Junkers Ju 87 Stuka

The idea behind the Ju 87 was older than the aircraft itself. Through the 1920s and early 1930s a handful of airmen — among them the American naval pioneers and, in Germany, the First World War ace Ernst Udet — became convinced that a bomber which plunged almost vertically onto its target could place its bombs with a precision no level bomber could match. Udet, smitten after watching American Curtiss dive-bombers, became the idea's most powerful champion within the rebuilding Luftwaffe, and the Sturzkampfflugzeug — "dive battle aircraft", contracted to Stuka — was written into German doctrine.

Junkers’ answer was designed by a team under Hermann Pohlmann, and the first prototype was not built in Germany at all. The Ju 87 V1 airframe came from AB Flygindustri, the Junkers subsidiary in Sweden that existed to keep work beyond the reach of the Versailles inspectors. It flew on 17 September 1935 with Hauptmann Willy Neuenhofen at the controls, carrying a twin tail and a British Rolls-Royce Kestrel V12, because no suitable German engine was ready. It crashed on 24 January 1936 at Kleutsch, near Dresden.

What came out of the redesign was deliberately unlovely: angular and slab-sided, with an inverted-gull wing and a massive fixed, trousered undercarriage. Speed and elegance were traded away for the one quality that decided everything — the structural strength to be thrown at the ground at 70 degrees and pulled out again, hundreds of times, without breaking up.

What made the Stuka deadly was not performance but a sequence of mechanisms that turned dive-bombing from a stunt into a repeatable procedure. The pilot pulled the dive lever, which extended the dive brakes and trimmed the aircraft into its plunge; he set the angle against a scale of red lines etched into the right-hand canopy panel, matched against the horizon. A contact altimeter, the Fl.22317, was pre-set to the release height and lit a signal lamp on reaching it. Pressing the release knob on the control column let the bomb go and triggered the recovery: the aircraft pulled itself out at about 6 g, and needed roughly 450 m of air beneath it to finish the manoeuvre.

Two further details made the system work. A crutch under the fuselage swung the bomb down and clear of the propeller arc before release, which is what allowed a near-vertical dive without the aircraft shooting off its own airscrew. And the automatic pull-out kept working when the pilot greyed out under the g-load, which happened often enough that the mechanism rather than the man is what made steep dive-bombing repeatable. Against bridges, ships, gun positions and strongpoints the result was an accuracy no level bomber of 1939 could approach.

The Jericho-Trompete was a propeller-driven siren on the undercarriage legs whose shriek rose with the dive, and it is the single best-known thing about the aircraft. It was a deliberate weapon against morale rather than against material, and it cost something real: the drag of the sirens took roughly 24 km/h (15 mph) off a machine that had none to spare.

It is worth correcting the most repeated image of the type. The screaming Stuka over southern England in 1940 did not happen: the sirens had been coming off since the spring of that year, and on the evidence of the aircraft brought down over Britain, none of the Ju 87s that fought the Battle of Britain carried them. What replaced the effect was cheaper — whistling devices screwed to the bombs themselves — so the noise that a generation remembers was frequently the ordnance falling rather than the aeroplane diving.

The war’s first bombing attack is usually reckoned to be a Stuka mission, and it failed. At 04:26 on 1 September 1939 a Kette of three Ju 87 B-1 of 3./StG 1 under Oberleutnant Bruno Dilley took off against the bridges at Dirschau (Tczew) on the Vistula. The target was not the bridge but the Polish demolition charges and the cables running to them, a job that needed precision to the metre and existed only because the Stuka was thought able to deliver it. The bombs fell at 04:34. Polish engineers repaired the cables and blew the bridge before the German troops arrived.

What followed across Poland, the Low Countries and France in 1939–40 justified the doctrine anyway. The Stuka worked as flying artillery for the panzer columns, called down onto fortifications, road junctions and columns of retreating troops, and delivering with a single aircraft what a battery could not bring up in time. It was the visible instrument of the Blitzkrieg, and it did that work in a sky in which the Luftwaffe met nothing that could reach it in numbers.

The condition failed over England. The Stuka was slow, weakly armed and, at the bottom of a dive, heavy and committed with nowhere to go; against Hurricanes and Spitfires flown by pilots who knew where to wait, it was butchered. Between 12 and 18 August 1940 the Luftwaffe lost 41 Ju 87. On 18 August, the day the RAF calls the Hardest Day, StG 77 lost seventeen aircraft attacking the airfields at Ford and Thorney Island.

Across the ten days from 10 to 18 August, more than twenty per cent of the entire Stuka force committed to the battle was destroyed. Göring withdrew the type from daylight operations over Britain, and the aeroplane that had been the symbol of German victory for eleven months was taken out of the decisive air battle of the war after six weeks of it.

