How the Allies Bombed the German War Machine

During World War II, the Allies launched the Combined Bomber Offensive (CBO), a round-the-clock strategic bombing campaign aimed at crippling Germany’s war-making capacity and achieving air supremacy before the D-Day invasion. Beginning in 1943, American bombers carried out precision attacks by day on factories, railyards, fuel depots and other industrial sites, while Britain and its Commonwealth forces struck German cities by night to break the will of the people.

Over the course of the campaign, the Allies dropped an estimated 2.5 million tons of high explosives, according to the U.S. War Department’s 1947 Strategic Bombing Survey. By the end of the war, the effort resulted in the destruction of an estimated 57,000 enemy aircraft and caused massive disruption to industry, transportation and communication systems, as well as untold suffering to Axis workers.

Victory came at a massive cost. “More than 26,000 died with the U.S. 8th Air Force, which had one of the highest casualty rates in the American military,” says historian Stephen Harding, author of the 2019 book Escape From Paris, which chronicles the air war over Europe. “That was more than the Marines suffered in the Pacific during all of World War II. The Royal Air Force, which had been fighting since 1939, lost some 55,000 men.”

Believing strategic bombing alone could defeat Germany without the need for costly ground offensives, American military planners began launching air missions over Europe in early 1942 using the Norden M-9 Bombsight, a new technology designed to improve bombing accuracy. Leadership believed that by flying in tight formations of heavily armed Boeing B-17s and Consolidated B-24s, the bombers could defend one another against enemy fighters and strike key industrial targets without fighter escorts.

“It was not very successful at first,” says historian Donald L. Miller, author of 2006’s Masters of the Air: America’s Bomber Boys Who Fought the Air War Against Nazi Germany. “We were not prepared for the realities of war, which led to extremely high casualty rates.”

Bomber crews flying at 25,000 feet faced danger in many forms. Exploding shells from antiaircraft batteries, known as flak, claimed many lives, as did oxygen deprivation and frostbite from the frigid temperatures at that altitude that could reach minus 40. Initially, aircrews were required to fly 25 missions before they could go home, but only one in five would ultimately achieve that total.

And, of course, the Luftwaffe fought back fiercely, picking off Allied aircraft. On February 26, 1943, one squadron of 53 Boeing B-17 Flying Fortresses witnessed the enemy’s wrath while flying back to England after successfully bombing industrial sites in Wilhelmshaven, Germany.

Among those aboard one of the B-17s was Stars and Stripes reporter Andy Rooney, who initially looked on in amazement as 100 German Focke-Wulf Fw 190 fighters screamed by at 450 miles an hour, each spitting death from two 13 mm machine guns and four 20 mm cannons. Then he and the airmen watched in horror as three B-17s fell, including one that exploded in midair, killing all 10 crewmen. Years later, Rooney recalled the silent flight home: “No one spoke...but everyone must have been thinking of it.”

At first, German pilots in Fw 190s and Messerschmitt Bf 109s were hesitant to attack U.S. bombers, which carried up to 12 .50-caliber machine guns each. However, they soon adopted a new tactic of flying at “12 o’clock high”—directly in front of the bombers—in order to shoot American pilots and disable their aircraft. It had a devastating effect.

“The Germans used cannons, rockets and machine guns to shoot down hundreds of bombers,” Miller says. “They also would fly through the formations and aim for the wings, where the fuel tanks were stored. American crews suffered horribly.” Without medics on the bombers, many bled to death.

As the losses of airmen and planes mounted, American military planners faced a critical decision about fighter support. An August 1943 raid on ball-bearing plants at Schweinfurt, Germany, during which U.S. Army Air Forces lost 60 aircraft and 600 crewmen, became the catalyst. “It was after that they said, ‘Look, we have to escort these guys all the way in,’” Harding says.

Early in the campaign, Republic P-47 Thunderbolts and Lockheed P-38 Lightnings had only been able to escort bombers part of the way to their target. After the late 1943 arrival of long-range P-51 Mustangs, fitted with reserve fuel tanks, American fighters could accompany bombers for the entire mission.

With bomber losses mounting, Allied planners increasingly focused on defeating the Luftwaffe by attacking both its aircraft and the industrial network that kept it flying. By early 1944, in preparation for the coming invasion of France, that strategy culminated in Big Week, when the USAAF and RAF flew nearly 6,000 sorties against the German aircraft industry while luring Luftwaffe fighters into the sky in an effort to win a war of attrition. More than 350 Allied heavy bombers were shot down, while the Luftwaffe lost a third of its aircraft and a fifth of its trained pilots.

After the Normandy landings, the campaign shifted to attacks on Nazi rocket sites and production facilities for petroleum, oil and lubricants.

“We targeted enemy aircraft through the entire war, but it became essential later on,” Miller says. “We went after ball-bearing plants because they were crucial for aircraft production, but we were also targeting power grids, marshalling yards and fuel production—everything we could hit to ground the Luftwaffe.”

In the end, the strategic air campaign had mixed success. The Combined Bomber Offensive crippled Nazi war production but never completely knocked out individual industries. The Germans relocated and rebuilt factories while continuing to churn out armaments, though never in the numbers needed to win the war.

The campaign’s major achievement was gaining air superiority. By the end of World War II, Allied bombers flew over Germany with little threat from enemy fighter aircraft. But the cost in human lives was enormous. The Allies suffered nearly 100,000 deaths while the Germans experienced an estimated 305,000 dead, 780,000 wounded and 7.5 million homeless. The U.S. alone lost some 8,000 heavy bombers with about 80,000 crew killed, wounded or captured.

“The strategic bombing campaign was essential to winning the war, but it did not win the war like the Americans thought it would,” Miller says.

Harding adds: “This was not a video game. Winning the war solely by air power was nonsense. You can’t win a war without boots on the ground.”