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Wednesday, October 26, 2016

The Argument Over the V-Weapons



By early 1943 enough evidence had accumulated in Britain of German secret weapon development to alert several of the responsible authorities to the danger of pilotless weapons – or other forms of long-range attack. The authorities included R.V. Jones, who advised the Secret Intelligence Service (MI6), as well as the Air Ministry, and who enjoyed the Prime Minister’s favour as the ‘man who broke the beams’, the Luftwaffe’s radio guidance system during the Blitz of 1940; Professor C. D. Ellis, the army’s scientific adviser; Dr A. D. Crew, Controller of Projectile Development at the Ministry of Supply, the British equivalent of Albert Speer’s Armaments Ministry in Germany; General Ismay, Churchill’s personal military staff officer; the Joint Intelligence SubCommittee, which co-ordinated the work of MI6, MI5 (the internal security service) and Special Operations Executive (SOE), Churchill’s subversive organisation overseas; and the government’s Scientific Advisory Committee. Too many fingers in the pie, no doubt; but the crucial initiates were Lord Cherwell (Professor F.A. Lindemann), Paymaster-General but holding that post as Churchill’s personal and long-time scientific adviser, and Duncan Sandys, since 20 April chairman of the committee, soon to be known as the Bodyline, then Crossbow Committee, charged with overall responsibility for investigation of the secret weapon threat.

Churchill believed in ‘creative tension’ as a principle of administrative efficiency, the fostering of rivalries between government servants to generate energy in the examination of problems and the keenest critical response. It was a sound principle, as long as normal personalities were involved. There was nothing normal about the personalities of Sandys and Cherwell, or in turn about their relationship with their overlord. Sandys was an ambitious young politician of grating disposition, who had a possessively filial attitude to the Prime Minister. Cherwell, a rich bachelor scientist of exceptional intelligence, also had a possessive attitude towards Churchill. Never quite at home in England, though he was a Fellow of the Royal Society, an Oxford professor and a resident of Devon, he seemed unable to shrug off his sense of foreignness, the product of German birth and education, burning British patriot though he was. He had attached himself to the Prime Minister during Churchill’s wilderness years, adulated him personally and jealously guarded his own status as the medium through whom Churchill received scientific advice. The appointment of Sandys to head the secret weapons committee touched him to the quick. Observers noted that – discreetly heterosexual though he undoubtedly was – he trembled with an almost feminine indignation at the slight. The regrettable outcome was that, because Sandys early espoused the idea that Nazi Germany was indeed developing a long-range rocket, Cherwell grasped at every strand of his extensive scientific knowledge to decry the thought: liquid fuel was unmanageable, only a solid-fuelled rocket would work, it would have to be a multi-stage monstrosity, its launch sites would be so large as to be undisguisable, it probably existed only in the minds of unreliable foreign agents. The idea, he argued in a phrase that inextinguishably attaches to his considered advice, was ‘a mare’s nest’.

The secret weapons intelligence plot, between the first deliberate overflying of Peenemünde by RAF photographic intelligence aircraft in April 1943 and the arrival of the first pilotless weapon on British soil on 13 June 1944 (a flying bomb, not a rocket), was therefore bedevilled at every turn by reasoned disagreement between the parties to the investigation. To his credit, Cherwell never dismissed the feasibility of a cruise missile (the flying bomb). Indeed, he argued that, if a pilotless weapon threat existed, it was probable that it would take a cruise missile form. Because, however, agents’ reports of the V-1 came later, while evidence of the rocket threat, however vague and misleading, came earlier and more plentifully, the British were both misled and caused to disagree among themselves. The disabling weakness of the German secret weapons programme was to attempt to do too much with too little; the British were further confused by the German investment in a multi-stage long-range gun (the ‘high-pressure pump’) and a rocket-propelled anti-aircraft missile, the Wasserfall (Waterfall). The weakness of the British intelligence counter-attack lay in an absence of practical knowledge of rocket or cruise missile technology and so a lack of clarity in their attempt to perceive what it was they were seeking to identify. The very wealth of intelligence received during April, May, June and July 1943 – from agents, prisoner-of-war interrogations and air photographs – required laborious analysis but in its diversity and imprecision provided something for anyone who had taken up an intellectual position on the nature of the threat or who denied its reality.

Among those contributing were a captured German tank technology officer who co-operated so enthusiastically with his interrogators that he was appointed a British civil servant and posted to the Ministry of Supply as ‘Mr Herbert’. He had information on anything he was asked about including, eventually, the German secret weapons programme. He claimed that he had been involved in the development of projectiles weighing a hundred tons, launched either from a tube or a ramp. A senior officer of the Luftwaffe experimental unit, captured in April, told of his superior, Colonel Rowehl, being summoned to see Hitler at Berchtesgaden to discuss the bombardment of Britain with rockets and jet-propelled aircraft in the coming summer. ‘Mr Herbert’, when re-interrogated, remembered that he had witnessed the launch of a sixty-ton rocket and knew of another of twenty-five tons. He mentioned the involvement of the Askania company and of Peenemünde, and other circumstantial facts, all later proved accurate. During 1–5 June, four reports were received in London that substantiated, in one way or another, information on hand. They mentioned Rechlin, the Luftwaffe experimental station, Usedom, the island on which Peenemünde was located, described it as a German army, not Luftwaffe, establishment (important, because the rocket was an army weapon) and, in the last report, described the firing of three rockets, 50–60 feet long, from ‘testing pit No. 7’. Large pits, clearly visible on air photographs of Peenemünde, had puzzled the interpreters. The reference was misleading, since the rockets were fired from transporter-erectors positioned in the open, but it seemed to emphasise that the British should be interested in Peenemünde.

