The Boeing B-29 would ultimately become an excellent bomber, the best heavy bomber of the war, in the opinions of many airmen and aviation writers. But throughout its development and the early part of its operational history, its crews had to contend with one terrible flaw—its Wright R-3350 engines. For much of the aeroplane’s operational span, wags referred to it as “three turning, one burning”, a moniker it had earned in flight testing.
The R-3350 was designed in 1937 and its initial testing greatly impressed the Army Air Corps, but it was still not in mass production by 1940 when many in Washington expected the United States to be at war in the near future. A sudden urgency on the part of the Army to complete the development and full-scale production of the powerplant, led to haste in the effort and some serious and persistent problems. Rushing the programme in the pressures of the pre-war period cost the lives of many airmen and threatened the success of the whole B-29 project. Boeing was caught up in a seemingly endless series of design changes on the bomber and had to concurrently cope with the continuing engine troubles.
Of primary concern to Boeing chief test pilot Edmund ‘Eddie’ Allen when he started the flight testing of the XB-29 in September 1942, were the engineering projections that the engines were likely to dangerously overheat after merely an hour or so of operation. But his impression of the aeroplane’s performance through the first eighteen hours of flight testing remained essentially favourable. On December 28th, however, Allen was forced to prematurely abort a test flight of the prototype when the number one engine caught fire.
Another engine fire occurred two days later during the initial test flight of the number two XB-29, which caused suspension of the flight testing until February 18th. Allen resumed flight testing that day and, tragically, experienced two in-flight engine fires on the second test aeroplane. Then, declaring an emergency, he tried to return to Boeing Field, but the raging fire burned through the wing. Allen, his entire eleven-man engineering flight crew, nineteen workers at the Frye Packing Plant near the airfield, and five firemen, died when the big plane fell on the packing plant after breaking up in the air.
At the Wright aero engine company, an intensive effort was under way to correct the problems with the R-3350. The engine fires persisted through 1943, causing the loss of nineteen early-production B-29s, before two new marks of the powerplant were introduced with modifications that did reduce the tendency of the engines to overheat, and the related fire incidents. The extent of such incidents was reduced but not eliminated.
Engine fires continued to occur together with mounting aircraft and crew losses. Wright engineers then designed new baffles to enhance engine cooling and this dramatically improved the reliability and safety of the aeroplane, an improvement critical to its eventual success in the strategic bombing campaign against Japan.
Theirs was one of the most demanding jobs of Mustang pilots in the Second World War. They flew the missions of the Very Long Range (VLR) fighter groups, the 15th, 21st and the 506th Fighter Groups of the U.S. Army Air Force’s VII Fighter Command, the ‘Sun Setters’. These trips primarily involved the escorting and protection of the B-29 heavy bombers in their attacks on Tokyo and more than fifty other Japanese target cities between April and August 1945. In addition to the escort role, they would later be assigned to hit ground targets including airfields, ship, road and rail traffic, and enemy facilities, in preparation for the long anticipated Allied invasion of the Japanese home islands.
Based on the hard-won island of Iwo Jima 650 miles south of Tokyo, the Japanese capital, the Sun Setters accompanied the American heavies fifty-one times on their exhausting visits to Japan and the Bonin Islands. Iwo Jima is a tiny island that is strategically located to provide both a base for the fighters that would protect the B-29s on their lengthy raids, and a sanctuary for the bombers that were damaged or short of fuel on their return flights to the Marianas. In the campaign, they engaged and destroyed 234 enemy aircraft in aerial combat and accounted for the destruction of a further 219 e/a on the ground. They suffered the loss of 99 pilots killed and 131 Mustangs shot down.
The P-51 Mustang was considered one of the most agile and manoeuvrable fighter planes of the war, but it did not handle nearly so well when full of fuel. It was equipped with internal fuel tanks in both wings, a fuselage tank behind the pilot’s seat, and a 110-gallon drop tank under each wing. While the fuselage fuel tank was still full, the aeroplane was tail-heavy and somewhat sluggish, and it was vital to burn off most of the fuel in this tank before taking on enemy aircraft in combat. It was also important to use the fuel of the drop tanks before entering air combat, as they would have to be jettisoned for best performance in action. The Mustang pilot then had to rely entirely on his remaining internal fuel supply for combat and his return flight to Iwo.
