The Junkers JU 87 or Stuka was the German dive bomber and ground-attack aircraft. Designed by Hermann Pohlmann, it first flew in 1935. The JU 87 made its combat debut in 1937 with the Luftwaffe’s Condor Legion during the Spanish Civil War and served the Axis forces in World War II.
The aircraft is easily recognisable by its inverted gull wings and fixed spotted undercarriage. Upon the leading edges of its faired main gear legs were mounted the Jericho-Trompete wailing sirens, becoming the propaganda symbol of German air power and the so-called Blitzkrieg victories of 1939–1942. The Stuka’s design included several innovations, including automatic pull-up dive brakes under both wings to ensure that the aircraft recovered from its attack dive even if the pilot blacked out from the high g-forces.
The Ju 87 operated with considerable success in close air support and anti-shipping at the outbreak of World War II. It led air assaults in the invasion of Poland in September 1939. Stukas were critical to the rapid conquest of Norway, the Netherlands, Belgium and France in 1940. Sturdy, accurate, and very effective against ground targets, the Stuka was, like many other dive bombers of the period, vulnerable to fighter aircraft. During the Battle of Britain, its lack of manoeuvrability, speed and defensive armament meant that it required a heavy fighter escort to operate effectively.
Flying at 15,000 ft, the pilot located his target through a bombsight window in the cockpit floor. The pilot moved the dive lever to the rear, limiting the “throw” of the control column. The dive brakes were activated automatically, the pilot set the trim tabs, reduced his throttle and closed the coolant flaps. The aircraft then rolled 180°, automatically nosing the aircraft into a dive. Red tabs protruded from the upper surfaces of the wing as a visual indicator to the pilot that, in case of a g-induced black-out, the automatic dive recovery system would be activated. The Stuka dived at a 60–90° angle, holding a constant speed of 350–370 mph due to dive-brake deployment, which increased the accuracy of the JU 87’s aim.
When the aircraft was reasonably close to the target, a light on the contact altimeter an altimeter equipped with an electrical contact which triggers at a preset altitude came on to indicate the bomb-release point, usually at a minimum height of 1,480 ft. The pilot released the bomb and initiated the automatic pull-out mechanism by depressing a knob on the control column. An elongated U-shaped crutch located under the fuselage swung the bomb out of the way of the propeller, and the aircraft automatically began a 6g pull out. Once the nose was above the horizon, dive brakes were retracted, the throttle was opened, and the propeller was set to climb. The pilot regained control and resumed normal flight. The coolant flaps had to be reopened quickly to prevent overheating.
Physical stress on the crew was severe. Human beings subjected to more than 5g in a seated position will suffer vision impairment in the form of a grey veil known to Stuka pilots as “seeing stars”. They lose vision while remaining conscious; after five seconds, they black out. The JU 87 pilots experienced the visual impairments most during “pull-up” from a dive.
After the Battle of Britain, the Stuka was used in the Balkans Campaign, the African and Mediterranean theatres and the early stages of the Eastern Front, where it was used for general ground support, as an effective specialised anti-tank aircraft and in an anti-shipping role. Once the Luftwaffe lost air superiority, the Stuka became an easy target for enemy fighter aircraft. It was produced until 1944 for lack of a better replacement. By 1945 ground-attack versions of the Focke-Wulf Fw 190 had largely replaced the JU 87, but it remained in service until the end of the war. An estimated 6,500 JU 87s of all versions were built between 1936 and August 1944.