This pot-pourri of information merely helped to harden attitudes among the investigators in Britain, not to elucidate. The positions were as follows: Duncan Sandys was fairly certain that the Germans were developing a rocket; R.V. Jones was uncertain but had an open mind; Lord Cherwell was absolutely convinced that a rocket was not technically feasible. His argument was fiercely reasonable: take-off would demand an enormous thrust; such thrust could only be supplied by an enormous charge of solid fuel inside a very large rocket; a very large rocket would need a conspicuous launch platform, either a ‘gun’ or a large ramp; no such structures had been identified; therefore the rocket did not exist. He dismissed the notion that the Germans might be using liquid fuel – he appears not to have studied Goddard’s pre-war experiments in America and to have been unaware of recent British experiments, conducted by Isaac Lubbeck for the Shell Petroleum Company – on the grounds that it would be impossible to control the flow of gases out of the rocket, which could not therefore be guided. Cherwell was to persist in this view until the contrary evidence became incontrovertible.

Meanwhile, photograph reconnaissance of ‘cylindrical’ or ‘torpedo-like’ objects at Peenemünde accumulated; interpretation suggested dimensions of ‘38 feet by eight [in diameter]’, ‘40 feet by 4 feet thick’, ‘35 feet long with a blunt point’ (we now know the warhead had not been fitted), ‘a cylinder tapered at one end and provided with 3 radial fins at the other’. On 23 June a photographic mission returned with film of two ‘torpedo-like’ objects, both thirty-eight feet long, six feet in diameter and with three fins. These photographs proved critical in advancing the debate about what Peenemünde threatened.

Sandys summarised the evidence in a report on 28 June. ‘The German long-range rocket has undoubtedly reached an advanced state of development . . . frequent firings are taking place at Peenemünde.’ Prisoner-of-war and agent reports implied a range of 130 miles, making it likely that it would be fired from the Pas de Calais, the part of northern France nearest London. Work of a suspicious nature – in fact the construction of a large concrete bunker – had been detected at Wissant. However, the report again grossly overestimated the rocket’s weight, at between sixty and a hundred tons, with a warhead of up to ten tons, and was still based on the suggestion that it was solid-fuelled.

That was unfortunate, given that so much of the assessment was correct, for the continual false judgement could only lend weight to Cherwell’s dismissal of such a monster rocket’s existence. On 29 June the Defence Committee (Operations) of the Cabinet met in Churchill’s underground command centre in Whitehall. Sandys and Cherwell were present, so was Jones, so were the Chiefs of Staff and the Prime Minister. The meeting opened with a presentation of the most recent Peenemünde photographs, described by Sandys as providing conclusive evidence of the rocket’s existence. Cherwell responded by raising again his technical doubts, his warning that the signs observed might be decoys, and concluded by suggesting that, if there were a secret weapon, it was probably a pilotless aircraft. Jones, asked by Churchill to comment, then disconcerted Cherwell by coming down on the side of Sandys. Thitherto he had harboured real doubts, reinforced by the deference he owed to Cherwell as one of his former Oxford pupils. Now he declared himself convinced that the rocket existed. Cherwell raised the final objection that, if so, the ‘flash’ of its launch must have been observed, say by Swedish fishermen in Baltic waters. Since there were no reports of ‘flash’, there could be no rocket. His objection, however, rested on his fixed belief that launch speed could only be achieved by the detonation of a large charge of cordite. The committee chose not to consider the question of whether the Germans might have overcome the difficulty of using liquid fuel. Instead it accepted the probable evidence of the rocket and made three decisions: to continue even more vigorously the examination by every means of the area of northern France within 130 miles of London; to attack rocket-launching sites in that area as soon as they were located; and to bomb Peenemünde.

The Peenemünde raid took place on the night of 17–18 August 1943. It was mounted by 433 Stirling, Halifax and Lancaster heavy bombers of RAF Bomber Command, while eight Mosquitoes staged a diversionary attack on Berlin. Earlier in the day the US Eighth Air Force had bombed Schweinfurt in southern Germany. The Germans were on the alert – a low-level British code they had cracked revealed that a night raid would take place – but they expected the target to be Bremen, another north German city, or Berlin. The sky was clear, though partly obscured by cloud over Peenemünde itself. Cloud would partially disrupt the British bombing pattern. The dropping of radar-confusing foil over Denmark by the Mosquitoes on their way to Berlin would distract the German night-fighter defence.

