Junkers Ju 87 Stuka

Introduction

Thus the concentration of French land forces can be gravely troubled and subjected to very important delays. It will be the same for its transport.

Also, land operations will be rendered very difficult as the result of the power and frequency of enemy air intervention at the rear of the Armies and on the field of battle itself.

But as a prophecy of the things to come in 1940, Vuillemin's pessimistic assessment was remarkably accurate. It was probably not the opinion of the majority of French generals -- Vuillemin did not even bother to send a copy of his report to the Chief of the General Staff, general Gamelin. Nor was this wisdom going to help the French in any way, for the French air force completely failed to prevent this announced disaster. The weapon that would turn pessimistic prophecy into painful reality was the Junkers Ju 87, universally known as the Stuka. That was actually a generic term, shorthand for Sturzkampfflugzeug, to describe all dive bombers. The Stuka would become the symbol of the Luftwaffe, of its efficiency in ground support operations, of the terror that is spread, but also of its weakness as a strategic force. The success of the Ju 87 also contained the seeds of a disaster for the Luftwaffe, because it began to require that all its new bombers would be able to execute dive bombing attacks, including heavy mediums such as the Do 217 and heavy bombers such as the He 177. This policy was to be highly detrimental for the Luftwaffe.

The Origins of Dive Bombing

In normal (horizontal) bombing the released bomb has a horizontal, forward speed vector given to it by the movement of the aircraft. To this a vertical acceleration is added, caused by the pull of gravity, which causes to bomb to fall. The combination of the two results in a parabolic curve, which is distorted by the drag of the bomb and the wind. The basic idea of dive bombing is to make the speed vector of the aircraft coincide with the direction of gravity -- vertical -- so that the trajectory of the bomb becomes a straight line instead of a complicated curve. This greatly reduces the problems of bomb aiming. Because the bomb is usually released from lower altitude and at higher speeds, the effects of the wind are also minimised.

There are of course also disadvantages. A vertical or near-vertical dive results in a rapid build-up of speed, and airbrakes are needed to reduce the terminal dive velocity of the aircraft to acceptable limits. At the end of the dive, after the release of bombs, a sharp pull-out is necessary to keep the aircraft in the air, and this puts considerable stress on the aircraft. These requirements usually meant that dive-bombers had to be heavy, robust aircraft, with an unimpressive performance in level flight. Dive bombing also required highly specialised, intensively trained crews. These pilots not only had the technical problems of judging the diving angle correctly -- the natural tendency is to overestimate it -- aiming their bombs correctly, dropping them and then pulling out at the correct time. They also had to resist the mental and physical stress of a fast dive and a sharp pull-out manoeuvre.

The technique was first used during Word War I. The first officially acknowledged dive bombing attack seems to have been made by Lieutenant Harry Brown of the RFC (Royal Flying Corps) who sank a munitions barge in 1917. After the end of the war the RAF (Royal Air Force) conducted research and experiments, but finally decided that the method was too dangerous and halted its development. Instead, the British chose to concentrate their efforts on the creation of a strategic bombardment force. The FAA (Fleet Air Arm) kept the idea alive, but the development on its aircraft was seriously hampered by the RAF control over all aircraft, including shipboard aircraft.

The development of dive bombing continued in the USA. The USMC (US Marine Corps) practised dive bombing, although seldom at angles of more than 45 degrees, during operations in Haiti in 1919. A more refined form of the technique, influenced strongly by aviators who had flown in Europe during W.W.I, was used by them during the US intervention in Nicaragua in 1927. During these years, the USMC pilots also included spectacular dive bombing demonstrations in their air show routines. The USN (US Navy) adopted dive bombing as doctrine, not to provide ground units with tactical air support (as had been the goal of the USMC) but as an effective method to hit enemy ships - relatively small, moving targets. The aircraft used during these years were developments of the Curtiss Hawk family of fighter biplanes, the F6C and BF2C. The name of `Helldiver' was attached to these aircraft, although this would not become officially the name of an American aircraft until the Curtiss SB2C was introduced, during W.W.II.