With its astonishingly great range, speed, reliability, fire power, and relative ease of maintenance, the Mustang proved the ideal fighter for this unique effort. These P-51s were, for the most part, flown by experienced combat pilots or men with many hundreds of hours as Mustang training instructors. They formed what they called ‘the Tokyo Club’, composed of P-51 pilots who had made the 1,300+ mile round-trip, frequently through rough weather, in their single-engined fighters to the enemy target cities that were fanatically defended by Japanese Imperial Air Force and Navy fighters. The Mustang pilots had to defend the bombers from the enemy aircraft, fighting their way to and from the targets, while occasionally suffering battle damage and always sweating out limited fuel, navigating across vast expanses of open sea, and the unimaginable fatigue of an eight-hour flight in a throbbing, roaring cockpit environment.
The contributions of the P-51 fighter and B-29 bomber to the successful conclusion of the Second World War for the Allies were immensely important. In the Pacific theatre of war, the Japanese continued to pursue victory at the end of 1944 despite the utter hopelessness of their military situation. Their military leaders determined to exact an enormous price in Allied lives and equipment by requiring their western enemies to mount and carry out a massive invasion of the Japanese islands rather than submit to the shame of surrendering on the Allies’ terms.
The American president Franklin D. Roosevelt had died in office on April 12th 1945, and Vice President Harry S. Truman, a then unknown quantity, took over the crucial U.S. war effort at a sensitive moment. One of his earliest briefings as president informed him of the existence of the American atomic bomb and its anticipated capability for the destruction of an entire major city. He was immediately thrust into decision-making about the possible use of the new weapon in the war. One consideration involved the pros and cons of invading the Japanese islands and the projected million or more Allied casualties. Should the Allies move ahead toward such an invasion? Should they instead try to bring about an end to the hostilities through the employment of the new and as yet untested atom bomb against one or more Japanese cities to force an unconditional surrender? Truman would soon have to decide.
In a commitment to President Roosevelt, his commander-in-chief, AAF General Henry H. Arnold had established the Twentieth Air Force to achieve “the earliest possible progressive destruction and dislocation of the Japanese military, industrial and economic systems and to undermine the morale of the Japanese people to a point where their capacity for war is decisively defeated.” In return, Arnold was given total control of the B-29s in the China-Burma-India Theatre of Operations.
In late August 1944, Major-General Curtis E. LeMay arrived in the CBI to take charge of XX Bomber Command, and later XXI Bomber Command, and the American bombing campaign against Japan. He had served in England where, as commander of the Third Bomb Division of the Eighth Air Force and had played a major role in the success of the daylight strategic bombing of Germany. From the new B-29 bases of Guam, Saipan, and Tinian in the Marianas island group, LeMay brought in a number procedural changes including target marking by Pathfinder aircraft, and other reforms. But B-29 crew and aircraft losses were rising in the high-altitude daylight attacks without producing the desired results.
Ultimately, LeMay concentrated all the B-29 operations against Japan in a series of ferocious fire raids that were even more extreme than the earlier fire-storm attacks on German target cities. The highly combustible wood and paper structures of Tokyo and the other Japanese cities and towns would prove optimal targets for his B-29s, which had sufficient “legs” and bomb-load capacity to bring enormous quantities of incendiary bombs over great ocean distances to hit Japan hard and often, and make her burn.
The first trial of LeMay’s fire raids on Japan occurred on the night of 9/10 March 1945, when 279 B-29 Superfortress bombers were dispatched to attack Tokyo. When the raid began, surface winds were gusting at 30 mph and the fires started by the thousands of incendiaries dropped from the bombers spread rapidly, creating the same sort of firestorm that had engulfed Hamburg in the British and American raids of July 1943. In this most destructive conventional air raid in history, sixteen square miles of Tokyo were destroyed and 84,000 people killed.
