Dive bombing tactics using the example of Stuka.
Following the tactics employed with the Junkers Ju 87 Stuka are described in detail; the dive-bombing methods used by the twin-engined Junkers Ju 88 were essentially similar, though the actual dive was somewhat shallower (60° during the early part of the war, reduced to 50° later).
The steep-dive attack was one of the most accurate ways of bombing. On the completion of their course at the specialist Dive Bomber school, crews were expected to be able to get 50% of their bombs within 25m (27yd) of the centre of the target; the comparable distance for high-flying horizontal bombers was two to three times larger. Furthermore, against operational targets, which were usually defended by anti-aircraft guns, the errors for all types of bombing were two or even three times as great as those indicated on the training ranges. Thus, although the divebombing attack was not accurate enough to be worth-while against small, hard targets such as individual tanks, it was very effective against soft targets, such as motor vehicles, which were vulnerable to near misses.
Against (say) a circular fortification with a radius of 80yd, with moderately heavy gun defences, a Staffel of Ju87s stood a good chance of scoring four or five hits with large bombs.
In each case the nature of the target dictated the bomb load carried by the Ju 87; against a concreted fortification, for example, a single SD-500 would be used; against field artillery positions, a typical load would be one SC-250 under the fuselage and four SC-50s under the wings (the designation of a German high explosive bomb indicated the type of casing and the weight of the weapon in kilos).
When approaching their target the Ju 87s would, typically, fly in three-aircraft Vics (Ketten) at about 15,000ft, cruising at 150mph. Larger formations would be made up of several of these Vics in line astern, with a spacing of about 300yd between aircraft, up to a usual maximum of about 30 machines (Gruppe strength). If there were fighters flying close escort, these would follow a weaving path behind and slightly above the dive-bombers; as the force neared the target the escort would split, one-third remaining at height while the remainder descended to about 3,000ft to be in position to protect the bombers from enemy fighters as they pulled out of their dives.
Prior to entering his dive the Ju 87 pilot switched on his reflector sight, trimmed the aircraft for the dive, set the pull-out altitude on the contact altimeter, closed the radiator flaps, throttled back the engine and opened the ventilation air supply to the windscreen (to prevent possible misting as the aircraft entered the moist air lower down). Finally he switched on the wind-driven ‘Screamer’ (if required) and opened the dive breaks; the hydraulic operation of the brakes automatically lowered an elevator tab, to counter the severe nose-up trim-change which would otherwise result.
The signal to attack was given by the formation leader starting his dive. For strikes on smaller targets the aircraft would move into echelon during the approach, and peel off and attack in line astern. Against larger targets (for example, harbours or marshalling yards) the dive-bombers would bunt over and attack by Vics; the pilot was able to see directly beneath his aircraft through a small window set in the floor, and so was able to judge when to begin his bunt.
Once it was established in its dive, typically at an angle of 80°, the Ju 87 with extended dive-brakes gained speed only gradually. It took about 8,000ft for it to reach its limiting speed of about 350mph, after which its velocity remained constant. The accuracy of the attack depended upon the accuracy with which the selected dive angle was maintained. To assist him the pilot had etched lines on the side panels of his canopy, rather like a protractor, on which he could align the horizon and read off his angle; after same practice, however, pilots were able to judge their dive angle to within fine limits without having to resort to this aid.
A dive from 15,000ft to a release altitude of 3,000ft (usual for attacks against defended targets) took about 30sec, during which the pilot controlled his aircraft to hold the target in the centre of his reflector sight.
Four seconds before the dive-bomber passed the pull-out altitude previously set on the contacting altimeter, the latter sounded a horn. When the horn ceased, at release height, the pilot pressed a button on his control column to actuate a powerful spring which returned the elevator trim tab to the neutral position; the aircraft, now in a tail-heavy configuration, began automatically to pull itself out of the dive. The pressing of the button had also started the run-down of the bomb-release distributor, and after a set time interval the bombs were released automatically; the special radius arm swung the fuselage bomb down and clear of the propeller disc.
After the pull-out the pilot regained control and retracted the dive brakes, opened the throttle, trimmed for level flight and made his getaway.