Seventy years ago, a formation of United States Army Air Forces Lockheed P-38 Lightning fighters was photographed as it roared over an unidentified foreign field. It's hard to spot the familiar US insignia of the white star on a blue circle, but the black and white stripes the Lightnings wear stand out easily - which is a very good thing. In 1944, in the months leading up to the invasion of Nazi occupied France, the Allied planners of Operation OVERLORD realized that on the day of the invasion - D-Day - the skies over the invasion zone would be filled with aircraft: waves of Allied fighters and photo reconnaissance planes, bombers, troop-carrying gliders and their tow planes. They were expected to be met by fierce Luftwaffe opposition. The planners feared friendly fire - anti-aircraft fire from Allied naval vessels and Allied troops - against their own air flotilla, and pilots mistakenly engaging in dogfights against their own comrades in arms. The existing system for identifying friendly aircraft, Identification Friend or Foe (IFF), would in all probability be overwhelmed by the sheer number of aircraft over the beaches. To avoid fratricidal incidents, the D-Day planners called for paint and brushes, and ordered that the aircraft of the Allied Expeditionary Air Force and supporting units be painted with alternating black and white stripes on wings and fuselage - 18 inches wide on single-engine aircraft, and 24 inches wide for twin-engined craft. They were called invasion stripes. Tests showed that the stripes were easily visible on the ground and in the air - easier to see than the usual national markings that Allied aircraft bore, so a simple order - if it ain't got stripes, shoot it down - could be given out to Allied gunners and pilots. For fear of the Luftwaffe getting wind of the scheme and confusing the issue by painting their own stripes, the plan was a closely guarded secret.
On the first of June, a small flight bearing the invasion stripes overflew the Allied fleet to familiarize the crews with the markings. The orders to paint the stripes were finally issued - on June 3 for troop carrier units, and on June 4 to the fighter and bomber squadrons. The harried ground crewmen scrambled for paint and brushes while they prepared their aircraft for their missions.
In the early hours of June 6, thousands of aircraft, all bearing invasion stripes, headed for the skies over Normandy. As D-Day unfolded, friendly fire incidents were thankfully few. And, strangely, the Luftwaffe just didn't show up - only three German aircraft overflew the beaches that day. Two of the pilots, ace Josef “Pips” Priller and his wingman Heinz Wodarczyk, were said to be hungover from some serious partying the night before. The black and white stripes had served their purpose, and by December 1944, air units had been ordered to remove them. But the photographs of the airplanes survive to remind us of one of the most striking symbols of that day 70 years ago. And, in commemoration of D-Day, the Royal Air Force has painted a Eurofighter Typhoon with invasion stripes, so once again the alternating black and white stripes will be seen over European skies.