In Germany, forbidden by the treaty of Versailles to develop military aircraft (a regulation which was often infringed upon, with the occasional help of the Russia, Japan, Sweden, the USA and other countries), the military leadership had to concentrate more on the theory of their application. Theorists developed the concept of a new style of mobile warfare, fought by Panzer divisions which combined tanks with motorized infantry and artillery, and intensively supported by attack aircraft. After Hitler came to power in 1933, work began to convert the theoretical concept into a real force. Ernst Udet, the head of the aircraft development programme of the Reichsluftwaffe, was very impressed with the demonstrations he saw in the USA in 1933. (Not because the concept of dive bombing was new to Udet, for the development of German dive bombers was already underway.) After he had flown the Curtiss Hawk, he bought two, which he demonstrated in Germany. This helped to advance the case of the dive bomber in Germany.

Birth of the Ju 87

In 1934 the Luftwaffe tested a modified Junkers K 47, an all-metal, low-wing monoplane with twin tail fins. The K 47 was originally designed as a two-seat fighter, and the diving tests were purely experimental. There was also an exchange of ideas with the Swedish airforce, which was also interested in dive bombing - and would, after the end of W.W.II, produce one of the most advanced dive bombers ever flown, the Saab 18. Then in 1936 the Luftwaffe selected a new dive bomber to replace the Hs 123. The contenders were the Arado Ar 81, the Blohm & Voss Ha 137, the Heinkel He 118 and the Junkers Ju 87.

Arado Ar 81

Blohm & Voss Ha 137

Heinkel He 118

Junkers Ju 87

The undercarriage was fixed and covered with ugly 'trousers'. The blunt-edged nose had a deep radiator, with entrance louvers, for its Rolls-Royce Kestrel engine. This was replaced in later prototypes and the Ju 87A series by the Jumo 210 engine, and a smaller, rectangular radiator bath. The fuselage itself had fairly gracious lines. It tapered upwards from the nose to the cockpit, so that the pilot had a good forward view. The view all around was excellent, thanks to a roomy greenhouse canopy for the two crew members. The slender tail structure is alleged to have been quite vulnerable to enemy fire, because the control lines were grouped close together.

Initially the rectangular, strut-braced tailplane had two small, rectangular endplate fins, but after the crash of the Ju 87V1, that was attributed to weakness of the tail, this was replaced by a large single tail fin.

The dive brakes consisted of a pair of long, rectangular strips attached to stubs under the wing leading edges. They were rotated perpendicular to the airstream to reduce the speed of the aircraft. Initially the brakes were not fitted to the first prototype, and after they were fitted the tail of the Ju 87V1 broke up during a dive test. But the third prototype (Ju 87V3) demonstrated its ability to dive at 90 degrees, and to resist a force of 6G during the pull-out. It was primarily this ability that made it win the competition.

Here are specifications for the Ar 81 and Ha 137. I did not find data for the He 118. Maybe someone can fill in the gap?

Type:	Ar 81 V3	Ha 137 V4
Crew:	2	1
Engine:	640hp Junkers Jumo 210Ca	610hp Junkers Jumo 210Aa
Wing Span:	11.00m	11.15m
Length:	11.51m	9.47m
Height:	3.61m	2.79m
Wing Area:	35.60m2	23.50m2
Empty Weight:	1925kg	1810kg
Maximum weight:	3070kg	2411kg
Maximum Speed:	345km/h at 4000m, 300km/h at SL	300km/h
Ceiling:	7700m	7000m
Climb:	4000m in 11min	2000m in 4min
Fixed Armament:	one 7.9mm MG17	two 7.9mm MG17 and one 20mm MG FF
Rear Armament:	7.9mm MG15	none
Bomb Load:	250kg	one 250kg and four 50kg

Development History

Ju 87A

The Ju 87A-0 pre-production model entered service in the spring of 1937. The engine was the Jumo 210, which was to be retained in different versions by the production A-series: the Jumo 210Ca for the A-1, and the Jumo 210Da for the A-2. Production of the A-series ended after 262 aircraft, at the end of 1938.