Soon after midnight, the Pathfinders of the RAF bomber force began dropping their indicators on Peenemünde. Some fell astray, with the result that the aiming point moved southward, away from the test area at the tip of the island. One effect of the misplaced indication was to direct heavy bombing on to the camp occupied by foreign workers, killing several hundred. Nevertheless, many hits were achieved on the laboratories, the rocket factory and the scientists’ housing estate. About 120 of the scientific and technical staff were killed. In the aftermath, it was decided to move the technical facilities to Kochel, in Bavaria - Peter Wegener was one of the scientists transplanted – and the manufacture of the A-4 (V-2) to a new underground Central Works in the Harz Mountains at Nordhausen. Nordhausen was to be built and operated largely by foreign labour; but the destruction of the camp at Peenemünde not only killed apparently all the foreign workers who had supplied London with secret-weapon intelligence – several were Luxemburgers – but also ended the comparatively free conditions which had allowed them to communicate with British intelligence. Nevertheless, A-4 intelligence was not completely ended. The firing range was transferred to Blizna, a remote village in southern Poland, at the confluence of the Bug and Vistula rivers, and Polish agents’ reports were to keep the Crossbow Committee, as the British committee tracking the pilotless weapons’ development was known, supplied with information in the coming months.

Meanwhile, perturbed by reports of ‘long-range guns’ and suggestions that mysterious buildings in both the Pas de Calais and the Cherbourg peninsula might be connected with the enemy’s secret weapons programme, the Allies were led to attack a conspicuous concrete building at Watten, in the Pas de Calais, on 27 August. It was almost completely devastated by the USAAF; later it was discovered to be a rocket store, not a launch site. Other sites, including a bunker at Siracourt and a ‘high-pressure pump gun’ battery at Mimoyecques, were to be destroyed by precision bombing in 1944.

Friday, August 5, 2016

MAP OF THE MONTH – Battle of Britain, 1940 – 41

MAP OF THE MONTH - Battle of Britain, 1940 - 41

Armchair General has partnered with The Map as History, a company that produces outstanding animated maps with accompanying narration. Each month, a link to one of their animated maps will be featured on the ACG site. This month's map explores the Battle of Britain and "the Blitz," Adolf Hitler's air war 1940-41 that was intended to bring Britain to its knees.

The Most Dangerous Enemy – Book Review

The Most Dangerous Enemy - Book Review

The Most Dangerous Enemy: An Illustrated History of the Battle of Britain. By Stephen Bungay. Zenith Press, 2010. 210 pages, hardcover. $40.00. For most British, the Battle of Britain holds a place of reverence similar to the esteem that many Americans have for defining moments of American history, such as the American War for Independence or the Alamo.

Monday, March 14, 2016

Great Britain-Royal Air Force

Very nice full set (50 cards) of British cigarette cards depicting “Aircraft Of The Royal Air Force”, issued in 1938.

The Royal Air Force (RAF) came into being in 1918 and was an independent force on an equal footing with the Royal Navy and the army. Its civilian head was the secretary of state for air, who presided over the Air Council. The top uniformed officer was the chief of the air staff. Until May 1940, there was also, on the Air Council, an air member for development and production, but this position was obviated by the creation of a separate Ministry of Air Production. In 1941, this ministry was reintegrated into the Air Council and was headed by the controller of research and development.

Operationally, the wartime RAF was divided into Bomber Command, Fighter Command, Coastal Command, Reserve Command, and Training Command. Training Command subsequently absorbed Reserve Command but was itself divided into Flying Training Command and Technical Training Command. Before the war ended, more commands were added: Army Co-Operation Command, Balloon Command, Maintenance Command, and Ferry Command (responsible for delivering aircraft from factories to combat units). In practice, Coastal Command was under the control of the Admiralty, and Fighter Command assumed control of all homeland air defense, including antiaircraft artillery. Each RAF command was organized into groups, which were in turn divided into squadrons. Fighter groups also featured a “fighter wing,” which was intermediated between the group and squadron level.

Bomber Command
True strategic bombing targets cities, but does so mainly to destroy industrial production and transportation networks, then only secondarily to terrorize the civilian population and undermine a nation’s will to continue to fight the war. Strategic bombing is a form of economic warfare, which directly attacks war production and other industrial and transportation enterprises. Among British as well as American air officers were many who believed that a large-scale program of strategic bombing could create a devastating and therefore decisive economic effect, including, ultimately, the complete destruction of the enemy’s war economy. Despite significant political resistance in Britain and the United States during the 1930s, advocates of strategic bombing managed to persuade their governments to fund the design and construction of heavy four-engine bombers (including, in Britain, the Wellington, Whitley, and Hampden; and in the United States, the B-17, B-24, and B-29), which were the necessary platforms from which heavy, long-range bombing could be executed.