American Marines began an invasion of Japanese-held Iwo Jima on February 19th 1945, a bloody battle that would take thirty-six days and 6,821 American lives. The Americans had to deal with 23,000 Japanese defenders occupying the island. The airfields on Iwo were badly damaged and useless following the fighting. After the battle, U.S. construction battalions immediately began work there on an airfield for the P-51 Mustangs of the 15th and 21st Fighter Groups which would be assigned to the escort of the B-29s of XX Bomber Command. Iwo’s location enabled the round-trip to Tokyo for the Mustangs, but the volcanic dust of the airfield created problems with visibility in taxying and take-offs along with clogged filters in the planes.
In the night of March 27th, the pilots and enlisted men of VII Fighter Command on Iwo were awakened before dawn to small arms fire and screaming from Japanese hold-outs who had come down from their caves to infiltrate the American camp. With maniacal fervour, they used samurai swords to slash at the enemy tents, spreading confusion as the pilots scrambled for weapons to repel the attack. The combined Marine and Army Air Force personnel gradually eliminated the enemy resistance, killing 333 Japanese troops while losing forty-four Americans and suffering eighty- eight wounded.
The first mission in which the Mustangs shepherded the B-29s took place on April 7th, when 108 P-51Ds left Iwo to rendezvous with more than 100 of the big bombers at Kozu, heading for the Nakajima aircraft engine factory at Tokyo. Seventeen of the fighters were forced to abort the 1,320-mile mission. Navigation for the Mustang pilots was provided by three accompanying B-29s on both the entire outbound and inbound legs of the trip. These navigational bombers carried additional life rafts to be dropped to any Mustang pilot who might have to come down in the sea. The U.S. Navy also participated by positioning some of its submarines along the route of the Mustangs, ready to pick up any such unfortunate airmen.
Flying in a formation of staggered vees, the B-29s, which had come to be referred to as “B-san” or “Mr. B” by the Japanese citizenry, were protected by many flights of four Mustangs each which climbed to positions above and to the flanks of the bombers. From these positions the fighters began weaving to maintain pace with the bombers and to keep watch on each other’s tails in case any Japanese fighters should try to bounce them from above.
The B-29s were cruising at 15,000 feet, covered by the Mustangs which were staggered between 17,800 and 20,000 feet within ten minutes after rendezvousing with the bombers. As the formations crossed Sagami Bay between Atami and Hiratsuka, they were greeted by a profusion of Japanese fighters rushing to the attack. Tony’s, Tojos, Nicks, Irvings and Zekes arrived and tried to bore through the bomber stream.
At that moment, twenty P-51s of the 15th Fighter Group dropped their long-range fuel tanks and closed on the enemy aircraft, Major Gil Snipes in the lead. Dropping his tanks, Snipes experienced engine failure. His Mustang fell for nearly two minutes before he was able to restart the Merlin. He had lost several thousand feet of altitude and precious time while climbing back to the melee above. Rejoining his wingman, Snipes spotted and lined up on a pair of Tojos that were flying line abreast. Firing on one of the enemy planes, he saw it begin to trail smoke, but was rapidly overruning his victim and soon lost sight of him. But it was immediately replaced by another Tojo inviting his attentions. A quick burst caused the enemy plane to disintegrate, with the pilot managing to bail out.
As the giant American formation approached Tokyo, one of the B-29s was attacked by a twin-engined Japanese aircraft which dropped a phosphorous bomb on it. A Mustang attacked the enemy plane head-on, setting it alight and sending it downward.
As things so often happen in wartime, a foul-up occurred when Lt. Charles Heil lost contact with the three navigational B-29s and became separated from the other Mustangs of his squadron. He soon located and tacked on to another section of P-51s, not realizing that these fighters were, in fact, accompanying a different formation of bombers on their way to hit a target at Nagoya. When he believed they had reached the rendezvous point, he saw plenty of B-29s all around him, but no additional P-51s. Heil continued to fly with the bombers in the belief that they were headed for Tokyo.
As the whole force turned onto the bomb run, Heil’s engine began to misfire and he immediately contacted one of the nearby B-29s to inform the bomber pilot that he could not continue with them. The bomber crew then jettisoned its bomb load and turned back towards Iwo to shepherd the malfunctioning Mustang. The fighter and bomber made it safely back to Heil’s base, where he discovered that he had actually been to Nagoya instead of Tokyo.