The Junkers Ju 87A had two fixed, forward-firing MG 17 guns, installed in the wing outboard of the undercarriage attachment points. There was a flexible MG 15 in the rear cockpit. The Ju 87A could carry a 250kg bomb, or a 500kg bomb if the rear gunner was left home. The bomb was carried on a swing-down rack, a tubular structure of which the front end was attached under the engine. On release, the bomb was swung forward and downward, so that it was free of the propeller disc. (The swinging bomb crutch seems to have been an American invention. The USN considered it important enough that they refused, in 1939, to allow export of such bomb racks to France! The logic behind that decision is difficult to explain.) There were also two small racks for SC50 bombs under each outboard wing panel.

The Ju 87A did not see combat, with the exception of three aircraft which were sent to Spain during the civil war, but it was important in the development of the automatic bombing system of the Ju 87. This consisted of an Askania autopilot, which was used together with a Revi gunsight. The bomb release gear, elevator controls, and dive brakes were linked to this system. Before attacking the pilot would set the bomb release height. The deployment of the dive brakes automatically adjusted the elevator trim tab, and put the aircraft into a dive. When the bomb release height was reached and the bombs were dropped the autopilot adjusted the elevator trim tab again, so that the aircraft became tail heavy and pulled itself out of the dive. The use of the elevator was forbidden, except in case of emergency.

The pilot thus needed not to be concerned too much with the pull-out. This was just as well, because the pull-out put a an acceleration of 6G on aircraft and pilot. Under such conditions one could not expect the pilot to perform complicated control sequences. Normal procedures called for a bombr release at an altitude of about 900m, which brought the Stuka down to about 400m before it started to regain altitude.

Ju 87B

The trousered undercarriage of the A-model was replaced by a `spatted' one, with closer-fitting leg covers and better streamlined wheel spats. The change was more than cosmetic, for the undercarriage was also redesigned and considerably strengthened. The mainwheels were also moved slighlty backwards. If the Ju 87 had to operate from poor airfields, such as found at the Eastern front, the spats were often removed because they tended to get clogged with mud. It was not even uncommon for Ju 87s to have their undercarriage ripped off when operating from such airfields. On the undercarriage legs a fitting was installed for a siren, a so called `Jericho Trumpet', to enhance the effect on morale of the Ju 87's attacks. This was driven by a small propeller on the left undercarriage leg. When the siren was not installed the mount was faired over, leaving a protrusion on the undercarriage. The sirens were mostly discarded during the Battle of Britain, because they reduced the performance of the already slow and vulnerable Ju 87.

The greenhouse canopy of the Ju 87B was also different of that of the Ju 87A, with sliding sections for the pilot and the gunner, which replaced the earlier hinged entry panels. The twin radio masts of the JU 87A were replaced by a single, tall, vertical mast.

Ju 87C

The wings of the Ju 87C had a smaller span and folded outboard of the undercarriage attachment points. The folding was similar to that used by the Grumman F4F Wildcat: the wings folded backwards with the leading edges turning down, so that they could be stored flat against the sides of the fuselage. The Ju 87C of course also had attachment points for catapult launch and a tailhook for arrested landings. The landing gear was made jettisonnable for a ditching, and flotation bags were fitted.

The Ju 87C also had the capability to carry underwing fuel tanks, extending its range from 800km to 1600km. This was to be retained for another (land-based) production model, the Ju 87R.

Because the Graf Zeppelin was never completed, the Ju 87C only operated from land bases.

Ju 87R

An additional fuel transfer system was fitted, new fuel tanks installed in the wing, and the outer wing attachment points were modified so that 300l fuel tanks could be carried instead of bombs. The R-1 and R-2 were equivalent to the B-1 and B-2, but the R-1 had a longer range, because the B-2 model was heavier than the B-1.