The British conducted strategic bombing under cover of night. This had the advantage of making the bombers difficult to intercept with fighters or to hit with ground-based antiaircraft artillery. Early in the war, long-range fighters were unavailable to escort the bombers deep into enemy territory; this made the bombers especially vulnerable. Yet night bombing had the distinct disadvantage of rendering targets all but invisible; precision bombing was therefore out of the question; therefore, the British employed carpet- bombing (also called area-bombing) techniques. Instead of targeting particular industrial plants or transportation hubs, for example, the British would bomb an entire urban area, hoping to hit valuable industrial targets in the process. This was a highly destructive approach, but there was no guarantee that a raid would hit anything of real strategic value.

Fighter Command’s Finest Hour
After initial skirmishes over the Channel during July and early August, the battle of Britain began officially for the Luftwaffe on Adlertag (“Eagle Day”), or August 13, 1940, which commenced the protracted Operation ADLERANGRIFF (“Eagle Attack”). Although the fight in the sky was extremely dramatic at the time and in later recollection, at no point was the RAF on the verge of defeat. It lost many aircraft and good men in fighting over the south, but it was able to replace both without drawing down its main reserves by depleting the defense of the north of Britain. The fundamental problem for the Germans was a basic failure to understand that air warfare by its nature was attritional and therefore, that the RAF could not be eliminated in a single “decisive battle.” The Luftwaffe was also ill-equipped for the mission, with slow medium bombers with inadequate bomb loads and fighters escorts of still more limited range. That was true even though it had tried to develop a strategic bombing capacity before the war and had a significant lead in long-distance navigation and other blind-bombing aids.

There were several keys to the outcome. The RAF fighter force was larger than the Luftwaffe realized when the fight began, despite heavy losses over France and the Low Countries in May and June. Also, Britain was able to significantly outproduce Germany in fighter aircraft throughout the campaign: Luftwaffe intelligence calculated a fighter replacement rate of 180-300 per month, whereas the RAF actually achieved a rate of nearly 500 per month. The Wehrmacht held back resources from German fighter production, which underachieved its goal by 40 percent in the summer of 1940. The RAF thus readily replaced its aircraft losses where the Luftwaffe did not. Similar erroneous estimates of RAF losses marked incompetent Luftwaffe intelligence reports throughout the battle. Also, the fight took place over Britain. That meant the RAF recovered many downed pilots but the Luftwaffe lost aircraft and crews: nearly 1,400 aircraft all told and many crews killed, taken prisoner, or lost in the Channel. British training schemes were already operating at full tilt, whereas the Luftwaffe’s were not. The RAF therefore did not have to draw down main reserves from the center and north of the country without also replacing those more idle squadrons with fresh aircraft and pilots. Fighter Command was further aided by a series of bad decisions born of sheer Nazi arrogance and the erratic decision-making system in Germany. The most fateful of these was Hitler’s choice-provoked by rage over two small British raids against Berlin-to switch bomber targeting from RAF airfields to attacks on British cities. That caused many civilian deaths but allowed the RAF to continue to attrit German bombers and fighters alike. The fundamental reason for the German defeat was the fact that the Luftwaffe was asked to improvise a strategic air campaign for which it did not have the right planes or doctrine, against sophisticated British air and ground defenses in preparation over several years. Finally, the Luftwaffe had no precedent, let alone direct experience, in attacking an enemy that waited behind a comprehensive early warning radar system and had an excellent command-and-control radio net with which to direct fighter air defenses.

Coastal Command
From 1936 RAF Coastal Area operations were elevated to a full Coastal Command. The Royal Navy and RAF thereafter cooperated in coast watch, shipping defense, and anti-submarine warfare around Britain’s coasts and over the North Sea. In 1941 the Admiralty was given operational control of the aircraft of RAF Coastal Command, although its assets remained listed under the RAF order of battle. Through late 1940 the anti-submarine element of Coastal Command was limited by lack of “Sunderland” or other reconnaissance aircraft, and by a more urgent need to fl y invasion-watch missions. During 1941 longer-range aircraft were added, and anti-submarine reconnaissance was emphasized. There followed a growing role for older bombers in hunting and killing U-boats, as new four-engine heavy bomber types began to leave British factories and deploy over the continent. This led to serious interservice arguments: RAF Bomber Command’s Arthur Harris did not want heavy bombers used for defensive purposes. It required direct intervention by Prime Minister Winston Churchill in August 1942, to guarantee that the Royal Navy got the long-range reconnaissance aircraft and bombers it needed for its vital battle at sea.