In the Tokyo raid itself, the Mustang escorts shot down twenty-one Japanese fighters for the loss of one P-51. One other Mustang failed to return to Iwo Jima. Low on fuel 200 miles north of Iwo, the pilot, Lt. Frank Ayres, bailed out and was immediately picked up by a U.S. Navy destroyer. It would not be Lt. Ayres’ only contact with the American air-sea rescue operation.
Ayres was leading a flight of Mustangs on high cover over a fighter strike on June 23rd. The target was the airfield at Shimodate. Enemy aircraft rose to meet his flight and in the action, Lt. Ayres shot down one of them and turned to chase a second fighter down to 6,000 feet where he lost it in the clouds. He then encountered another enemy aircraft and his Mustang was damaged in the ensuing fight. He headed away from the target airfield, his engine shot up and his radio hit and unusable. He turned on a heading toward a point where he knew a U.S. submarine was on station to rescue downed Allied pilots. He located the position of the submarine and bailed out, landing in the sea within 100 yards of the sub. He was hauled on board before even having time to inflate his dinghy.
One of the Mustang pilots that day, Major James Tapp, was credited with the destruction of four enemy aircraft on the mission, and with damaging another. After his combats, he noticed a nearby B-29 that was obviously damaged and heading for the coast. It was being harassed by a Ki-43 Oscar, a slow and relatively fragile Japanese Army fighter, when Tapp intervened and soon shot the Oscar to pieces in a head-on pass. Tapp and his wingman then took on the job of protecting the crippled B-29, which was soon under attack again, this time by six assorted Japanese fighters. The Mustang pilots quickly broke up the party and shot a wing off one of the attackers. The bomber continued on to its base arriving there safely, if long overdue. At the giant B-29 base on Tinian island, there was elation among the American bomber crews over the success of their effort and, in particular, the difference made in their safety and survival by the presence of their greatly appreciated Mustang escort.
By May, the Mustangs of the 506th Fighter Group had joined those of the other two groups on the escort missions to Japan. The hazards of these operations was underscored for the American fighter pilots during the mission of June 1st. 148 Mustangs were climbing to join a large force of XXI Bomber Command B-29s on the way to a maximum effort attack on a target at Osaka.
Two hours into the flight the fighters entered an enormous weather front which towered beyond 23,000 feet. In the minimal visibility and violent turbulence, several mid-air collisions occurred, and many of the pilots became totally disoriented, their instruments toppling, their wings and control surfaces icing up. Strung out, with many of them lost, just twenty-seven of the original fighter force managed to locate and join up with the B-29 formation as it continued on course to Japan. More than ninety of the Mustangs were forced to abort and head back towards Iwo. Twenty-four of these simply disappeared and were not heard from again. Two of the fighter pilots bailed out when their aircraft ran out of fuel, but both were picked up by air-sea rescue ships.
In the weeks that followed, the Mustangs of VII Fighter Command performed brilliantly in the role of protecting the big B-29s to and from their Japanese targets, but, in the view of General LeMay, these high-altitude strikes were simply not producing results on the scale that was required. LeMay then elected to switch from daylight precision bombing with high-explosives from high altitude, to low-level night drops of incendiaries. The change was dramatic and profoundly successful, and also resulted in the re-assignment of the Mustangs to attacking Japanese airfields. They continued to engage many enemy fighters in the air near the fields, but also strafed, and rocketed many aircraft on the ground.
The final Mustang escort mission of the war was flown on August 10th 1945, the day after the second atomic bomb was exploded over Nagasaki, and four days after the first such weapon had been exploded over Hiroshima. On the U.S. escort mission to Tokyo of the 10th, P-51s of the 15th and 506th Fighter Groups downed six enemy aircraft. The protection provided by the Mustangs to the crews of the B-29s saved hundreds, possibly thousands of American airmen. Still, in spite of all the precision bombing strikes, the mining operations, and the massive fire raids, the unconditional surrender the Americans had been anticipating from the Japanese failed to materialise. In the end it took the devastation of two Japanese cities by B-29-delivered atomic bombs, and the threat of additional atom bombing, to bring Japanese officials to the peace table aboard the battleship USS Missouri in Tokyo harbour.