1. GENERAL
German antiaircraft units are an organic part of the Luftwaffe (air force), and
aircraft, especially fighter planes, cooperate with the antiaircraft defenses. The
Germans make a distinction between searchlight units, light and heavy antiaircraft
artillery units, and barrage balloon units.
2. USE OF SEARCHLIGHTS
In addition to seeking out our planes so that antiaircraft fire can be placed on
them, German searchlights recently have been producing "dazzle" and "glare" in
efforts to blind and confuse our pilots, bombardiers, and gunners. These tactics
are proving a big help to the Germans in protecting cities and strategic centers.
Dazzle is the blinding of persons in a plane caught in the direct light rays of one
or more searchlights. Glare means obscuring the target from the plane crew by a light
beam played between the plane and the target.
The extent of dazzle is determined by the height of the plane, the number of
searchlights concentrated on it, weather conditions, the direction of the light
beams, and, to some degree, by the reactions of persons in the plane.
Dazzle is most effective when a plane is flying at a height
between 2,000 and 4,000 feet. A single beam will not produce dazzle
except at a fairly short range. At a given height, the dazzle increases
in direct proportion to the number of beams centered on the plane. It also
increases in proportion to the amount of haze, mist, rain, or dust in the
air. Far more dazzle is produced if the plane is traveling in the general
direction of the beam or beams. The British find that when a bomber pilot
gets into one of these areas, he must keep his head down and fly by
instruments, so as not to allow the light to blind and confuse him.
Dazzle or glare created by antiaircraft searchlights greatly lowers the
ability of a person to adapt his eyes to seeing at night—in fact,
looking at any fairly strong light will do this. Either dazzle or glare
makes the location of targets difficult and lessens the accuracy of
bombing. Also, keeping beams directly on a plane helps defending fighter
craft to approach the plane unobserved and to attack it more effectively.
German searchlight crews are reported to have been dipping their light beams
to indicate to their fighter planes the direction in which hostile bombers
are flying.
Sound-locator apparatus are used by the searchlight units to determine the
general direction and distance of our aircraft from the searchlight positions. Having
obtained these data, the searchlight crews seek to place their lights on the
planes. When searchlights are not present in an area, or are present but unable
to function, sound-locator apparatus often are employed in close cooperation with
antiaircraft artillery in estimating firing data.
3. USE OF ANTIAIRCRAFT ARTILLERY
Antiaircraft guns are the backbone of the entire anti-aircraft defense. The
battery, usually consisting of four or six guns, is the fire unit. Experience
has shown the Germans that it is best not to break up this unit, even when a
need arises elsewhere for only one of the guns. It should be noted, incidentally,
that the Germans often employ flashless propelling charges to avoid giving away
the location of antiaircraft weapons.
a. Heavy Batteries
The heavy battery is responsible for the antiaircraft defense of the combat
zone. The heavy antiaircraft guns (usually 88-mm) have the mission of protecting
German ground forces at all times against air reconnaissance and high-altitude attacks.
These weapons are moved by mechanized transport. Their average marching speed
is from 5 to 20 miles per hour. Horse-drawn antiaircraft cannon are employed
only by commands which must cope with fuel shortages and unsatisfactory
roads. Antiaircraft units provided with mechanical transport have the following
characteristics: ability to open fire quickly, great mobility, and capabilities
for employment within the effective range of hostile artillery.
The heavy batteries are employed against hostile planes, especially attack
units, flying at altitudes up to about 27,000 feet. Heavy antiaircraft artillery
cannot be used against planes flying at altitudes of less than 1,200 feet
directly over the battery. Requiring special fire-control equipment and
special ammunition, these weapons are used against ground targets only in
the event of close-in tank attacks. Each heavy battery is protected by
two 20-mm cannon, which are an organic part of the battery itself.
b. Light Cannon
Light antiaircraft cannon are especially suited for defense against planes
flying at short ranges and at low altitudes. The mission of the light
antiaircraft battery is to protect installations and troops against
ground-strafing and dive-bombing attacks. The cannon (usually 20-mm) are
moved either on trucks or on self-propelled mounts. These weapons are
characterized by their great mobility and by their success in tracking
air targets which have a high angular rate of travel and which demand
change of ranges. Tracers are used to make this tracking easier. The
average marching speed of units equipped with these weapons is from
15 to 25 miles per hour.
c. Machine Guns
In heavily populated areas, especially the strategic manufacturing
centers, machine guns often are mounted on the roofs of buildings to
operate against aircraft flying at relatively low altitudes. It is known
that in many instances machine guns are manned by well-trained factory personnel.
4. USE OF BARRAGE BALLOONS
The Germans make considerable use of captive balloon barrages around
strategic manufacturing centers and other areas containing important
installations. The barrage usually forms an irregular belt about 5/8 of
a mile wide and about 1 3/4 miles from the outer edge of
the strategic area. The plan for a barrage is coordinated with
light- and medium-caliber antiaircraft gun defense, which protects the
larger gaps in the belt.
The balloons, resembling the fan-tailed goldfish sometimes seen in a
home aquarium, have fan-like tails as long as the balloons themselves. They
are reported to be moored at altitudes ranging as high as 15,000 feet, and
at an average altitude of 4,500 feet. A well-planned barrage, with its
dangling net of steel cables, can prevent precision bombing, and can
keep hostile aircraft at an altitude favorable for the use of antiaircraft
artillery and fighter planes. Also, a barrage reduces the efficiency of
hostile combat aviation by forcing it to operate at unfavorable
altitudes.
On the other hand, the Germans have learned from experience that balloon
barrages are not well suited to protect small, isolated targets. They have
also found that such a barrage is vulnerable to hostile fighter planes, and
serves its purpose only in areas where it can be protected by antiaircraft
guns and friendly fighters.