Tactical Air Force
RAF units supported British and Allied ground and naval forces in all theaters in Africa and Europe. The Regia Aeronautica was blasted from the skies of East Africa by the RAF by the end of 1941. The Western Desert Air Force then established theater superiority over the Italian and German air forces in North Africa. Waves of RAF fighters strafed enemy ground forces by day, while tactical bombers struck troop and armor concentrations and supply points at night. Long-range indirection was carried out against deep rear targets such as supply depots and rail lines. Total victory was achieved early in 1943. Meanwhile, fighter defense of Malta survived heavy Axis assault to inflict devastating bomber losses on the Luftwaffe and catastrophic losses on all asset classes of the Regia Aeronautica. The campaign continued to Sicily and Italy in the second half of 1943. The RAF became highly tactically innovative as it applied lessons from North Africa that carried over to the fight in Italy, then France and Germany in 1944-1945. For instance, close support of ground forces was reduced in favor of winning the air battle at some remove; overall operations were directed from a single headquarters; actionable intelligence was closely integrated into air operations; and sophisticated control and communications systems were established between air and ground forces based on mobile radio transmitters carried in trucks that accompanied the troops and armor. Above all, as Richard Overy has noted, the RAF came to understand that maintaining air superiority meant continuous and unrelenting pursuit of the enemy. From these interservice lessons, and given its multinational cast, the RAF was able to fairly smoothly work out inter-Allied relations as larger American forces arrived in the ETO.

The RAF was supplemented by the Royal Auxiliary Air Force and the Royal Air Force Volunteer Reserve. Also, the air forces of the dominions, Australia, New Zealand, Canada, and South Africa, were incorporated into the RAF, as were elements of the air forces of nations that had been invaded and occupied by the Germans: Czechoslovakia, Belgium, Netherlands, France, Norway, and Poland. Although these elements were absorbed into the RAF, they were often permitted to retain their unique identity by forming into national legions or squadrons. Women also played a role in the RAF through the Women’s Auxiliary Air Force (WAAF) and Princess Mary’s RAF Nursing Service. The RAF drew many of its ground personnel, especially radar operators, plotters, and radio communications monitors, from the WAAF.

Air Transport Auxiliary (ATA)
A British volunteer aviation unit comprised mainly of civilian pilots. For reasons of age, gender, or health-there were several one-armed or one-eyed ATA pilots-these pilots were not draftable into active duty with the RAF. Although the ATA was administered and clerked by British Airways civilians, it was nonetheless put under command of the RAF, and its pilots were issued an RAF-style uniform. As military pilots were pulled from RAF ferry duties into combat, the ATA took up the load of flying urgent supplies within Britain, then the still more urgent business of ferrying aircraft from factories and storage facilities to forward air bases. ATA tasks included long-haul ferries of Lend-Lease aircraft manufactured in the United States and flown to the southern UK via Newfoundland, Iceland, and Scotland. Despite early RAF resistance to allowing women pilots into the ATA, a group of eight women began ferrying single-engine Tiger Moth trainers as early as November 1939-wartime necessity proved a partial gender equalizer. By the end of the war, 166 women pilots served in the ATA. They ferried all types of RAF aircraft during the war, including several Meteor jets. Twelve women qualified to fly four-engine heavy bombers, while 82 were certified on various medium bombers. Other women served as ATA grounds crew or mechanics. ATA male pilots ferried combat aircraft directly to bases in France from mid-1944. They were joined in that duty by female pilots from September. Civilian pilots of the ATA- representing 30 Allied nationalities-ferried 300,000 military aircraft by the end of the war.

The British army, navy, and air force all drew on conscription for personnel. However, all RAF aircrews were volunteers, many of them trained through the British Empire Air Training Scheme, in which the dominions participated extensively. Indeed, the time-consuming training of aircrews, especially pilots, was the chief factor limiting the effectiveness of the RAF-a far more limiting factor than aircraft production.

The RAF numbered 193,000 men at the outbreak of war in September 1939 and peaked at 992,000 in September 1944. The WAAF had 17,400 women in September 1940 and peaked at 180,300 in September 1943. RAF losses included 69,606 killed, 6,736 missing, 22,839 wounded, and 13,115 taken as prisoners of war.

List of Second World War Victoria Cross recipients

List of Victoria Cross recipients of the Royal Air Force

THE BATTLE OF BRITAIN – Strategic Thinking

Serious German aircraft losses from the spring campaign greatly weakened the Luftwaffe before the Battle of Britain. Had that been the only disadvantage under which the Luftwaffe operated, German strategic problems would have been daunting enough, given the difficulties of mounting a major combined arms operation. Unfortunately for the Germans, the strain that recent battles had imposed on their military structure represented only a small portion of the problem; a whole host of strategic, economic, tactical, and technological problems had to be faced and surmounted before the Reich could solve the “British question.”

What made an inherently complex task impossible was the overconfidence that marked the German leadership in the summer of 1940. Hitler, basking in a mood of preening self-adulation, went on vacation. During a visit to Paris after the signing of the armistice, tours of World War I battlefields, and picnics along the Rhine, the last thing on Hitler’s mind was grand strategy.” The high command structure, however, was such that without Hitler there was no one with either the drive or strategic vision to pick up the reins-a state of affairs precisely in accord with the Fuhrer’s wishes.

Until mid-July 1940, Hitler believed that England would sue for a peace that he would have happily extended to her. As early as May 20, Hitler had remarked that England could have peace for the asking. Nothing in British behavior in the late 1930’s suggested that Hitler’s expectation was unrealistic. In fact, there were still some within the British government who regarded Churchill’s intransigence with distaste. In late May, Lord Halifax, the Foreign Secretary, expressed his alarm at the relish with which Churchill approached his task, while “Rab” Butler, Under Secretary of State for Foreign Affairs, told the Swedish minister in London that “no opportunity would be neglected for concluding a compromise peace if the chance [were] offered on reasonable conditions .”

