Engineers of Victory

by Paul Kennedy

  Harker flew the P-51 for the first time on April 30, 1942 (the Rolls-Royce archives have, happily, a photo of that very plane after he brought it back to base). It clearly puzzled him. It turned easily, never stalled, and was fine at low to medium altitudes. Aerodynamically it was superb, that is, it had very low drag, although neither he nor anyone else at the time could quite figure out why.g Harker’s report finished with a sentence that, though laconic, caught the attention of everyone who read it: “The point which strikes me is that with a powerful and good engine like the Merlin 61, its performance should be outstanding, as it is 35 m.p.h. faster than a Spitfire 5 at roughly the same power.”43 A few days later, a team of Rolls-Royce mechanics pulled out the Alison engine and carefully lowered a Merlin 61 into the front of the machine Harker had flown. As the sharp-eyed test pilot noted, the distance between the front edge of the cockpit and the nose of the P-51 chassis was the same as that on the latest Spitfire, so it was a perfect fit.

  At the same time, Rolls-Royce’s outstanding Polish mathematician turned performance engineer, Witold Challier, equipped with the comparative aerodynamic details of both planes, produced a chart suggesting that a Merlin-powered P-51 should be able to outperform the Spitfire at all levels up to 40,000 feet and reach the astounding speed of 432 mph. (All Challier’s calculations proved to be absolutely correct.) Both men, supported by the dynamic general manager of Rolls-Royce, E. W. Hives, began agitating for the new hybrid version as soon as possible.

  When this information got to the resourceful Freeman, he responded immediately. Although Fighter Command and Bomber Command wanted all the Merlin engines for their own projects, Freeman ordered the engine conversion on another five P-51s, directing that two of them be sent to Spaatz in the United States as soon as possible for USAAF testing. When Hives shortly afterward proposed the conversion of 250 aircraft, Freeman doubled it to 500. Freeman was swiftly in touch with the managers at Packard (who put one of their Merlins into a P-51, which by now had received its more familiar name, the Mustang); with the influential U.S. ambassador to Britain, John Winant; and with the well-connected assistant air attaché Thomas Hitchcock, a former Lafayette Escadrille flier and a great Rolls-Royce enthusiast who had family links to the White House. Freeman also started nudging Churchill to write to Roosevelt, since everyone in the United Kingdom realized that if this Anglo-American hybrid was to be produced speedily and in sufficient numbers to alter the aerial balance, it had to be done in American factories. It was like the cavity magnetron story all over again: Britain was industrially overstretched, but the United States still possessed enormous capacity for additional aircraft and engine production.

  Then, inexplicably to Freeman, the scheme foundered. Sheer obstructionism on the American side now slowed down the mass production of the Merlin-engine Mustang. In the United States there were genuine rival claims being made on resources, and it was always going to be hard to argue that the output of American aircraft already in production should be curtailed for an unknown and essentially foreign newcomer. There was continuous misunderstanding of Harker and Challier’s point that the P-51 was good at all altitudes, and certain area commanders kept insisting that the plane was to be used according to the original specifications as a low-altitude tactical fighter, in which capacity it was just one of many. Then there were USAAF leaders who could not accept any claims of the Mustang’s superiority because they were devoted to the P-38 Lightning and the P-47 Thunderbolts, both of which had well-tried combat records. There were also powerful objections in the air force’s procurement offices and among rival manufacturers. Freeman, who followed American production figures as anxiously as he did Britain’s own, was warned by Roosevelt’s personal and very Anglophilic advisor Harry Hopkins in September 1942 that the USAAF had on order no fewer than 2,500 P-40 Kittyhawks, 8,800 P-39 Airacobras, and 11,000 P-63 Kingcobras, all of them hopeless against the formidable Focke-Wulf 190 fighter that was beginning to dominate the European skies, but each of these underperforming aircraft had its own significant backers.44 Additionally, the Mustang surely needed further testing and improvements.

