These notes are based on actual use of the Stuka.
Weapons Carried.
Against hard and fixed targets high-explosive bombs at 50 - 500 kg size were customarily used. For attacks against men and vehicles fragmentation bombs of 1 - 500 kg were used - the smaller 1 kg and 2 kg size being dropped in containers. To increase the fragmentation effect special fuses known as Dinort sticks were screwed into the nose caps of the larger bombs. The sticks were literally just that, causing the bomb to detonate some 30 centimetres above the ground.
Basic Forms of Attack.
Depending on the target there were 3 basic forms of attack: a near-vertical nosedive (Sturzangriff) onto the target, from a height of 5 - 15,000 ft at an angle of 60 - 90 degrees; and an oblique or shallow dive (Schragangriff) from a height of 2100 - 3000 ft at an angle of 20 - 50 degrees, and a low level attack (Tiefangriff) - when the approach was made at low altitude, never more than 900 feet. On a shallow dive approach bombs were usually released in a 3 - 600 m long carpet and the Stukas machine guns used also to strafe the target area. For a low level bombing attack delayed-action fuses were fitted to the bombs. In all 3 forms of attack the bombs were dropped singly or in pairs when possible. Major Friedrich Lang, one of the most experienced dive-bomber pilots of WWII, has written that the dive bomber was best suited to attacking small important targets such as bridges, ships, trains, buildings and armoured fighting vehicles. Bombing accuracy depended on the angle of descent of the bomb and this was determined by the aircraft diving angle. In Lang's opinion the most efficient diving angle was roughly 70 degrees from the horizontal. Lines painted at various angles on the cabin side panels which the pilot aligned with the horizon the facilitated aiming (Aces High - apply this to next patch? - Ed).
The role of the Stuka vis-a-vis that of the conventional bomber was never clearly defined, but the tendency was to employ them primarily in direct support of ground operations rather than on missions into areas remote from the fighting. Unlike conventional bombers, Stukas ready operated singly. Attacks were normally carried out by complete Wings, as experience showed that an assault, in successive floods of three, by a total of 30 or more Stukas usually guaranteed destruction of the target. 30 planes was the average operational strength (as against the established strength of 52) in a Wing of 3 squadrons. For mutual self support the Stukas always flew in a tightly packed V formation - Vs by flights (that is, Ketten of three planes) grouped into squadron Vs, which in turn formed a wing V. This permitted the maximum benefit to be derived from the overlapping fields of fire at the Stukas machine guns.
Before WWII the tactics of Stuka attack stipulated an approach at an altitude of about 18,000 feet. The enemy could not be sure of the Stukas objective at this height so an element of surprise was retained until the actual attack was launched; at the same time the danger from anti-aircraft fire was minimal. As Stukas neared their target they could drop down to the altitude at which they were to commence the bombing dives, where possible they attacked against the wind and from out of the sun. On completion of the mission the return flight to base was made in open formation, making maximum use of the cover afforded by cloud and the terrain.
Lessons Learned.
These tactics changed in 1939 when Stuka operations in Poland showed that an 18,000 ft approached the target was unnecessary. Moreover the need to use oxygen masks at this attitude made it positively undesirable. From these early operations individual Stuka pilots also concluded that their attacks were better when they did not use the cumbersome dive breaks with which they JU87B-1 s were fitted. Admittedly in a 70 degree dive the brakes brought the speed down from 400 mph to 280 mph (Aces High - computer modelling? Ed.) and so made aiming easier. Apart from being a tedious business, slamming the brakes in and out upset the flight formation and made the pilots nervous at a time when they were supposed to be concentrating on aligning the aircraft with the target and releasing the bombs. Another factor militating against use of the dive brakes was an upsurge in Polish anti-aircraft activity, when all too often the approach to and flight from the target area demanded more, not less, speed. In the event it was concluded that aiming, accuracy and the height at which the bombs were released were not adversely affected when the air brakes were not used. Also the longer levelling out radius at the end of the dive path resulting from the high speed could be decreased by the pilot levelling out more sharply. however this resulted in blood draining from the retina of the pilot's eyes producing a temporary loss of vision for about a second. A device called a Hohenlader was fitted to the JU 87B. This cut in automatically during a dive, to relieve the pilot of the problem of when to level out. In practice it was of dubious value because it interfered with the aiming process. For this reason the Hohenlader was not fitted to later versions of the Stuka, and the point at which the pilot pulled out of a dive was left to his discretion.