Ju 87D

There were also other aerodynamic refinements. The greenhouse canopy now tapered aft, instead of having a nearly constant cross-section as had that of the B-model. The aft gunners exchanged the single drum-fed MG15 gun for twin belt-fed MG81 guns.

The bomb release gear was better faired in, and the maximal bomb load was increased to 1800kg. This could include a 1400kg armour-piercing bomb on the centreline rack. The landing gear was again strengthened, but nevertheless the Ju 87D retained a reputation for landing gear collapses on rough runways. The wheel covers were again changed, and the fitting for sirens were eliminated.

The D-3 introduced additional armour, because the Ju 87 now more often had to dodge the fire of the troops it attacked. From the D-4 model onwards the 7.9mm win guns were replaced by the 20mm MG151/20 cannon. The D-5 model had a longer wing span, with pointed wing tip extensions. An interesting development was the D-7, which had night flight equipment and radar.

Ju 87E

Ju 87G

Initially, the Ju 87G was seen as quite dangerous to its crews. The additional weight and drag of the wing guns adversely affected performance and handling, and low-level attacks in the face of the Russian AAA and fighters seemed suicidal. But true as that was, it remained that the Ju 87G was extremely effective. The 37mm gun was in 1943 considered obsolete as an anti-tank gun on the ground, but from the air it was still effective, because the Ju 87G could attack tanks from the rear or from above, were their armour was much thinner. Not that the Germans refrained from trying out bigger cannon on anti-tank aircraft, but the Ju 87 could not possibly carry these, and larger aircraft such as the Ju 88 were not agile enough to operate successfully against tanks.

There were two versions, the G-1 and the G-2, with short and long wing spans, respectively -- the G-2 was based on the long-wing D-5 model. Production of the Ju 87 was halted definitively in October 1944.

Ju 87H

Ju 87K

Specifications:

Combat History

Evaluation in Spain

The war in Spain was more important for the Ju 87 than the other way around, for it was in Spain that the Germans developed their air-ground cooperation doctrine.

Poland

That first day of the war was not an overall success for the Luftwaffe and the Ju 87. Most of the strength of the Luftwaffe was sent far behind the lines to destroy the Polish air force on the ground, but without conclusive results -- it was estimated that the Poles lost about 30 aircraft by it. But during the next days the co-operation between the armed force and the Stukas proved to be excellent. Every time the Polish army tried to organise resistance to the rapid advance of the tanks, Stukas were called in to destroy it. The largest Polish counter-attack, when 170,000 men attacked the rear of the 10th Army in the battle of the Bzura, was brought to a halt under the relentless air attacks, before the Polish were surrounded at Kutno.

If the quick German success in Poland was watched with admiration as well as concern in some other countries, the fate of Warsaw was a warning of the barbarism that the war would bring. Technically, the attacks of German bombers on the fiercely defended Polish capital may have been allowed by the rules of warfare. Nevertheless, the destruction of the city caused great anger. It also had a strong effect on the minds of other allied leaders, who would during 1940 being reluctant to defend cities against the advancing German army, if this meant that they would be mercilessly destroyed from the air.

The Germans indeed made a propaganda movie about the Ju 87, and the devastation it had caused in Poland. Allegedly, the Germans bombarded parts of Warsaw after the end of the fighting, to get more impressive footage for this production... It ended with a threat against England, if it did not seek peace. As far as England and the Ju 87 were concerned, it was a hollow threat.

