German dive bombers Junkers Ju-87 A-1. Dimensions: length 10.8m, wing span 13.7m, wing area 31.9sq.m. Weight: empty 2,310kg, max. take-off: 3,390kg. Engine: Jumo 210D, 640hp. Max. speed: 318km/h. Range: 990km. Ceiling: 7,000m. Rate of climb: 9.25m/sec. Armament: 2mg. Bombload: 500kg. Crew: 2.

Italian dive bomber Caproni Bergamaschi AP-1. Dimensions: length 9.8m, wing span 13m, wing area 24sq.m. Weight: empty 1,940kg, max. take-off: 2,500kg. Engine: Alfa Romeo 126 RC.34, 780hp. Max. speed: 347km/h. Range: 1,500km. Ceiling: 6,500m. Rate of climb: 8m/sec. Armament: 3mg. Bombload: 500kg. Crew: 1-2.

French dive bomber Loire-Nieuport LN-140. Dimensions: length 9.63m, wing span 14m, wing area 26.3sq.m. Max. take-off weight: 2,470kg. Engine: Hispano-Suiza 12, 690hp. Max. speed: 340km/h. Range: 900km. Ceiling: 9,000m. Rate of climb: 5m/sec. Armament: 1 gun, 3 mg. Bombload: 400kg. Crew: 2.

Japanese dive bomber Aichi D3A1 (Val). Dimensions: length 10.2m, wing span 14.36m, wing area 34.9sq.m. Weight: empty 2,408kg, max. take-off: 3,650kg. Engine: Mitsubishi Kinsei 44, 1,070hp. Max. speed: 389km/h. Range: 1,472km. Ceiling: 9,300m. Rate of climb: 7.8m/sec. Armament: 3mg. Bombload: 310kg. Crew: 2.

Soviet dive bomber OPB-5. Dimensions: length 8.28m, wing span 10.40m, wing area 18sq.m. Weight: empty 2,806kg, max. take-off: 3,842kg. Engine: PD M-90, 1,425hp. Max. speed: 600km/h. Range: 660km. Ceiling: 9,900m. Rate of climb: ?m/sec. Armament: 4mg. Bombload: 500kg. Crew: 1.

The attractive at the first glance theory of Gen. Giulio Douhet, prophesizing a total air war, did not fool the leading military brains of different countries. They understood that deploying heavy horizontal bomber planes against the enemy troops dispersed in the battleground would be ineffective: capable only of area-bombing, and on top of it - from high altitudes, they hardly would be able to destroy highly mobile armoured troops and motorized infantry.

The destination of heavy bombers were strategic raids against enemy deep rears and industrial centres. But where was the guarantee that before they be destroyed, land forces would not reach the very airfields, which furnished those raids? Sooner or later it became obvious that without successes of the traditional infantry no other branch of service would be able to wrestle the final victory.

Therefore the objective was defined clearly: direct support of own troops in the battlefield, elimination of enemy armoured and motorized units (down to individual tanks and AFV's), observation and commanding posts, bridges, artillery emplacements, and other small but important targets. But there emerged the problem of how to accomplish that. Obviously, it required better bombing precision and reduction of dispersal to the minimum.

And how to guarantee the precision of bombing and avoid targeting errors? Aircraft constructors came up with the only plausible solution: precision of bombing may be guaranteed, if the direction of bombing coincides with the axis of the bomber's motion and points at the target under an angle close to 90°. Those requirements could be met in only one way: a bomber needed to attack the target, while diving vertically, at maximum speed, literally at a breakneck pace.

The first plane meeting those requirements was the American Martin M-125, which went into production under the marking Martin BM-1. It was the first aircraft using a special device to drop a bomb, hung under the fuselage, while diving (before, bombs were installed under the wings). That device had a form of metal tubes that swung the bomb downward and forward before release, so that it would stay clear of the propeller.

To combat enemy ships in the Mediterranean Sea, the Italians had developed the dive bomber Caproni Bergamaschi AP-1. It was designed in 1935, but in 1939, when the process of improving had finally ended, the plane was already so obsolete that it saw service only in training squadrons.

An interesting construction was the 1935 French plane Loire-Nieuport LN-140 with the landing gear retracting into nacelles under inverted gull-wing. The nacelles served not only as the bays for the retracted landing gear, but also as the mounting point of the dive brakes. That idea, however, was found ineffective and the construction of the nacelles was changed in favour of extending the landing gear to act as an aerodynamic brake (versions LN-410 and LN-411). Those aircraft saw combat actions in the short-lasting campaign of 1940.

In the beginning of 1930s also the command of the Imperial Japanese Navy expressed the need in diving bombers. Yet, since the Japanese aircraft industry at that time had no experience with manufacturing this class of planes, it was decided to order the prototype abroad. The choice was made in favour of the German Heinkel He-50 (with changes according to the Japanese specifications designated He-66). First planes were delivered to Japan in 1933, and two years later company Aichi Kokuki produced its first planes designated D1A1, which were immediately commissioned for service. Next modification of that aircraft, D1A2, was in service till the end of 1941, that is until Japan entered the war.

Experience gained during the production of those aircraft allowed Aichi to design its own plane, which became one of the standard Japanese aircraft of the Second World War. That was the Aichi D3A1, with the American moniker Val. Those were Vals that constituted the core of the assault group, which attacked Pearl Harbor on 7 December 1941.

In the Soviet Union it was not until 1938 that a prototype of such a plane was developed by Sergei Kochergin, a constructor of interesting experimental aircraft. His dive bomber OPB-5, commissioned in 1941, was designed for powerful M-90 engine, whose production was not yet fully implemented when the war broke out. Therefore, the construction was changed to fit the serial M-85A engine, which however proved too weak, and the plane's technical and combat characteristics fell behind those of the modern ground-attack ones. In 1942 it was decided to terminate production of the OPB-5.

