If you asked any Skylighter what they’d spent most of their time doing, to a man they’d say “stringing wire!”

Two men stringing wire during training, circa 1942. Numerous connections had to be made when a searchlight battery set up field operations, including telephone lines and hundreds of feet of cable linking generators, controllers, radar sets, searchlights, and ack-ack guns.

Once all that wire was strung, a searchlight battalion was ready to get to work.

During the operations prior to and after D-Day, the missions performed by AAA searchlight units were many and varied. The two main assignments consisted of (1) discovery and engagement of hostile aircraft, and (2) assisting the Allied air forces by means of homings, alerts, and many other services. Owing to the lack of enemy air activity (the Allied air forces had essentially cleared the skies of the Luftwaffe), searchlights were little used in their primary role of illuminating hostile aircraft during the latter half of 1944 and throughout the Winter and Spring of 1945. However, much was done to aid friendly aircraft in finding their bases in darkness, and to aid them in landing when otherwise forced to fly blind in adverse weather conditions.

Lt. Col. Aris B. Johnson, Commanding Officer, 422nd Night fighter Squadron, with whom the 225th worked closely throughout 1944, said “It is believed that the squadron operations would have been cut down at least 25% without the searchlights.” In later official statements, Johnson revised his estimate upward, stating that his combat efficiency would be decreased 50% without the lights.

The basic methods used by the Skylighters in combat are described in brief below. More details on antiaircraft searchlight tactics can be found here.

How four searchlights were used to form a canopy.

Canopy

Of all the types of assistance which searchlights were able to offer the Air Forces, the most called for and most important was the canopy. The standard deployment for lights in this form of assistance is such that four lights are situated in an approximate square around an airstrip. All light sections are given previously prepared azimuth and angle charts that permit them to form an intersection over the center of the airstrip. If the plane is coming in under the clouds, the lights are then clearly visible; if it’s flying above the clouds, the intersection on the cloud base will create a glow above the base that can be seen at a distance of approximately 15 miles. An example of this type assistance occurred near Airstrip A-58 on the night of 24 September 1944, when Section 4 of the First Platoon, Battery A, of the Skylighters picked up an aircraft showing no signs of being friend or foe. Upon illumination, the plane proved to be an American C-47 that immediately flashed an SOS. A canopy was formed and the plane landed safely. The pilot called the members of the searchlight section and thanked them personally because, as he stated, “I was completely lost and had only 30 minutes of fuel supply left.”

Homing on an adjacent airstrip by a searchlight battery located elsewhere. The effect was to create a virtual runway atop the real one using a light beam directed as close to the ground as possible.

Homing on Adjacent Airstrips

A less frequently used method of homing but one that was found to be invaluable in emergencies was homing on adjacent airstrips. When lights were deployed on objectives other than airstrips, light sections were furnished azimuths of all fields on which planes in distress in that area might be expected to land. Once a canopy was formed over a designated airstrip, one beam was exposed as nearly horizontal as possible in the direction of the desired airstrip for a period of 30 seconds. To catch the pilot’s eye, the beam was then elevated to 45 degrees and depressed three times quickly without being extinguished.

Two searchlights pointing straight up into the sky were used to pierce the clouds and provide beacons marking both ends of an airstrip for aircraft flying either above or below the ceiling.

Beacons

In forward areas, when there had been any indication that hostile aircraft were operating in the vicinity, it was found inadvisable to pinpoint the airstrip by forming a canopy. In such cases, when homing assistance was needed, either one or both of the searchlights that under normal conditions were placed at the ends of the runways, were exposed vertically as beacons. Under extremely unfavorable weather conditions, waving beacons were employed so as to seek out thin spots in the clouds where the beams could break through and attract the attention of the pilot. This method was found to be satisfactory under most conditions and ended up being used as the homing aid more than any other method except the canopy.

Beams of different colors were used to provide homing in low-visibility daylight conditions.

Daylight Homing

The aforementioned methods held true for daylight time and differed only in the colors of the beams. Different beam colors were accomplished by inserting colored filters over the face of the searchlight. A “wobbling” amber beacon was used to attracts a flier’s attention while green beacons designated the ends of runways. Any combination of colors were used and relayed to the air corps units operating in the vicinity, but from experience it was amber, yellow, and green that proved most successful when haze, fog, and/or low clouds obscured runways to pilots returning from operational missions. The use of red, amber, and green beacons on snow-covered landscapes proved highly effective in assisting pilots in pilots both looking for and landing on airstrips that would have otherwise blended in with adjacent fields and more treacherous spots to touch down in.

The technique of bouncing searchlight beams off the cloud base to light up a battlefield earned searchlight battalions the nickname “The Moonlight Cavalry.”

Battlefield Illumination

A less widely known use of AAA searchlights was for battlefield illumination, aka “artificial moonlight.” Throughout the major portion of the campaign on the Continent, the batteries of the Skylighters’ sister unit, the 226th AAA Searchlight Battalion assigned to the IXth Air Defense Command were, in turn, attached to Twelfth Army Group for this purpose. In that role, they worked with forward infantry elements and illuminated the area over which a night attack was to take place. The searchlights of the 2nd Platoon of Battery B of the 226th were employed from 7 to 16 February 1945 in direct support of front line troops. During this period, the 226th furnished illumination for night infantry attacks in the towns of Ferschweiler and Ernzen, enabled engineers to work at night building bridges across the Sauer River in the vicinity of Ballendorf, and provided airstrip illumination for field artillery observation planes operating at night.

Surprise and deception were obtained by the use of searchlights, and infantry troops once accustomed to them became ardent supporters of their use. Infantry commanders who at first demanded that the lights be put out, soon came to want them on all night long.

More on the use of artificial moonlight can be found here.

Two searchlights and a little math facilitated quick measurements of the cloud ceiling, an integral factor in no or no-go decisions for WW II air missions.

Other Uses

Searchlights were effectively employed to measure by triangulation the height of the cloud base above the Earth. They were also used frequently to illuminate airstrips to provide lighting for emergency rescues and night repair work on or near airdromes. They further strengthened airfield security during darkness by being put into action intermittently and sweeping over the field and surrounding areas.

Images in this section, unless otherwise noted, are reproduced from The IXth Air Defense Command Historical & Statistical Summary, January 1944 – June 1945.