  This was all understandable, if regrettable. What was less understandable was the sheer, relentless anti-Britishness of key members of the all-powerful Air Production Board under the stiff-necked Major General Oliver Echols. Hopkins was only half joking when he told Freeman that many Americans believed they naturally flew better than the British and always built better planes than the British. Since the P-51 had been first ordered by the RAF, it had not gone through the normal American channels of engineering scrutiny, and many officers devoted to that system fed Echols disparaging details when they inspected some of the early models. Essentially, the attitude was “not invented here.”45 The attaché in London, Hitchcock, was particularly scathing about all this: “Sired by the English out of an American mother, the Mustang has had no parent in the Army Air Corps or at Wright Field to appreciate and push its good points.… [I]t does not satisfy important people on both sides of the Atlantic who seem more interested in pointing with pride to the development of a 100% national product than they are concerned with the very difficult problem of rapidly developing a fighter plane that will be superior to anything the Germans have.” The more restrained official historians merely point out that “the story of the P-51 came close to representing the costliest mistake made by the AAF in World War Two.”46

  At this stage, there was little more that Freeman or his business allies at Packard and North American could do. There was little more that even Churchill could do, though he again used every one of the “usual suspects” (Ambassador Winant, special envoy and later Churchill family member Averell Harriman, and Hopkins, plus his private messages to Roosevelt) to have Mustang production given priority. The push had to come from the USAAF itself. Eventually the air force did come around, for two reasons. The first was the Schweinfurt-Regensburg catastrophe of October 1943. Although the Air Force told the press that the lull in bombing Germany was simply due to the winter weather, as well as to a shift to bombing the Reich from newly acquired Italian airfields, both Arnold and Spaatz now privately recognized that their basic operational assumption was faulty: the bombers could not get through without fighter protection, and the existing fighters were too short-legged. By now, Arnold knew that even members of Congress were agitating. In his so-called Christmas address (given December 27, 1943) to air force commanders in Britain and Italy, Arnold gave out his bluntest message: “OVERLORD and ANVIL [a landing in the south of France] will not be possible unless the German Air Force is destroyed. Therefore my personal message to you—this is a MUST—is to ‘Destroy the Enemy Air Force wherever you find them, in the air, on the ground, and in the factories.’ ”47 But only an extremely nimble and long-range fighter, of a design recognized by Harker nineteen months earlier, could do that.

  The second reason was the continued pressure exerted by a small and remarkable cluster of individuals in the middle levels of the Allied effort. There was the irrepressible Tommy Hitchcock, who possessed the characteristics of an Ivy League playboy—he was acknowledged to be the world’s best polo player before the war—and, in addition, possessed a great flying record, a fluent pen, and a noted set of connections. Hitchcock was one of the few people who had no fear of browbeating Echols and the Air Production Board, or of privately approaching his neighbor Eleanor Roosevelt about the matter. Then there was the assistant secretary for air, Robert A. Lovett, who had flown in the legendary First Yale Unit in 1917–18 and in the Royal Navy Air Service, and would finally complete his public career as secretary of defense in the early 1950s. Lovett came from a patrician New England family, was not drawing a salary, and was much respected by Arnold. Like Hitchcock, he was not daunted by the Air Production Board and as early as 1940 had regarded the Alison-powered P-51 as a “washout.” Lovett carried out a major inspection of the USAAF bombing campaign during a June 1943 tour in England and made a number of recommendations in his report to Arnold, the tw
o most important of which were (1) the absolute necessity of increasing the production of auxiliary drop tanks as swiftly as possible, to enhance the range of all aircraft in Britain, and (2) the greater urgency that needed to be given to the development of long-range fighter escorts, with the Merlin-powered Mustang being particularly promising in this regard. These were the keys to unlocking the aerial deadlock. When Lovett returned to his office in Washington, by no coincidence right next door to Arnold’s, obstacles began to fall. Four days after reading this report, Arnold composed a memorandum that stressed “the absolute necessity for building a fighter plane that can go in and come out with the bombers.”48

