continent and been committed to the battle over Sedan, it is not beyond the bounds of possibility that air parity and maybe even limited superiority may have been gained. XIX Panzer Corps completed its bridges with the ‘last yard of available pontoon equipment’. If these had been hit no other equipment was immediately available. The ensuing delay would have brought the German tempo in line with that of the French and enmeshed them in a damaging and potentially fatal battle on the river. The consequences of such a battle will remain in the realm of counter factual speculation, however, as Kershaw has pointed out, support for the Nazi party was to a large extent built on the delivery of stunning and cheap victories that swayed the less belligerent elements of the German population; defeats could have easily taken them in the opposite direction. At the very least, a stalemated Western Front would have denied the Germans the advanced airfields necessary for their single-seat fighters to participate in the Battle of Britain.
Throughout the next two years the War Office continued to agitate for its own resources and the Air Ministry continued to resist. The impasse was broken in the summer of 1942 when two remarkably similar papers were drafted. The first, drafted by the War Office forwarded the suggestion that a new organization, the Army Air Support Group (AAS Gp), be formed consisting of fighters, bombers and reconnaissance aircraft. The intent of the proposal was not dismissed out of hand by the Air Ministry, although they felt unable to give assent to the detail on the grounds that it included permanent decentralization. Instead, they produced a paper of their own written by Slessor that proposed the creation of a similar mixed force to the War Office paper, except this force was to be formed from the existing RAF Fighter, Bomber and Army Co-operation Commands and placed under command of the RAF. Despite a last twitch of resistance from the War Office, the Slessor Plan reflected the advances that had been made in the Desert Air Force that had recently defeated Rommel at El Alamein. Buoyed by this associated success, it received support from Churchill and in early 1943 the Tactical Air Force (TAF) was born.
The TAFs that were prepared for the re-entry into Europe were essential in enabling the RAF and their allies to implement the doctrines of interdiction outlined by Slessor in the 1930s. Equipped with new medium bomber aircraft such as the Boston and Mitchell, and rugged fighter bombers such as the Typhoon, the TAFs possessed the means to strike powerfully at the enemy both at the battlefront and the lines of communication leading to it. However, the path towards interdiction was not always smooth and required assistance from Slessor himself to clear the final obstacles.
Slessor moved to the Mediterranean theatre as Deputy Commander of the Mediterranean Allied Air Forces (MAAF) on 14 January 1944. On arrival he found a debate raging and how the campaign in Italy could be best supported from the air. Slessor conducted a review which articulated for the first time an integrated campaign between the Mediterranean Allied Strategic Air Force (MASAF) and the Mediterranean Allied Tactical Air Force (MATAF). Alongside its strategic role against Germany, the MASAF was to attack the rail network north of the Pisa-Rimini line. South of that line the railways were to come under attack from the MATAF.
In what came to be known as Operation STRANGLE, the medium bombers of the MATAF targeted the marshalling yards while the fighter bombers targeted rail lines and bridges. As a consequence of this assault, by 4 April only 1,357 tons out of the requirement for 2,261 tons per day was getting through to the German front line. Although this campaign was unable to totally isolate the Germans in the Gustav Line, it made the maintenance of their position virtually untenable. As a result, in contrast to the failed ground attacks in February and March, the DIADEM offensive in May shattered the German Tenth Army.
In North West Europe, the air campaign in support of OVERLORD mirrored that in the Mediterranean. The former CO of 8 Squadron, Leigh-Mallory was by this time in command of the Allied Expeditionary Air Force which included the 2nd TAF. In the build up to D-Day, an acrimonious debate broke out between Leigh-Mallory and the strategic air chiefs, Harris and Spaatz over nature of the planned assault. Whereas Harris and Spaatz saw their main effort as the POINTBLANK campaign against strategic targets in Germany, Leigh-Mallory wished to see them utilized against the transport network leading into Normandy. Experience gained in Italy ensured that the debate was decided in favour of Leigh-Mallory. The campaign that followed was perhaps the epitome of an integrated Air-Land battle to date. While Bomber Command and the US VIII Air Force struck at key rail hubs in Western Europe, the final 2 weeks leading up to D-Day saw an intense assault by 2nd TAF and the US IX TAF to isolate the Normandy battlefield. By 5 June all bridges over the Seine downstream from Paris had been cut and such damage done that the German authorities considered the western rail network, ‘. . . to be completely wrecked’. Nor did the attacks stop on 6 June. The Panzer Lehr Division, in an echo of 119th Division’s experience on the Amiens-Roye road in 1918, described the road north from Vire as ‘fighter-bomber racecourse’ as it came under sustained air attacks losing over 80 combat vehicles in the process. The experience of Panzer Lehr became the norm for the German Armies in Europe from the spring of 1944 until the end of the War. Under savage assaults from the Allied tactical airpower they were never able to concentrate sufficient combat power to mount a realistic challenge to the Allied ground forces and those that they did were destroyed piecemeal.
The application of tactical airpower in Europe between 1943 and 1945 has been the subject of a detailed study by Ian Gooderson. He noted with interest the balance between 2nd TAFs conduct of close air support and interdiction in the guise of ‘armed reconnaissance’. His research indicates that armed reconnaissance was by far the more dangerous of the tasks and suggests that mutual support available from ground forces was partly responsible. This is a valid point and may point to the reason why 8 and 73 Squadrons had such low casualty rates in late summer 1918.
In conclusion we can see that the Battle of Amiens played a pivotal role in the development of British Air-Land battle capability between 1918 and 1945 as it provided the ‘evidence’ which at first separated the RAF from the ground battle before generating its renaissance in a different form. Whereas the response to high casualty levels during the First World War had been to create specialist units in the close air support role and improve command and control measures, the bitter debates in the interwar period had seen this skill wither on the vine. Parsimonious budget allocations exacerbated tensions between the Services. These resulted in acrimonious debates that became increasingly focussed on the sterile issue of command and control of the Air-Land battle rather than its successful prosecution. Rather than produce an objective study of combat experience, the RAF took a subjective view of the losses sustained at Amiens in order to reject participation in the land battle as a profitable task. This took such a deep-rooted hold that the RAF failed to train or equip its personnel for a role that was immediately required once the decision was taken to deploy forces to the Continent in 1939. Notwithstanding the wider shortcomings of the land campaign, the ensuing disaster in 1940 found much at fault in the Air Ministry in the preceding two decades. However, the lessons drawn from the Battle of Amiens also laid the foundations for the rediscovery of Air-Land battle in the latter part of the war. Although the redevelopment of the command and control, and TAF ‘hardware’, took place independently, the doctrine of air interdiction was rooted in the 1930s analysis of the air battle over Amiens. This provided the final piece in the combat system with which the British and their Western Allies battered the Axis forces into defeat in 1945 and which could trace its heritage to the battlefields of Amiens in 1918.