But the mood in Britain had changed. Churchill, furious at Butler’s indiscretion, passed along a biting note to Halifax. Butler’s whining reply that he had been misunderstood and had meant no offense indicates how much things had changed since Churchill had assumed power.” But one must stress that Churchill’s toughness as the nation’s leader reflected a new mood in Britain. In late June 1940, Admiral Dudley Pound told the French liaison officer at the Admiralty that “the one object we had in view was winning the war and that it was as essential for them [the French] as for us that we should do so. . . . All trivialities, such as questions of friendship and hurting people’s feeling, must be swept aside.” Indeed they were, when for strategic reasons, the British government ordered the Royal Navy to attack and sink the French fleet at Mers-el-Kebir.

The Germans missed the new British resolve almost completely, and Hitler’s strategic policy from the summer of 1940 through 1941 sought a method, whether it be military, diplomatic, or political, to persuade the British to make peace. The mood in Berlin was euphoric, since the Germans believed that the war was nearly over. All that remained, from their viewpoint, was to find the right formula for ending hostilities. Confirming this perspective was a strategic memorandum of late June in which Alfred Jodl, the number two man in the OKW, suggested that “the final victory of Germany over England is only a question of time.’ Jodl’s approach to the English “problem” reflected a general failing within the officer corps of all three services. As the campaign in the west in 1940 had shown, the tactical and operational performance of German military forces was without equal. The problem lay on a higher level: that of strategy. The Germans, if they had mastered the tactical and operational lessons of World War I, had not mastered the strategic lessons of that terrible conflict. While the French failure to learn from the last war had immediate consequences in May 1940, in the long run German unwillingness to face that war’s strategic lessons had an even more catastrophic impact on their history.

German strategic planning and discussions throughout the summer of 1940 reflect, in glaring fashion, a failure to grasp the essentials of strategy. The navy had squandered its battle cruiser assets in strategically meaningless operations off Norway in the late spring. The army drew up a plan for the proposed cross-channel invasion, code named “Sea Lion,” that one can charitably describe as irrelevant to and ignorant of the general state of available naval strength . The Luftwaffe throughout the summer, following Goring’s lead, paid minimal attention to the operational problems of a channel crossing by the army in the belief that its victory over the RAF would make an invasion unnecessary.
Jodl’s June memorandum posed two possibilities for German strategy against England: (a) “a direct attack on the English motherland; (b) an extension of the war to peripheral areas” such as the Mediterranean and trade routes. In the case of a direct strategy, there existed three avenues: (1) an offensive by air and sea against British shipping combined with air attacks against centers of industry; (2) terror attacks by air against population centers; and (3) finally, a landing operation aimed at occupying England. The precondition for German success, Jodl argued, must be the attainment of air superiority. Furthermore, attacks on British aircraft plants would insure that the RAF would not recover from its defeat. Interestingly, Jodl suggested that air superiority would lead to a diminishing capacity for the RAF bomber force to attack Germany. It is in this context that German attacks in the coming struggle on Bomber Command’s bases must be seen. By extending the air offensive to interdict imports and to the use of terror attacks against the British population (justified as reprisal attacks), Jodl believed that the Luftwaffe would break British willpower. He commented that German strategy would require a landing on the British coast only as the final blow (“Todesstoss”) to finish off an England that the Luftwaffe and navy had already defeated.

On June 30, 1940, Goring signed an operational directive for the air war against England. After redeployment of its units, the Luftwaffe would first attack the RAF, its ground support echelons, and its aircraft industry. Success of these attacks would create the conditions necessary for an assault on British imports and supplies, while at the same time protecting German industry. “As long as the enemy air force is not destroyed, it is the basic principle of the conduct of air war to attack the enemy air units at every possible favorable opportunity-by day and night, in the air, and on the ground-without regard for other missions.” What is apparent in early Luftwaffe studies is the fact that the German air force regarded the whole RAF as the opponent rather than just Fighter Command. Thus, the attacks on Bomber Command bases and other RAF installations partially reflected an effort to destroy the entire British air force rather than bad intelligence. Parenthetically, the losses in France directly influenced Goring’s thinking. He demanded that the Luftwaffe maintain its fighting strength as much as possible and not allow its personnel and materiel to be diminished because of overcommitments.