Denmark and Norway

The attacks of the Stukas concentrated mainly on the allied attacks to recapture Narvik and Trondheim by landings at Harstad, Namson and Andalsnes. They did inflict considerable losses on the attackers, although they did probably not change the outcome of this operation, which was doomed from the start by the stupidity of allied planners and the events in France. At Narvik the Luftwaffe sank a cruiser, and damaged two others and the old battleship Resolution. For the Royal Navy this was a serious lesson about operating under enemy air superiority -- a lesson that some people refused to listen to, and others would quickly forget. But the commander of the French troops in Norway, a man with the confusing name of Mittelhauser, admitted later:

At any rate, when the Stuka was revealed to us, when we saw the British fleet giving up before Trondheim (because of it), we had the feeling that we were face to face with something quite new, and of a technical surprise whose employment to be decisive.

France and the Low Countries

The fatal breakthrough on 13 May near Sedan was preceded by an attack of the Ju 87s on the positions of the French defenders. Small groups of Stukas methodically attacked the villages in front line, road crossings and artillery positions. Even the Germans, moving forward under protection of these attacks, were frightened -- perhaps understandably, because there had been a few "friendly fire" incidents during the campaign in Poland. The French general Ruby reported:

The infantry, cowering and immobile in their trenches, dazed by the crash of the bombs and the shriek of the dive bombers, were too stunned to use their anti-aircraft guns and fire. Their only concern was to keep their heads down and not move. Five hours of this punishment shattered their nerves. They became incapable of reacting to the approaching enemy infantry.

When the French commanders saw their mistake, they began to ask for British fighter aircraft to protect their troops. They were unaware that because of monumental incompetence, most of the French air force had remained inactive. Three quarters of the French fighters were never committed to the battle. The Luftwaffe was free to attack anything that moved. Most of that movement was to the rear. The Ju 87s, sometimes flying nine missions per day, cleared the road for the German forces which brushed irresistably through France. Some French units launched limited counter-attacks, such as General de Gaulle's 4th armoured division, but they were immediately attacked by the Ju 87s, and forced to retreat:

Until sunset they continued to bomb us, and the consequences were wrecking for our vehicles, which could not leave the road, and our artillery, which could find no cover.

The Luftwaffe's attack on Dunkirk, however, showed the limitations of both the Luftwaffe and the Ju 87. The French and British soldiers, finally accustomed to the screaming attacks of the dive bombers, resisted admirably, defending the city until almost all the British and many of the French soldiers could be evacuated over sea. At the same time, the operations of the RAF to protect the evacuation caused heavy losses for the attackers, although a large number of ships was sunk or damaged. It was the first sign of the vulnerability of the Ju 87.

The Battle of Britain

Then the Stukas turned their attention to the British airfields. Attacks on Detling, Lympne, Hawkinge and Tangmere followed. But by now the Fighter Command and taken measure of the Stuka, and the attacks of the next days would make it clear that the Ju 87 was a sitting duck for the Spitfires and Hurricanes of the RAF. On 18 August the so-called "Stuka-slaughter of Thorney Island", when a large formation was caught without fighter cover, cost the Luftwaffe 30 Stukas -- shot down, crash-landed, or damaged beyond repair. This forced the Luftwaffe to pull back the Stukas from the offensive against Britain. They continued operating against shipping in the channel, also at night, but no longer participated in the main effort. The Ju 87s were conserved for the actual invasion.

Ju 87 in Italy

Yet it was clear that dive bombers were a very effective weapon against British ships in the Mediterranean. As was proven by the Germans when sent Stukageschwader I and II to the help the Italians. The Stukas badly damaged the carrier Illustrious, sank the cruiser Southampton, damaged several other ships, and nearly cut off the supply line to the besieged Tobruk.

So by 1941 the Italians received 46 B-1s, 50 B-2s, 59 R-2s. In 1943 they received an additional 46 aircraft, D-2s and D-3s. The Italians gave the aircraft the nickname Picchiatelli, which means "Striker". Although the Italians were trained initially to use the same tactics as the Germans, who did dive vertically on their targets in small groups, they soon developed their own methods. Rather oddly, the Italians also used the Ju 87 for the method which later became known as skip bombing -- horizontal attacks at very low level, dropping their bombs in such way that they would bounce of the water and hit the attacked ship on the waterline. The advantage of this method of attacking was that the target was hit on the waterline, and a dive directly into the defensive fire was avoided.

