By mid-March 1944, it was clear to Allied planners that there simply would not be enough amphibious landing vessels available by May—and even then, these would have to be borrowed from the Mediterranean theater. More time would be required for training as well; both Troop Carrier and airborne personnel needed more practice.

The Troop Carrier training program prior to NEPTUNE was unequaled at any other time during the war. Gen. Paul Williams, who took over IX Troop Carrier Command near the end of February, brought along many experienced staff members from the MTO, which included North Africa, Sicily, and Salerno operations. Much attention was given to night formation flying, practice jumps, and glider tows with live airborne troops. Troopers were assigned, when possible, to practice with the Troop Carrier units with whom they would fly into Normandy.

A school was established at North Witham to formally train Pathfinders; it was commanded by Lt. Col. Joel L. Crouch, a former pilot for United Airlines and a strong advocate of Pathfinder operations who had led the successful Pathfinder mission at Salerno. Prior to NEPTUNE, a small number of flight crews from each of the IX TCC groups based in England, along with small teams of paratroopers from the 101st and 82d Divisions, trained together here in Pathfinder techniques. Crews were taught state-of-the-art navigation, and troops were taught how set up the “Eureka” beacon, which worked in tandem with the “Rebecca” sender-receiver in the cockpit as a radar-type aid. [Note: The Eureka beacon weighed approximately 55 lbs. An “interrogator” unit in the cockpit (Rebecca) showed the location of the Eureka on a cathode ray tube. The blip that showed on the Rebecca indicated bearing and, less accurately, distance. Eureka beacons were set to send their responses on specific frequencies so that Rebeccas used by specific serials could identify the proper Eureka beacon in cases where several drop or landing zones were located in proximity. IX TCC estimated that Rebecca could generally be relied on to pick up Eureka from about 16 miles out, though Rebecca could detect Eureka at greater distances from higher altitudes. Accuracy was estimated at approximately two miles, due largely to the fact that the blips representing the Eureka and the airplane tended to merge at that distance.] Troops were also taught to mark the T’s on a Drop Zone with other aids, including holophane lights (strong, directional electric lights), colored panels, and colored smoke (see “The Pathfinders: Origins and Evolution,” by Joel Crouch in Into The Valley, Chapter 5).

To cap off the training period prior to the invasion, all Troop Carrier groups and most Airborne units flew a large-scale and realistic practice exercise, code named EAGLE, on the night of 11 May. The skies were clear, and results were generally very good. More practice missions were conducted through 29 May, and all units were judged ready.

Eisenhower, who had evolved in the past several months into a proponent of large-scale airborne missions in Normandy, now played a major role in crafting a plan for the airborne assault that was vital to the success of NEPTUNE. Controversy, however, seemed part of the domain of airborne operations, and several times it grew quite hot during the planning stages at SHAEF. Air Commander-in-Chief for OVERLORD, Air Marshal Trafford Leigh-Mallory made the stunning prediction to Eisenhower that possibly 50-70 percent of the Troop Carrier aircraft would be shot down in the American airborne assault. Aircraft used as jumping platforms would by definition be flying so slowly at such low altitude as to make them easy targets, as would the towships and gliders. They were unarmed, had little or no armor plates, and were without self-sealing fuel tanks. Furthermore, because of stiff opposition on the ground, now known to be building, the airborne forces who succeeded in landing, according to Leigh-Mallory, would be quickly overwhelmed by German ground forces (Warren-97, 11). Consequently, Leigh-Mallory asked Eisenhower to cancel the American airborne phase of the invasion. Eisenhower took Leigh-Mallory’s request under advisement, but continued to push the planning process forward.

German Build-up & Last-Minute Moves

Just before the invasion, the Germans had 60 divisions in western Europe, approximately 25 percent of their strength. Of these, 36 infantry divisions and six panzer divisions were located on the coast facing England (Britannica, 770). Many of these were undermanned. Fortress Europa was also defended on the west by the Atlantic Wall, a jumble of steel obstacles, heavy guns, mines, concrete bunkers, tank traps, and barbed wire. Field Marshall Erwin Rommel inspected the construction upon his arrival in France in December 1943, and reported to Hitler that its defenses were inadequate.

Field Marshal Gerd von Rundstedt, Commander-in-Chief of Western Forces, believed that the Atlantic Wall would be a temporary delay at best, providing him time to get his tanks and tactical reserves into position for a counterattack. The old guard, of which Rundstedt was a part, believed in the traditional strategic principle of encirclement: the landings would provide him the time and maneuverability to surround the enemy. Rommel believed that the invading force would be at its most vulnerable during the landings, and should be attacked immediately. “‘Don’t let them land,’ was Rommel’s strategy. ‘Let them come,’ was Rundstedt’s. . . motto” (Carell, 9).

Hitler, always distrustful of old-guard Prussian generals, put Rommel in charge of defending the area of coastline including Pas de Calais and Normandy. However, Rommel was still under the command of von Rundstedt, though with direct access to the German dictator. Hitler added to the confusion by placing two of the Panzer divisions under his own direct control. In one of his fleeting moments of insight, Hitler had decided that Normandy was indeed a likely invasion site. French underground reports indicated a regular influx of men and equipment by late spring, including a Panzer division and experienced infantry troops. Reinforcements in the Normandy area were beginning to increase at a rate which was causing concern.

