The Stuka is the sound of the first year of the war. In Poland, Norway and France it flew ahead of the tanks as artillery that could be anywhere in minutes: it rolled over, pointed its nose almost straight down at a bridge or a gun position, and released its bomb from a few hundred metres up. It was slow, and once the fighters it needed were gone it was shot out of the sky over England — but it fought to the last day in the East, and for one year it changed how wars were fought.
410 km/hTop speedup to 1,800 kgBomb load
2· WHY IT MATTERED
Accuracy from a dive, not a bombsight
Level bombers of 1939 missed by hundreds of metres. A Stuka pilot lined the target up through red lines painted on his canopy at 60°, 75° and 80°, and dived at it: the bomb left the aircraft already pointed at the target, and hit within tens of metres. That is why a squadron of them could take out a bridge the whole artillery had missed.
Pulling out of a 550 km/h vertical dive takes about 6 g, enough to grey a pilot out. So the Stuka did it itself: pressing the bomb release also triggered an automatic pull-out through the elevator trim. A contact altimeter lit a lamp at the preset release height — around 450 metres at the lowest — because below that there was no room left to recover.
4· WHY IT MATTERED
Only as good as the air around it
At 400 km/h with a fixed undercarriage the Stuka was easy meat for a Spitfire or a Hurricane, and the Battle of Britain stopped its daylight career in the West within weeks. In the East, where the Luftwaffe kept air superiority longer, it went on — the Ju 87 G with two 37 mm cannon became the most effective tank-killing aircraft of the war in the right hands.
5· THE ENGINE
An inverted V-12 that could fly upside down
The Jumo 211 hangs its twelve cylinders below the crankshaft — an inverted V — which gave the pilot a better view over the nose and made the guns and exhausts easier to package. More important for a dive-bomber, it was fuel-injected from the start: a carburettor engine coughs or cuts when the aircraft rolls inverted and the float chamber empties, and the Stuka rolled inverted into every attack. A two-speed supercharger gave it one gear for low altitude and one for high, the simplest way of matching an engine to the thin air it breathes higher up.
Junkers Jumo 211J · inverted V-12 · 35.0 L · direct injection · two-speed supercharger · 1,400 hp
The Stuka B carried one 250 kg bomb under the fuselage and four 50 kg bombs under the wings; the later D took a single 1,000 kg bomb. Its two forward machine guns fired about 0.5 kg of bullets a second between them — nothing by fighter standards — and the gunner behind had a twin gun for the fighters that would come. The famous siren, a small propeller-driven whistle on each leg, cost 20–25 km/h and crews often took it off. The Ju 87 G swapped the bombs for two 37 mm cannon with tungsten-cored shells, six rounds each side, and went hunting tanks.
7· TRY IT
Its engine, live: 1,400 hp against thin air
The lab runs the Jumo 211J’s two-speed supercharger against the atmosphere: the power it makes falls as the air thins, jumps when the blower changes gear, and the aircraft’s speed follows. The Stuka rarely climbed high — the dive started from 4,000 m or so — which is why two gears were enough.
Readout
Power1,253 hp
Per engine1,253 hp
True airspeed410 km/h
Service ceiling7,300 m
A simplified model calibrated to the published rating and top speed — the shape of the curve is the point, not the third decimal.
Junkers Ju 87 Stuka, 1 of 10
Deep dive · How dive-bombing works· opened from Junkers Ju 87 Stuka
Timelines · WW2 aircraft · go deeper · Junkers Ju 87 Stuka
How dive-bombing works1939
Point the whole aircraft at the target, let go, and survive the pull-out — the machine did the last part for you.
500–600 km/h·60–90°·6 g, automatic·~450 m
01The idea
An 80° dive from 4,000 m, release at 450 m, a 6 g pull-out that eats 400 m of sky
A bomb dropped from level flight keeps the aircraft’s forward speed and falls in a long curve; a small error in speed or timing is a big error on the ground. A bomb released in a steep dive is already travelling towards the target, so most of the error disappears. The price is the pull-out: the aircraft must turn from pointing down to pointing along the ground, and that turn costs height, g and, if the pilot has misjudged it, the aircraft.
02Why it matters
The geometry of the dive
Dive brakes under the wing held the Stuka at 500–600 km/h so that it did not accelerate past the speed the wings could stand. The pilot lined up red lines on his canopy — 60°, 75°, 80° — with the horizon to read his dive angle, and the bomb, swung out on a crutch so it cleared the propeller, left along the line he was looking down.
03Why it matters
The pull-out costs 400 metres
A turn at speed v pulling n times gravity has a radius r = v²/(g(n−1)). At 550 km/h and 6 g that is about 480 metres, and turning from an 80° dive to level loses roughly 400 metres of height. So the contact altimeter was set to light at about 450 metres: any lower and the arithmetic said the aircraft would meet the ground before it was level.
04Why it matters
The pilot was not trusted with it
At 6 g a seated pilot’s vision greys and then goes; some blacked out completely. So pressing the bomb release also triggered an automatic pull-out through the elevator trim, and the aircraft recovered on its own while the pilot came round. It is one of the first examples of a machine flying the manoeuvre because the human could not.
05Try it
The dive, live
Choose the dive angle, speed and pull-out g and see where the bomb goes and how much sky the recovery needs.
Readout
Pull-out radius476 m
Height lost levelling off393 m
Lowest point57 m
Bomb’s fall2.7 s, 73 m forward
Above about 5 g the pilot greys out — which is why pressing the release button started the pull-out automatically. No drag on the bomb; real ones fell a little shorter.