In retrospect, the task facing the Germans in the summer of 1940 was beyond their capabilities. Even disregarding the gaps in interservice cooperation-a must in any combined operations-the force structure, training, and doctrine of the three services were not capable of solving the problem of invading the British Isles. The Norwegian campaign had virtually eliminated the Kriegsmarine as a viable naval force. Thus, there were neither heavy units nor light craft available to protect amphibious forces crossing the Channel. The lack of escorting forces would have made “Sea Lion” particularly hazardous because it meant that the Germans possessed no support against British destroyer attacks coming up or down the Channel. The Admiralty had stationed 4 destroyer flotillas (approximately 36 destroyers) in the immediate vicinity of the threatened invasion area, and additional forces of cruisers, destroyers, and battleships were available from the Home Fleet.” Even with air superiority, it is doubtful whether the Luftwaffe could have prevented some British destroyers from getting in among the amphibious forces; the Navy certainly could not. The landing craft that circumstances forced the Germans to choose, Rhine River barges, indicates the haphazard nature of the undertaking as well as the tenuous links to supplies and reinforcements that the Germans would have had across the Channel. Just a few British destroyers among the slow moving transport vessels would have caused havoc.

Air superiority itself represented a most difficult task, given Luftwaffe strength and aircraft capabilities. Somewhat ironically, the strategic problem confronting the Germans in the summer of 1940 represented in microcosm that facing Allied air forces in 1943. Because of the Bf 109’s limited range, German bombers could only strike southern England where fighter protection could hold the loss rate down to acceptable levels. This state of affairs allowed the RAF a substantial portion of the country as a sanctuary where it could establish and control an air reserve and where British industrial power, particularly in the Birmingham-Liverpool area, could maintain production largely undisturbed. Moreover, the limited range of German fighter cover allowed the British one option that they never had to exercise: Should the pressure on Fighter Command become too great, they could withdraw their fighters north of London to refit and reorganize; then when the Germans launched “Sea Lion,” they could resume the struggle. Thus in the final analysis, the Luftwaffe could only impose on Fighter Command a rate of attrition that its commanders would accept. The Germans were never in a position to attack the RAF over the full length and breadth of its domain. Similarly in 1943, Allied fighters could only grapple with the Germans up to a line approximately along the Rhine. On the other side of the line, the Luftwaffe could impose an unacceptable loss rate on Allied bombers. Not until Allied fighters could range over the entire length and breadth of Nazi Germany could Allied air forces win air superiority over the continent.

LINK

Friday, January 1, 2016

An analysis of late propeller era combat aircraft



Back in the early 30's bombers were still crude: The were meant to take off, cruise, drop bombs, cruise possibly fend of fighter with machine guns and land. This was quite the same approach as in the First World War. In fact, night bombing (which happened to small extent in WW1) was included, but not exactly popular due to poor accuracy. This dominant bomber concept was so crude that Ju 52/3m passenger aircraft were adaptable as auxiliary bombers.

This primitive model of a bomber was shaken in the 30's by two new concepts; the dive bomber (for better accuracy of bomb drops; notably the Ju 87) and the fast bomber (for avoiding fighters; notably the early Blenheim, early Do 17 and SB-2).



Tupolev SB-2. Skin by Karel Chvojka, 3dz by Captain Kurt mod. by Karel C.

The machine gun defence proved to be unsatisfactory. It was difficult to add more defensive machine guns, while fighters increased their weaponry from two to up to eight machine guns. Armour plating, armoured windshields and self-sealing fuel tanks plus the increasing strength of airframes reduced the effectiveness of normal machine guns. Fighters were able to cope by adding 20 mm autocannons, while the same calibre was very unwieldy in movable installations for bomber defences.

Bombers needed better survivability than armour and machine guns could afford. Four approaches promised relief; flying higher, flying faster, flying in darkness and flying with escort fighters.

To fly higher was no good solution (for bombers) because of the inherent accident and reliability issues (due to freezing temperature), added aircraft cost, low payload and poor accuracy of bombing runs.

To fly faster was a questionable solution (for bombers) because it was a time of rapid improvements of top speeds in aviation. A bomber prototype could easily fly faster than all contemporary fighters and still find itself to be much slower than hostile fighters during a war only a few years later. The Mosquito was later on successful with this approach, but only so because it faced opposing forces that were limited in their performance (especially at high altitude) in part by an inferior raw materials base. Propeller aircraft were also bound to meet the limit of their potential at about 800 km/h, and without the introduction of turbine engines we'd have seen an air war scenario in which almost all aircraft would have had a very similar top speed again (as they had already in WW1).
To fly in darkness meant high training and avionics costs, a high accident rate and a typically poor accuracy.

To fly with escort fighters proved to be most successful, but that wasn't about bomber design itself.

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Reconnaissance aircraft of the late 30's looked still a lot like First World War reconnaissance aircraft, but they had badly fallen behind fighters in both cruise and top speed. The Hs 126 is a typical example. The poor survivability of such recce aircraft called for new approaches.

One approach was to fly higher - this proved less problematic for (photo) reconnaissance than for bombing, and the Ju 86P was one of the extreme examples.

Another approach was to fly faster, and this worked for recce better than for bombing simply because air forces needed fewer recce aircraft and the fast fighters could be adapted to photo reconnaissance. The Spitfire PR versions are a good example, also the F-4/-5/-6 U.S.A.A.F. aircraft and the Bf 109 and Fw 190 with recce kit (a specific "Rüstsatz"; mission module). There were also successful two-engined reconnaissance aircraft and even some dedicated fast photo recce aircraft.




