RAMSTEIN AIR BASE, Germany (AFNS) -- The mention of "D-Day" conjures iconic images of men storming a beach riddled with barbed wire, smoke and craters created by German mortar batteries; of men advancing toward machine gun nests and acts of heroism as they made their way inland to secure a foothold in mainland Europe.

However, without the efforts made by the allied air campaign in the months prior, D-Day would have never been possible.

"The Allies disrupted aircraft production," said Billy Harris, a U.S. Air Forces in Europe and Air Forces Africa historian, "but more importantly, they inflicted severe losses on the Luftwaffe in air-to-air combat as it tried to defend the factories. Allies also hit airfields within 350 miles of the beachhead with 6,700 tons of bombs, and the Germans withdrew many of their fighters to protect Germany."

The figure of 127 downed Allied aircraft during the battle of Normandy may pale in comparison to the estimated 10,000 Allied casualties from the ground, but the casualties surely would have been much higher had they not conducted such a successful air campaign in the months prior.

The planning for D-Day, dubbed "Overlord", began more than two years prior when the Combined Chiefs of Staff approved the general invasion plan that would ultimately be carried out by Gen. Dwight D. Eisenhower, who took over as the commander of the European theater just a few months prior to the invasion.

From the beginning of planning it was recognized that the air component to the invasion was going to be critical. From experience, the Allies knew facing an air adversary over the battlefront was not going to be successful, so they planned on crippling the Luftwaffe in strategic stages leading up to the invasion.

The Allies had the perfect combination of warfighting planes to deal a devastating blow to the German air arsenal.

"Both the P-47 and P-51 were veritable workhorses during the war," Harris said. "The sleek, highly maneuverable P-51 proved ideal for long range escort missions and an equal match to the Luftwaffe's fighters. Pilots who flew it praised its maneuverability and visibility during close order engagements with enemy fighters.

“The heavier P-47, also capable of short and medium-range escort and formidable foe during dogfights, proved ideal during interdiction missions,” he said. “Capable of carrying half the bomb load of a B-17, the P-47 Thunderbolts of (the) Ninth Air Force inflicted significant damage on enemy ground forces throughout the Normandy campaign."

The air campaign had three stages: disable the Luftwaffe; cut off main supply roads; and once the invasion began, focus on battle field interdiction and close air support.

From January to June 1944, the five months leading up to D-Day, the Allies had effectively clipped the wings of the German Luftwaffe. The allied air forces engaged the Luftwaffe wherever they found them while bombers sought out their "nests" in France and Germany.

By the end of May, bombers had neutralized dozens of airfields and severely crippled Germany's aircraft industry. As a result, on the eve of Normandy the Luftwaffe had been reduced to less than half of its original air assets. In May alone, 570 German aircraft were destroyed, which equated to roughly 25 percent of their total force in the span of 30 days.

Another goal of the Overlord plan involved the destruction of the enemy's rail communications. Of particular interest were the rail lines leading towards the Overlord beach areas. To meet this objective, allied air forces unleashed heavy and medium bombers to engage marshalling yards. Meanwhile, fighters attacked rolling stock and troop concentrations. Pilots claimed 475 locomotives and hundreds of railcars loaded with munitions, supplies, and troops. In turn, the attacks demoralized German forces which delayed reinforcements to the Overlord areas.

The Allies were not without their own losses, though. In that period leading up to the invasion, the Allies lost more than 12,000 men and 2,000 aircraft.

"Without a doubt, the air campaign was a key part of reducing the Luftwaffe's capabilities," Harris said. "Between Feb. 1 and June 1, the Luftwaffe lost 8,445 fighters. That equated to pilot losses of 20-25-percent each month, resulting in a staggering turnover of crews. It also meant diminished experience and crippling losses that could not be replaced. The tremendous valor and sacrifice of Allied aircrews ensured marginal Luftwaffe presence over Normandy in June."

By the time of the invasion, the Luftwaffe was barely able to generate 100 sorties to respond to the Allied invasion on the coast of France.

The importance of airpower was evident even before World War II, but the success of the air campaign leading up to Normandy solidified air supremacy as a key component in our multi-faceted military.

"The Luftwaffe was a formidable foe," Harris said. "It had proven its abilities over England, France, and Russia. One can only imagine the havoc 8,000 fighters would have unleashed on the troop ships approaching the beaches, not to mention the carnage on the beaches themselves."