The Eastern Front

The task that would come to the Ju 87 on the Eastern front was the destruction of enemy tanks. One of the things that the Germans had not accounted for in their war plans was the enormous number of tanks the Red Army had, and their qualities had escaped the observation of most. Confronted with the presence at the of large numbers of excellent T-34 tanks, and the disappointing production of their own industry, the Germans sought to compensate their numerical inferiority in other ways. For the Ju 87 it was a "target-rich environment". The giant tank battle of Kursk, the largest ever, saw the participation of large numbers of Ju 87s.

But the Ju 87s now had to operate from often very primitive airfields, at the end of long supply lines, and in a harsh climate. Aircraft had usually to be maintained in the open air, and hangars or shelters for parked aircraft were non-existent. Equipment broke down in the Russian winter. Rudel wrote:

The engines no longer start, everything is frozen; it is suicide to trust the instruments.

Tactics changed from dive-bombing to low-level attacks, and finally the use of dive bombing was abandoned entirely by the Ju 87G versions. Because of the dangerous nature of such operations, the armour of the Stuka was substantially increased. Of course it became even more dangerous when the Soviet air force gained the upper hand, because it first and foremost wanted to achieve tactical air superiority over the battlefield, where the Ju 87s flew. The obsolescence of the Ju 87 was now seriously felt, and the type was increasingly replaced by the fighter-bomber versions of the Fw 190.

If the Ju 87 continued to be effective, it was mostly because of the very experienced crews. The most successful Stuka pilot was Hans-Ulrich Rudel, who was to become the most decorated German pilot of W.W.II. He was also the pilot who flew the most combat missions -- a staggering 2530. He was credited with the destruction of the battleship Marat, 519 tanks, and over 2000 other vehicles. According to one rumour, Hitler was so impressed by Rudel's actions that he contemplated naming him as his successor!

Evaluation

To him the Ju 87D-3 - then completely obsolete - imparted an "almost oppressive" sense of vulnerability. The pilot sat high a the greenhouse company, with an excellent view all around, but also terribly exposed. The Ju 87D-3 accelerated well on take-off, but climbed slowly, and was both too slow to escape from fighter attack and too stable to evade it. Briefly, the Ju 87 was an "ideal target", even for the most inexperienced fighter pilot.

On the other hand Brown confirmed that the Ju 87 was ideal for dive bombing, "a genuine 90 deg screamer", in which it felt quite natural to be in a vertical dive. Dive bombing practice in the Ju 87 he found "more enjoyable... than I had ever experienced with any other aircraft of this specialist type."

Before the dive, the aircraft had to be trimmed for cruise conditions, the bomb release altitude was be set, and the cooler flaps closed. Deploying the dive brakes automatically put the Ju 87 into a dive, and engaged a security device which limited the control column movement to 5 degrees from neutral -- enough to give effective control for bomb-aiming, but preventing manoeuvres which could overstress the aircraft. After bomb release the Ju 87 pulled itself out of the dive. The pilot then closed the dive brakes, and climbed away.

Compared with other dive bombers, the Ju 87 left a favourable impression. If it was vulnerable, it was not more so than the Douglas SBD Dauntless, the Aichi D3A Val, or the Blackburn Skua. And it was more accurate than any of those.

Comparison

The Blackburn Skua was a British dive bomber and two-seat fighter. It was rather too slow and cumbersome to be an effective fighter, and was rapidly replaced by the Fulmar. As a consequence, the FAA did no longer have a dive bomber after the Spring of 1941. The Skua eyed a bit more modern than the Ju 87, because it had retractable landing gear, but it was quite ugly. Its diving characteristics were good. The usual dive angle was 70 degrees, and its dive brakes were modified 'Zap' type trailing-edge flaps.