Defence Against Enemy aircraft.
During the Polish campaign the Stukas were able to carry out their mission without any real concern for enemy fighter aircraft, as the Polish Air Force rarely appeared. It was a different story when Germany invaded Russia however, and the need for German fighter cover soon became apparent. On their own the slow-flying Stukas could only hope to partially compensate for their vulnerability by manoeuvrability and by flying in formation. The immediate answer was for them to operate under the protection of German fighter aircraft. But this proved to be a short-term solution. During the second half the campaign in North Africa, subsequently in Italy and later in North-West Europe, allied air superiority coupled with a deterioration in the quality of aircrew training virtually ruled out employment of Stukas except in suicide missions. Therefore in the spring of 1944 most of the Stukagruppen had started to convert to the FW190 and by the autumn of that year only one JU 87 Group was still undertaking daylight sorties (this was Rudels IIIl/StG2 Wing on the Russian front).
Once in the air when the target had been recognised and cited, the squadron would shake-out into an appropriate formation for the attack. Depending on the nature of the target this could vary from a single ‘line ahead’ to a formation in which the squadrons flew in Vs abreast of each other. The V formation had the advantage that dropping the bombs was quicker and the wing was better able to defend itself if enemy fighters pounced as Stukas were leaving the target area. The only difficulty was that a closely packed formation restricted the manoeuvrability of individual planes and thus when they were taking evasive action there was always a risk of collision. When attack was conducted in a single ‘line-ahead’ formation, getting back into these for the return flight often proved difficult. This was due to increasing confusion in the target area as successive planes screamed down to drop their bombs. The rule was for the leading planes to head back towards base at a speed which would enable the last aircraft the line to catch up. Unfortunately the speed was rarely slow enough and the only alternative was to circle round the target area. Stukas were especially vulnerable in such circumstances and enemy fighters are known to have joined such circles and shot down JU 87s in quick succession as they overtook them from the rear. The signal to form up for the return to base was normally given by the Wing Commander (Flying in one of the leading Stukas) either by waggling his wings or over the radio. An overcast sky covered by heavy cloud was a boon to Stuka operations as it had not only bought an element of surprise but also hampered enemy anti-aircraft activity. Enemy fighter aircraft also found the task more difficult, but so did the German fighters protecting the Stuka mission.
Bombing in Practice.
The normal load was a 250 kg bomb carried in a cradle behind the radiator, and for 50 kg bombs in racks under the wings. A bomb release button on the control column enabled pilot to drop all bombs together or separately. The crutch carrying the 250 kg bomb was mounted on swing links which lowered and swung the bomb forward on release so that it cleared the airscrew. Depending on the target the bombs were fitted with impact or delayed-action fuses; release height in a dive attacked varied between 1800 ft and 3000 ft and during level attacks not less than 600 ft (this was the minimum safe altitude, determined by the time between release and bomb detonation). Successive dive bombers had to release their bonds at virtually the same height for if pilot dropped his bomb too soon the explosion would endanger the aircraft in front. Stukas operating in close support of ground troops usually dropped the 50 kg wing bombs first as they almost invariably were of the high fragmentation variety. The three basic forms of attack had been briefly described. The average Sturzangriff (nose - dive) attack was launched from an altitude above 12,000 ft – a Schragangriff (oblique) dive usually began at about at an average altitude of 2400 ft. However every operation was determined by factors which varied according to the situation, such surprise, atmospheric conditions and, above all, the enemies anti-aircraft defences; but experience proved that an effective dive bombing attack could not be launched from an altitude of less than 6000 ft.
Extracts from “Stuka JU-87” by Lt-Col AJ Barker – due acknowledgement made.
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