  There was also strong pressure from air force officers stationed in England, including the irrepressible Major Donald Blakeslee, an American who had fought through the Battle of Britain with a Royal Canadian Air Force squadron, then, to avoid being appointed a training officer, switched into the volunteer American Eagles squadron. Blakeslee flew Spitfires and adored them, but he knew their limitations of range. When he flew the first RAF Mustangs, he agitated incessantly to have the fighter groups attached to the Eighth Army Air Force (based in eastern England) equipped with the same planes. When the pugnacious Lieutenant General Jimmy Doolittle was pulled back from the Mediterranean and put in charge of the Eighth, he immediately pressed for Mustang squadrons, and Arnold and Spaatz, now persuaded of their virtues, found them. Portal in turn ordered four RAF Mustang squadrons to fly with the Americans. All such squadrons from the Ninth were transferred northward and placed under Blakeslee’s boss, Major General William Kepner, the forceful head of the fighter groups. In fact, all USAAF pilots with any Mustang training were ordered to the Eighth. The logjam had broken, and not a moment too soon.

  Air Supremacy, at Last

  The air war in Europe was not, of course, transformed by a single “wonder weapon.” Rather, the crucial developments came about as a result of tactical, technical, and operational complementarities that, coming together after many setbacks, allowed a small group of British and American individuals to solve a problem that had plagued strategic bombing for many years: how to realize the early visions of weakening an enemy’s capacity to fight through the steady application of modern airpower.

  What was critical were the interactions and feedback loops: the impact of one operational failure or victory upon another, for example, or the changes a new weapon could bring about at the tactical level that in turn affected the larger outcome of battles.49 One such complementarity was mentioned earlier, namely, the fact that the RAF and USAAF bombed around the clock and thus gave the enemy little respite. Much more could have been done in this respect, and the Combined Chiefs of Staff repeatedly urged a greater integration of targeting, but the mere fact that British bombers flew over Germany each night and U.S. bombers did so each day placed enormous stress on the Reich’s defenses. Neither air force could claim that they did it alone.

  The other great complementarity was the use—perhaps a better word is placement—of the Mustang as a long-range daylight escort. It did not make redundant the Spitfires, Thunderbolts, and Lightnings, but augmented their efforts, especially at the greater flight distances. The tests by Rolls-Royce had shown that while the P-51 was considerably heavier than the Spitfire, it needed far fewer revs per minute to attain the same altitude and speed (this was the aerodynamic puzzle); it got to where it needed to go with much less effort. But there was another aspect to this aircraft that had intrigued Freeman, namely, its astounding fuel capacity, which when combined with its aerodynamic economy of consumption produced a miracle. “In terms of US gallons, its normal internal fuel tanks held 183 gallons (269 with a full rear tank) compared with 99 for the Spitfire, and it consumed an average of 64 gallons an hour compared with 144 for the P-38 and 140 for the P-47. With full internal tanks, including an 86 gallon rear fuselage tank, and two 108 gallon drop-tanks, its combat radius was 750 miles.”50 That must have been more than twice a Spitfire’s range.

  The drop tanks—the second enhancement pressed by Lovett after his visit, and being toyed with by most air forces by the middle of the war—were thus also a critical part of this tale, for while they were the factor that most enhanced the P-51’s range, they automatically gave every British and American fighter a much wider range. Once the full potential of drop tanks to increase an aircraft’s range was appreciated, everyone wanted them, not just the fighter squadrons. The British were so desperate for them that they manufactured a 108-gallon fuel tank out of stiffened paper; it was actually lighter and more capacious than the later U.S. metal versions, and was preferred by many American fliers, who scrounged batches of them. It also denied the enemy the reuse of the discarded aluminum casings.51 With attached drop tanks, all the Allied fighters—Spitfires, Lightnings, Thunderbolts, Mustangs—could fly farther and stay longer in the air.