The Douglas SBD Dauntless was the standard dive bomber of the USN for a good part of the war, and continued in service until the end. It played a very important role in several battles in the Pacific -- the most famous that of Midway, where SBDs sunk four Japanese carriers. The SBD too had retractable landing gear, and it had better streamlining than most contemporary dive bombers. Thus it had a relatively good performance. It also had good diving characteristics, and diving angles between 70 and 75 degrees could be achieved. The dive brakes were large trailing edge flaps which were perforated to reduce the buffet. Nevertheless, it was admitted to be an obsolescent and vulnerable aircraft. It just happened to be still better than its intended replacement, the Curtiss SB2C Helldiver.

The Aichi D3A Val was the most important Japanese dive bomber of the war, which was produced until January 1944. The more modern Yokosuka D4Y appeared only when the war was already lost for Japan. The D3A shared the fixed landing gear of the Ju 87 and had similar dive brakes: rotating strips attached under the wing leading edges. But its other features, such as the elliptical wing, showed mostly Heinkel influence. During the first year of the war, with very highly trained and experienced crews, the D3As achieved a hitting rate of about 80%. They were agile enough to be used as dogfighters after they dropped their bombs, but when the USN pilots improved their tactics the D3A became very vulnerable.

Type:	Junkers Ju 87B-1	Blackburn Skua	Douglas SBD-5 Dauntless	Aichi D3A2
Engine:	1200hp Junkers Jumo 211A	830hp Bristol Perseus XII	1200hp Wright R-1820-60 Cyclone	1075hp Mitsubishi Kinsei 44
Crew:	2	2	2	2
Wing Span:	13.20m	14.07m	12.66m	14.53m
Length:	11.00m	10.84m	9.91m	10.25m
Height:	3.77m	4.32m	3.94m	3.35m
Wing Area:	31.90m2	28.98m2	30.19m2
Empty Weight:	2760kg	2493kg	3028kg	2618kg
Maximum weight:	4400kg	3733kg	4322kg
Maximum Speed:	350km/h	362km/h at 2040m	407km/h at 5060m	450km/h
Dive Speed:	600km/h	407km/h	445km/h
Ceiling:	8100m	5820m	8075m	10880m
Climb:	3000m in 8.8min	5820m in 43min	3050m in 8min
Range:	800km		2084km	1560km
Fixed Armament:	2*mg7.9mm MG17	4*mg7.7mm	2*mg12.7mm	2*mg7.7mm
Rear Armament:	1*mg7.9mmMG15	1*mg7.7mm	2*mg7.62mm	1*mg7.7mm
Bomb Load:	1000kg	227kg	815kg	370kg

Sources:

• Wings of the Luftwaffe. Captain Eric Brown, published by Pilot Press (1977, 1979) and by Airlife (1987, 1993).
• Wings of the Navy. Captain Eric Brown, published by Pilot Press and by Jane's, 1980.
• Dive Bombers in Action. Peter C. Smith, published by Blanford Press, 1988.
• Stuka! Joachim Dressel, published by Arms and Armour Press, 1989.
• The Collapse of The Third Republic. William L. Shirer, published by Heineman Ltd., and by Secker and Warburg Ltd., 1969.
• The Encyclopedia of German Military Aircraft. Bryan Philpott, published by Arms and Armour Press, 1980.
• Hermann Goering - Ijzeren Ikaros. Andre ver Elst, published by De Vlijt.
• Chronicle of Aviation. Edited by Mark S. Pyle, Bill Gunston, and Eduouard Chemel. Published by Chronicle Communications, 1992.
• Who's Who in Aviation History. William H. Longyard, published by Airlife, 1994.
• The Aerospace Chronology. Michael J. H. Taylor, published by Tri-Service Press, 1989.
• Messerschmitt `O-Nine' Gallery. Thomas H. Hitchcock, published by Monogram, 1973.
• Jane's Fighting Aircraft of World War II. Published by Bracken Books, 1989.