| 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.