In the Mediterranean the Stuka got the conditions back, and gave the clearest demonstration of what its accuracy actually meant. On 10 January 1941, about 75 miles west of Malta, roughly 40 Ju 87 of Fliegerkorps X attacked the armoured carrier HMS Illustrious, manoeuvring at speed and defended by her own guns and fighters. They hit her six times with 550 kg bombs. Three of those went through the flight deck and burst in the lower hangar among aviation fuel, torpedoes and bombs.

The ship survived because her deck was armoured and reached Malta under her own power, but she lost 126 men killed and 91 wounded and was out of the war for a year. Six hits out of forty aircraft on a warship under way, at a moment when level bombers were routinely missing stationary targets, is the number that explains why the Luftwaffe kept the type in production long after it had stopped being survivable.

The Ju 87 A was the first service version and the smallest run: 262 were completed by mid-1938, 192 at Junkers in Dessau and 70 at Weser Flugzeugbau at Lemwerder. It was underpowered, and it was the first mark sent to Spain with the Condor Legion, where the doctrine was tested on somebody else’s country before it was used on Poland.

The B was the definitive early-war machine and the one that flew over Poland and France — 922 built, 697 B-1 and 225 B-2. The R that followed was the same aeroplane rebuilt for reach, trading bomb load for fuel in wing tanks and underwing drop tanks so it could work over water: 972 were built, all of them by Weserflug, and they did the anti-shipping work in Norway, off Malta and around Crete.

The popular image of the Stuka is an aircraft of 1939 and 1940. The production figures say something else. The Ju 87 D — the Dora, with the more powerful Jumo 211J, a cleaned-up cowling and radiator, better armour for the crew and a bomb load rising to 1,800 kg — ran to 3,639 aircraft: 592 D-1, 1,559 D-3 and 1,448 D-5. That is roughly three out of every five Ju 87 ever completed, and every one of them was built after the Blitzkrieg years the type is remembered for.

They were built for the Eastern Front, where the Soviet fighter arm was for a long time not able to be everywhere at once, and where a slow aircraft that could put a bomb on a bunker still had work. When even that stopped being possible, the airframe moved into the dark: the D-7 and D-8 were night ground-attack machines with flame-damped exhausts, flown by the Nachtschlachtgruppen against Soviet supply columns until the last weeks of the war.

The last combat version turned the dive bomber into a gun platform. The Ju 87 G carried two BK 3,7 cannon in underwing pods, the airborne adaptation of the 3.7 cm Flak 18, firing tungsten-cored AP at over 850 m/s from six-round clips in twelve-round magazines. It could put 58 mm through armour at 100 m against plate at 60° — against a T-34’s 40 mm flanks that was enough, against its 90 mm effective glacis it was not, which is why the doctrine was to attack from the side or the rear at under 400 m, with Ju 87 D suppressing the anti-aircraft guns first. Around 208 G-2 were built new and further aircraft converted from D airframes.

The G is inseparable from Hans-Ulrich Rudel, and his figures need stating carefully. The Luftwaffe credited him with 519 tanks, 70 assault guns and more than 800 other vehicles across 2,530 sorties, and no other pilot in any air force comes close to that record. But ground-attack claims were not verified the way air-to-air victories were: there was no mandatory gun-camera confirmation, the wrecks lay on ground that changed hands, and the claim rested on the pilot’s own report and his wingman’s. Modern assessments suggest he destroyed somewhere between 50 and 75 per cent of what he was credited with. Even the bottom of that range leaves him the most destructive ground-attack pilot of the war.

Adding the marks together gives about 6,000 aircraft — 262 A, 922 B, 972 R, 3,639 D and roughly 208 G — and published totals run from about 5,700 to over 6,500. The spread is the usual one: authors count contracts, completed airframes and conversions from earlier marks differently, and a G rebuilt from a D-3 can be counted once or twice depending on the ledger being used. Production ended in August 1944.

For three years the Ju 87 was the most accurate striking weapon in the world, and its whole value depended on a condition it could not create for itself. Given control of the air it could put a bomb through a carrier’s flight deck; denied it, a fifth of the force could be destroyed in ten days. The aeroplane did not change between August 1940 and January 1941 — the sky above it did.

• Peter C. Smith, Junkers Ju 87 Stuka (Crécy Publishing).
• Manfred Griehl, Junkers Ju 87 Stuka (Airlife).
• John Weal, Junkers Ju 87 Stukageschwader 1937–41 (Osprey, Combat Aircraft).
• Hans-Ulrich Rudel, Stuka Pilot — the memoir of the war’s most-decorated Stuka flier.
• Peter C. Smith, Junkers Ju 87 Stuka (Crowood Aviation Series) — development, the dive system and the marks.
• John Weal, Junkers Ju 87 Stukageschwader of North Africa and the Mediterranean (Osprey Combat Aircraft).
• Hans-Ulrich Rudel, Stuka Pilot — the participant memoir behind the 519 tanks, to be read as a claim rather than a record.