  The newly equipped Allied strategic bombing campaign (called Operation Pointblank) resumed with a vengeance in early 1944, at last putting into practice its declared goal of the “progressive destruction and dislocation” of the enemy’s capacity to resist. The breakthrough was a consequence of the resumption of the USAAF’s daylight raids upon the great industries of the Third Reich, this time increasingly escorted by long-range fighters. It didn’t happen all at once, of course. The first Mustang squadron (Blakeslee’s) had joined the Eighth at the end of 1943, but there were never enough planes in the early raids, nor were the new Mustangs themselves free of imperfections. But the American war machine was now in full swing, and hundreds of Thunderbolts and Mustangs were arriving in the United Kingdom each week—transported on the decks of the escort carriers no longer needed for that role because of the U-boats’ setback—to join the hundreds of new Flying Fortress and Liberator bombers that were being flown overhead by the male and female shuttle crews of Allied Transport Command.

  INCREASING ESCORT FIGHTER RANGE

  Providing long-range fighter escorts in daytime for the American heavy bombers was the critical component in gaining air supremacy between 1943 and 1944.

  The breakthrough was the decimation of German fighter squadrons, and it worked in the following way. Spaatz stuck to specific strategic targets: Allied intelligence had identified Germany’s shrinking oil production as a key weakness and, slightly later, Eisenhower ordered concentrated bombing of the railway lines and bridges of most of western Europe as preparation for the D-Day landings. North German shipbuilding yards for U-boat construction were also on the short list. As the Americans recognized, such targets had to be defended by the Luftwaffe. But the new Allied long-range fighters could now neutralize Galland’s hitherto successful policy of waiting until the Allied bombers were unescorted. If Luftwaffe squadrons sought to disrupt the bombers before they reached the Rhine (which made a lot of sense), they would have to tangle with the advanced Spitfires and the remarkably tough Thunderbolts; if they waited until the aerial armadas were attacking key inland German industries, communications, and refineries, they would find Mustangs high above them, coming down out of the sun. More than that, Doolittle made the bold decision to release the Mustang squadrons from close escort duty to go hunt German fighters all over the skies, if necessary driving them down to ground level, where the Mustangs’ astonishing aerodynamics would prevail.

  The Americans lost heavily in the ferocious battles of that critical spring of 1944, and many of their best bomber and fighter pilots were killed, maimed, or captured by a desperate German resistance. But they always had reinforcing squadrons, while the Luftwaffe suffered a catastrophe from which it never recovered. To save the Reich, it pulled vast numbers of aircraft and crews from the Eastern Front, which gave the Soviet air force a major advantage in the advance on Germany. It also pulled most of its remaining squadrons from the Mediterranean. But it availed Goering nothing: seeing Mustangs flying in broad daylight over Berlin in mid-1944, he is reported to have said, “We have lost the war,” perhaps one of his few honest statements. By March of that same year Mustangs
were downing proportionately three to five times more German fighters than the more numerous Thunderbolts, although the latter were certainly inflicting their own heavy damage.52 And the giant British bombers still came during the night, intensifying the pressure upon Germany’s aerial defense systems.

  Around this time, in late spring 1944, the Luftwaffe cracked; its exhausted fighter pilots could take no more. “Monthly losses, which included most of the experienced German fighter pilots, averaged 450 in the first five months of 1944; by the end of May, 2,262 had been killed. By 24 May 1944, only 240 of Germany’s single-engine day fighters remained operational.”53 Actually, many more aircraft were in the pipeline, but their completion was hampered by disrupted communications, slowdowns in ball-bearing production, and completely inadequate fuel production. Above all, there was the loss of fighter pilots and crews. The newly trained men had far fewer hours of flying experience than their American and British equivalents, and suffered accordingly. Mustang pilots who chased their prey to the ground reported that many German planes were unable to avoid crashing into a pylon, a tree, or a high building. Even the finest German aces, perhaps softened by an easier tussle on the Eastern Front, met their match, great and revered names simply exploding into the sky. In March 1944 the Luftwaffe lost more than a dozen veterans of the air war, including two group commanders, one with 102 kills, the other with 161. They were irreplaceable. As the U.S. official history diplomatically acknowledges, the Luftwaffe was hurt more through these aerial battles than through even the most relentless and expensive daylight and nighttime bombing of aircraft factories.54