It is interesting that the aircraft designed primarily as combat planes fighting naval targets had made their biggest career in supporting operations on the land. And the best known one among them was definitely the notorious Junkers Ju-87 Stuka (abbreviation for Sturzkampfflugzeug - diving combat aircraft) that gained its infamy during the initial period of the Second World War.

The situation of the German aircraft industry after the First World War was catastrophic: the Treaty of Versailles forbade Germany to keep, and above all - to manufacture, military aviation. There began hectic efforts to find the ways to bypass the provisions of the treaty. And the bypasses were found. There were created numerous foreign subsidiaries of the German companies, which started studies and production of the combat aircraft of German origin. The founding companies in Germany were producing only the civilian versions of those aircraft. Particularly animated was co-operation in these matters with the Soviet Union and Sweden. The co-operation with the Soviet Union resulted in establishment in 1925 of the German aviation school in Lipetsk, which became the proving ground for new aircraft and their tactics, as well as training of the German airmen until 1933.

But the most important was the subsidiary of the Junkers Aircraft Works (Junkers Flugzeugwerke) established in Malmo, in neutral Sweden, together with the company AB Flugindustrie. There engineers Karl Plauth and Hermann Pohlmann, pioneers in all-metal aircraft construction, in 1928 designed an interesting plane: Junkers K-47 fighter capable of diving and carrying bombs. That plane, with minor alterations, was used in Germany as a mailplane under designation A-48.

Coming of Adolf Hitler to power in Germany in 1933 brought open violations of the provisions of the Treaty of Versailles, and fostered development of the German aircraft industry at a growing rate. What is more, it was then, when studies on the best aircraft models of various types were made. Junkers Flugzeug- und Motorenwerke AG (JFM) were nationalized, and Hugo Junkers, who was not an enthusiast of the Nazi régime, had to retire. He died in 1935. The works on the new model of an aircraft, designated No.87, were continued under the management of Hermann Pohlmann.

At the end of 1935 the prototype was ready. It was a genuine plane for its time: all-metal construction, with two-seat closed cockpit, fixed landing gear with distinctive fairings, inverted gull wing, semi-floating flaps and twin-tail. It was powered by Rolls-Royce Kestrel V 12-cylinder liquid-cooled engine of 640hp.

That Ju-87 V1 made the first flight on 17 September 1935. Test flights revealed insufficient horizontal stability of the new plane, as well as inefficiency of the flaps. And then, on 25 January 1936, during a test dive, it crashed killing two experienced pilots - twin fins and rudders proved too weak.

The next prototype had already a single vertical stabilizer and a new engine Junkers Jumo 210A of 610hp. Yet now the sight from the pilot's cockpit was obscured by the engine. Next prototype had the engine lowered for better sight; it was also the first one to have the aerodynamic brake installed. It lowered the velocity of the dive, and increased the precision of the bombing. That became the decisive factor of the success: In 1936 the new head of the technical development office of the Ministry of Aviation, Ernst Udet, opened a tender for a dive bomber for the re-created German Air Force (Luftwaffe), in which took part companies Arado, Blohm & Voss, Heinkel and Junkers. Junkers won the bid.

After tests were made with the fourth prototype at the air-base Rechlin, the first series of Ju-87A-0 with enlarged empennage was produced. And the first planes Ju-87A-1 reached air force units in the beginning of 1937. This modification was already fully equipped for combat operations. In the end of 1937 the Ju-87A-2 modification with the 680hp engine was commissioned for the German Air Force.

In December 1937 the first unit of Ju-87s (one A-2 and two A-1s) were included into the Legion Condor, and saw combat in the Spanish civil war. They made their first strikes against the republican positions on 7 February 1938. In October they were reinforced with five new Ju-87s of B-1 modification with the 1,000hp engine Jumo 211A, additional machine-guns in the wings, and altered hood and fairings. Spain became the proving ground that had demonstrated the qualities of the Ju-87: precision of bombing surpassed all expectations. The plane was secret though. After the end of hostilities all the aircraft of the Legion Condor were left to the fascist government, with the exception of the Stukas, which were taken back to Germany (one plane was lost in combat). So ended the first episode of using the dive bombers in the building of the "new world order".

And there came next episodes: invasion of Poland in September 1939, which saw Ju-87B-1 in combat (28 lost); invasion of Denmark and Norway in April 1940, which saw the new modification Ju-87R with bigger range; and invasion of France and Low Countries in May 1940 where Ju-87s were used for the first time as the psychological weapon - their fairings were fitted with "Jericho Trumpet" wailing sirens. There also for the first time the aircraft revealed its disadvantages in encounters with modern French and British fighters. They showed in full during the Battle of Britain: low speed, inadequate agility, lack of armour, and weak defensive armament, which brought a completely new psychological effect - more and more often German crews evaded the combat, dropped bombs chaotically, and flew away back to their bases with the first British fighters in sight.

The Battle of Britain was the beginning of the end of the Ju-87's career. Efficient in the conditions of absence of adequate anti-air defence, Ju-87s proved helpless in face on strong anti-aircraft artillery and all Allied fighter planes. New modifications were not able to change the situation. That had been demonstrated very clearly on the East front. If in 1941-1942 the Stukas were terrorizing the troops and the civilians practically with impunity, later, despite of adopting for the Luftwaffe newer modifications D and G, they could not withstand Red Army's air force and anti-air defence.