The highly successful Japanese Mitsubishi Ki-46 III high speed photo reconnaissance aircraft

To fly in darkness proved to be a niche escape, for both illumination/flash bombs and infrared photography were apparently not fully satisfactory.

To fly with escort fighters - a typical WW1 approach - was unsuccessful because it was both uneconomical and because the ground control for interceptors enabled the defenders to face such a recce package with altitude and numerical superiority just about every time. This in combination with the fact that a single recce aircraft suffices to make photos while a single bomber doesn't suffice to bomb a target properly defined the recce aircraft as unique. They were usually alone on their missions. This influenced which survivability strategies did work and which didn't.

A unique alternative for battlefield recce aircraft was to fly too slow. Fighter had advanced in top speed at the cost of aerodynamics that led to a high stall speed. The Fi 156 was very successful as a short range battlefield reconnaissance aircraft in part because even fighter aces had difficulties to get a Fi 156 into their crosshairs if they managed to do it at all. It was just too damn slow and agile. The same effect was observed in trial mock dogfights against Fl 282 helicopters. Very slow recce aircraft were only suitable for very short range aerial recce and very vulnerable to anti-air weapons, though.

The next analysis is about fighters. There were basically two directions for fighter philosophies in the 30's; the manoeuvrability school (Italians, Japanese, Czechs) that emphasised dogfights and even aerobatics (overall a similar philosophy as in WW1 air combat) and the high speed school (Germany) that emphasised a superior speed. The Russians initially followed both schools with their I-16 (fast monoplane) and I-153 (more agile biplane).

The high speed school was typically combined with low drag liquid cooled engines that were less powerful than radial engines (during the 30's) and did thus initially lack a superiority in climb rate over the more agile fighter designs. Liquid-cooled engines caught up with radials when radials grew to the limits of single radials (the solution was the double radial engine, but that brought cooling issues) at the end of the 30's. By 1939/1940, both liquid and air cooled engines were at about 1,000 to 1,300 hp. By this time liquid cooled engine-driven fighters had caught up with comparable radial-driven fighters in climb rate.

The whole competition changed during WW2. The high manoeuvrability school lost out in Europe; faster fighters were dominant because they chose when to fight and only they were able to cope with fast bombers. The Japanese stuck to the manoeuvrability school with few exceptions, Italy did too (and failed for several reasons) and the British did at least keep a better manoeuvrability than Bf 109 fighters.

The new conflict was different than the 1930's conflict between fighter philosophy schools: All fighters had to have a similar top speed to be competitive, but they proved to have different manoeuvrability strengths.

The vertical air combat manoeuvrability school emphasized climbing and diving and in some cases also a high roll rate. The horizontal air combat manoeuvrability school emphasized tight turns and a low stall speed. The vertical school won, as evidenced by the Fw 190's success over Spitfires and the 1943-1945 success of U.S. fighters against most Japanese fighters. The reason was simple; the vertical school was again dominant, for it was the key to offensive manoeuvres. The horizontal manoeuvring was only at its premium in defensive manoeuvring and at very low altitudes.

Vertical air combat manoeuvre example: A Bf 109 expert vs. defensive fighter ring

To fly tight turns was mostly about shaking off a pursuing fighter (and had little chance of success if employed offensively), while climbing and diving was mostly about attacking a fighter (often with the deadly advantage of surprise). Defence may be stronger than offence most of the time, but offence is decisive. The vertical air combat manoeuvrability school was furthermore still potent in numerical inferiority situations.

Another division between fighters was between fighters for high altitude and for low altitude. Eastern Front and Pacific air wars were mostly about low altitudes, while Western European air combat was mostly about high altitudes. There was a spiral for ever greater practical flight ceilings whenever high altitude combat became dominant in a theatre. The Allies won this race in 1942-1944 thanks to the British lead in two-stage superchargers and the American ability to supply the necessary heat-resistant alloys for turbochargers. The Germans trailed in both regards, but jumped far ahead in 1944 with turbojet engines (even though they lacked heat-resistant alloys and had a very short lifespan, poor reliability and handling characteristics).

It's also possible to divide between short range and long range fighters; long range was important for escort fighters and over the vast expanses of the Pacific theatre, while short range was sufficient for interceptors and fighters supporting ground warfare.

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The post-WW2 period saw competing philosophies for fighters as well:

# Short range ("WVR") vs long range ("BVR") air combat
# Short range fighters vs. long range fighters
# high performance vs. huge numbers
# pursuit of superior speed and altitude performance after the first Mach 2 generation (mostly MiG-25, later F-22)
# low visibility to sensors ("stealth") vs. much external hardware
# avionics with finesse vs. brute power avionics (example for the latter: MiG-25 radar)

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It's interesting stuff (to me), but I'm not so sure about the lessons.
Aircraft kept becoming more capable, more refined, more oriented at their purpose.
There's an eternal development for better survivability.
Superior offensive qualities tend to dominate over the superior defensive qualities in air combat.

Sven  Ortmann of Defense-and-Freedom Blog