Throughout the dark hours of the morning of the June 6 1944, the skies over the English Channel hummed with activity. As the dawn broke, Bomber Command airmen returning from a sortie in Normandy looked down at the Channel below and reported seeing “more ships than sea”. It wasn’t until landing that they realised they had been involved in the seminal D-Day.The Normandy landings, codenamed Operation Neptune and known as D-Day, was the largest seaborne invasion in history. While records often focus on the beaches, it is all too easy to forget what was happening in the air.
Planning and preparation
Planning for Operation Neptune began in 1943 and the RAF was vital to the preparations.
A series of carefully planned and secretly executed airborne operations in the lead up to D-Day prepared the ground for the seaborne invasion on 6 June.
In the months leading up to D-Day, Allied airforces, including the RAF and American bomber forces, attacked their targets over Germany, hitting aircraft production facilities, fuel supplies and airfields. These attacks forced the Luftwaffe on to the defensive, and depleted resources and supplies.
For two months before 6 June, RAF Bomber Command had been tasked with destroying road and rail links in a ring around the Normandy battle area to cut off routes for German forces and prevent their easy access to supplies and reinforcements.
The RAF was also instrumental in leading deception operations to draw the attention of the German forces away from Normandy and the proposed landing sites.
Operation Titanic was carried out on 5 and 6 June by the RAF and Special Air Service (SAS). Overnight four squadrons dropped 400 dummy paratroopers in four locations in north-western France to draw the German forces away from the Normandy coast and make them believe a large-scale parachute landing was in progress. Each dummy contained a noisemaker to simulate the sounds of rifle fire and a small timed explosive to destroy the dummy. SAS teams were also dropped and, upon landing, played recordings of shouting and firing. The aim was to encourage rumours of large numbers of paratroopers landing in the area. The mission was a success and during the Normandy landings some German regiments were employed in searching the woods along the coast for parachutists, keeping them away from the beaches.
Overnight on 5 June RAF Bomber Command was employed in more diversionary tactics, under codenames Operation Glimmer and Operation Taxable. The idea was to fly a small number of aircraft back and forth over the sea at a constant speed of 8 knots to make it look as though a huge fleet of ships was heading for the French coast at two locations, 60 and 100 miles east of the D-Day landing sites.
Operation Taxable was carried out by the renowned “Dambusters” 617 Squadron and Glimmer by 218 Squadron. The Lancasters of 617 Squadron and the Short Sterlings of 218 Squadron took off in pitch black on the night of 5 June in appalling weather. Flying in line abreast, or in a wall formation, with two miles between each aircraft, the crews were tasked with creating a seamless flying sequence which would remain consistent on radar imagery.
Once over the sea, the crews dropped chaff, or strips of aluminium foil out of the aircraft. The chaff swamped radar screens, giving the impression of the movement of a large fleet of ships.
As the two squadrons flew meticulous circuits in complete darkness, just along the coast thousands of ships prepared to land on the Normandy beaches.
D-Day - 6 June 1944
As the first ships landed on the shores of northern France at 6:30am on 6 June, the noise on the beaches would have been overwhelming; the thumping of heavy munitions, a constant rap of machine gun fire, the churning of motors in the cold sea, the voices of the thousands of men, and the skies overhead full of the roar of aircraft.
Even after all the preparation, planning and deception operations, the RAF still had an enormous part to play on D-Day. As the ships ploughed into the beaches and thousands of feet landed on French sand, Lancasters and Halifaxes took to the skies once again to bomb the gun batteries that defended the sea. Fifty squadrons of RAF Coastal Command swept the shores looking for enemy ships and submarines, and RAF Fighter Command squadrons worked to protect the fleet, while air-sea rescue crews patrolled the coastlines pulling injured men out of the water.
If troops on the beaches had looked upwards, they would have seen the sky transformed into a sea of stripes. With so many aircraft flying on D-Day the risk of friendly fire was very high, so three white and two black ‘invasion stripes’ were painted boldly onto the fuselage and underneath the wings of Allied aircraft to distinguish them clearly.
As well as fighting in the air, RAF crews and mechanics worked on the ground. RAF personnel and vehicles landed on the shore and immediately began work. Mammoth tasks ensued, including the establishment of radio and radar facilities to help direct RAF Fighter Command who were defending the beaches from the air. Not one Allied ship was sunk during the invasion and only two enemy aircraft successfully attacked the beaches.
The RAF's contribution
The RAF’s contribution to D-Day was monumental. In preparation and planning, and during the distraction operations, RAF Bomber Command lost 300 aircraft and 2,000 men.
In total 5,656 RAF aircraft were involved in D Day and 1,800 RAF personnel with 456 RAF vehicles landed ashore. 
By 9 June over 3,500 RAF personnel and 815 vehicles were working in Normandy on airfield construction and aircraft servicing. 
None of the RAF servicemen involved in the preparatory operations were aware of the historic significance of their contribution until after the landings. Even during the final flights on the night of 5 June the squadrons had no idea what was about to happen, or how instrumental their input would be in gaining the Allies a foothold on the beaches of northern France.