1. GENERAL

Originally developed by the United States Army and Navy in the late '20's, the technique of dive-bombing was soon adopted by the German Air Force, which tested it under actual war conditions during the Spanish Civil War. In the present conflict the Germans have found dive-bombing tremendously profitable, especially in Poland and on the Western Front. As a special method of precision bombing, it is known to have been successful against artillery positions, front-line troops, bridges, crossroads, rail centers, dumps, and anchored ships. The main purpose of the dive-bomber is to drop explosives on vital parts of a target, with maximum surprise and minimum risk.

The development of dive-bombing was presumably an attempt to overcome the inaccuracy of the earlier bombsights and to give additional velocity to the bomb itself, thereby increasing its penetrative and armor-piercing qualities.

2. TYPES OF PLANES

At present the Germans seem to prefer the Junkers 87 as a dive-bomber for low-flying attacks. For higher dive-bomber attacks, they are likely to use the Junkers 88 and the Dornier 217.

Everyone has heard a great deal about the German Stukas. The name "Stuka" may be applied to any one of several models of the Junkers 87. The 87's are low-wing, two-seater monoplanes, equipped with diving brakes to limit their speed. The wings are crank-shaped. The armament consists of two fixed machine guns in the wings, and one machine gun flexibly mounted in the rear cockpit. The plane has wing racks for four 110-pound bombs or two 220-pound bombs, and a carrier, underneath the fuselage and between the landing gear struts, which will carry a 550-, a 1100-, or a 2,200-pound bomb. When the 1100- or 2,200-pound bombs are carried, the wing bombs are omitted.

3. TACTICS

An average of 30 to 40 German dive-bombers take part in an attack. These planes ordinarily fly at an altitude of 14,000 to 17,000 feet, with escort fighters about 1,000 to 2,000 feet above them.

When the objective is sighted, the entire unit either attacks a single target or divides into smaller formations, which seek out individual targets previously assigned to them or attack the single target from different directions.

The dives are generally made upwind, since this permits greater bombing accuracy. The flight commander usually dives first. At the order to prepare to dive, the pilot sets his diving brakes, closes the oil cooler and cylinder radiator a little more than halfway (to keep from cooling his engine too much), switches on the reflecting sight, and adjusts the bomb-release. He then lets the plane slide off on the left wing, and, sighting his target through the bombsight, goes to town.

The rate of dive, varying with different types of dive-bombers, is regulated by the throttle and is maintained throughout the pull-out up to the moment of climb. Single- and twin-engine bombers use automatic bomb-releasing mechanisms which compute the height of release and angle of dive; otherwise this must be estimated by the pilot.

After the pull-out, the planes swoop down to about 100 feet from the ground in order to escape antiaircraft fire, and, while low, they machine-gun any target in sight. When the planes have reassembled, they seek cover in clouds or climb up through them to a high altitude and head homeward in close formation.

4. EFFECTIVENESS

The success of German dive-bombing operations has invariably been made possible by the absence of any real fighter opposition. In France, dive-bombing was used successfully as a barrage to precede the advance of mechanized troops—it was not employed during the first phase of the advance into Belgium. During this Belgian phase, heavy attacks on United Nations airdromes were made by high-altitude bombers and fighter planes. Only after United Nations air strength had been considerably reduced did the dive-bombers put in an appearance.

In Crete, dive-bombers attacked airdromes prior to landings by parachute troops. Fighter planes strafed antiaircraft and other ground defenses. Here, as in Poland, the Germans had no air opposition.

Dive-bombing is expensive. When opposed by first- class fighter planes, the enemy has frequently suffered losses as high as 50 percent. Antiaircraft barrages often have caused dive-bombers to release their bombs at an altitude of 3,000 to 4,000 feet with a consequent loss of accuracy. Dive-bomber pilots in many cases have been seen swerving sideways near the end of their dive in an effort to avoid the barrage, dropping their bombs hundreds of yards wide of the target.

Unopposed, and in conjunction with ground troops, the dive-bomber has proved effective, but it is by no means the most potent weapon of the war, nor can it claim to have replaced artillery fire.