Throughout the spring, Rommel had gone all-out to beef up the Atlantic Wall. He supervised the laying of nearly four million mines and increased gun emplacements. Back in the dunes behind the beaches he had overseen the laying of pipes which ran from kerosene tanks that could be easily ignited on command. He ordered areas between the beaches flooded, leaving only five causeways for travel inland. Thousands of poles and trees were buried to obstruct landings by airborne troops. These were known as “Rommel’s asparagus.” Some of these were connected by wires and buried with mines, so that when jarred, the landing zone turned into a minefield. Few, however, had been armed.

The German high command, which had anticipated a May invasion, looked nervously toward early June, when the combination of moon and tides would again be right. However, German weather forecasters offered assurances of stormy weather, and the German military relaxed (Dank, b, 29-33).

Elaborate plans for deception were implemented by the Allies, including a phantom army, the First Army Group. This army, though composed of both real and fictitious elements, was commanded by Gen. George Patton and gave all indications that it would spearhead the invasion in the most logical place, at the Pas de Calais, the narrowest point in the English Channel. Artificial tanks made of plywood and landing craft made of rubber were assembled, clearly visible from the air. Massive amounts of radio transmissions confirmed the heavy workload of the First Army Group as it prepared for battle. Ultra, meanwhile, had cracked the Enigma code used by the Abwehr (Hitler’s espionage/counter-espionage organization), and had identified or captured every German spy in England (and continued to do so throughout the war). Many of these spies were used to feed deceptive information back to the Germans, and helped add credibility to the ruse created by the First Army Group. Decoded Enigma transmissions verified that the Germans were gearing up mightily to do battle with this non-existent force (Bradley & Blair, 219-20).

Another Allied plan to foster confusion involved RAF bombers that were to fly to appropriate locations and drop large amounts of foil, called “Window,” that magnified and distorted radar images. Dummy paratroops, pintail bombs and rifle simulators, along with some actual demolition troops, were organized for diversion drops. Thirty war ships, towing numerous large, foil balloons that created an image of a massive fleet on German radar, were prepared to sail for the Pas de Calais. From their decks, loudspeakers would broadcast simulated battle sounds. Radar and fighter control stations along the north coast of Normandy would be bombed prior to D-Day, and jammed during the missions. Nine thousand tons of bombs would be dropped on coastal defenses immediately before the invasion began.

Coincidentally, the book Paratroops, by Czech Capt. F.O. Miksche, who was serving in England with the Fighting French Forces, came very close to predicting key aspects of the Normandy airborne plan. Around the beginning of May, the book began to arouse concerns among Allied commanders, when they realized that the Germans undoubtedly had this book as well. Miksche had accurately identified much of the drop zone area in a theoretical airborne assault—by three divisions—into Normandy. In accompanying amphibious landings, also hypothetical, Miksche identified the area around Utah Beach for the sea-borne assault.

Though Allied intelligence confirmed the German buildup in Normandy earlier in the spring, there was another striking development that had emerged by 25 May. According to messages translated from the cracked German code, the German 91st Air Landing Division, which had attached to it the 6th Parachute Regiment (under Lt. Col. Freiherr von der Heydte) had moved to Saint Sauveur le Vicomte and into the drop zones of the 82d Airborne. It was learned from coded messages that the specific purpose of these two units, as well as several others, “was to repel possible Allied airborne operations” (Blair, 207).

It was known at this time that the east coast of the Cotentin peninsula was bristling with both light and heavy anti-aircraft guns, but Intelligence had yet to get a clear estimate of Luftwaffe capabilities. It was also known that Goering had a considerable force of usable aircraft which he had ready for the invasion. Numerical estimates ranged from 850 to 1,099. During the period when more than 5,000 Allied warships began to converge on the coast of England in preparation for the assault, however, not many German aircraft appeared, and those that did were almost immediately shot down. Up until D-Day, the question of Luftwaffe strength remained unanswered. 

Several squadrons of Allied nightfighters were assigned to fly cover for the paratroop missions over the Channel, and to eliminate flak and searchlights. Bombers would attack these positions in the interim between the Pathfinders and the main formation in order to flush them out, and nightfighters would then move in for the kill. Other nightfighters equipped with radar would patrol at 5,000-6,000 ft. in the area between the Troop Carrier formations and German airfields, while several squadrons of nightfighters were assigned to circle Luftwaffe bases. The daylight missions, on the other hand, would be escorted by three fighter groups from IX Fighter Command.

All of these problems and uncertainties combined to create a contentious and troublesome situation within the Allied command. Leigh-Mallory again confronted Eisenhower and tried to convince him to cancel the American airborne missions, and thus avoid a “futile slaughter.” Bradley proposed moving the DZs of the 82d away from Saint Sauveur le Vicomte, and consolidating the 82d DZs near the 101st DZs near Sainte Mère Eglise.

Troop Carrier routes on D-Day were designed to approach the Cotentin peninsula from the west, which would not only avoid some of the German guns, but Allied naval guns as well. A ten-mile corridor was established by the navy, and two-foot-wide “invasion stripes”—three white interspersed by two black—were painted on the fuselages and wings of all Troop Carrier aircraft, including gliders, for purposes of recognition. This time the night of the invasion would be lit by a half moon, weather notwithstanding.

If the 82d DZs were moved, however, new routes leading from the DZs back to England would direct many C-47s out over Utah Beach. The navy, however, “because of the importance attached to the airborne missions,” reluctantly agreed that in such circumstances naval guns would withhold all fire at all aircraft during the times the Troop Carrier missions flew (Warren-97, 12).