Original subtitles

In 1942 and into 1943,

hundreds of thousands of Americans descend on the East of England

to live, fight, and maybe die in the joint effort

to defeat Nazi Germany from the air.

Combat at 25,000ft, and 300mph,

has never been attempted before.

The physical, mental and emotional challenges will be unique.

Victory in World War II will be largely determined

by who controls the skies:

the German Luftwaffe or the Allied air forces.

All wars changed the world,

but none of them changed the world like the Second World War did.

Japan's on the march, Germany's on the march...

...no-one can imagine the nightmare they're about to unleash...

...the most destructive war in human history.

Suddenly, the world is turned upside down,

and all hell is let loose.

The West is stunned by the speed of the advance.

You get the Allies, led by the big three,

Roosevelt, Churchill, Stalin:

men who are dealing with immensely complicated questions.

It's the biggest military operation of human history.

The Allies have to come together, not just militarily,

but industrial scale: it's a global perspective.

They have to fight in every climate,

from the Arctic, to the jungles of the Pacific,

to the deserts of Africa and the depths of the ocean.

But there was no certainty of victory.

It was going to be a horrific bloodbath.

We see humans at their absolute worst,

how they treat other human beings.

And we see them at their absolute best,

willing to give their lives that others might live.

World War II was a struggle in which

there could be one victor... and one vanquished.

The Third Reich is building

elaborate coastal defences in Europe.

As they continue to battle the Soviets in the east,

the Germans know that it's only a matter of time

before Britain and America attack from the west.

From the English Channel to the plains of Russia,

Germany controls most of Europe.

Hitler has turned Europe

into an apparently impregnable fortress.

But as people said at the time,

'Yes, but he forgot to put a roof over it.'

And the Allied bombers are going to take advantage of that.

In the First World War,

both sides bombed each other to little effect.

But as aviation evolves,

a new concept of warfare develops in the 1920s and 1930s:

strategic bombing.

Its proponents are a group of officers

from the US Air Corps Tactical School.

They come to be known as the Bomber Barons.

The theory is we'll use this novel weapon in a novel way,

not to attack the enemy's armies,

to attack the enemy's homeland:

his factories, his infrastructure, destroying his economy,

and thus making it impossible for the enemy to make war.

These air power advocates say this is a better way to fight war.

No need for that horrible trench deadlock from World War I.

That's the old way.

The new way is strategic bombing.

East Anglia is the England of little churches,

hedges, fields, medieval buildings.

And it's turned...

into one gigantic...

...aircraft carrier.

In the spring of 1942,

the US Eighth Air Force begins construction

on dozens of air bases,

transforming a quiet corner of East England

into one of the most vital fronts of the entire Second World War.

It's flat, it's perfect for airfields.

So you get this massive, massive influx of American bombers...

...carrying the most destructive weapons ever produced.

And just as strikingly, young American airmen.

They all had grown up dreaming of flying above the clouds

at over 300mph...

...something their parents and grandparents could never imagine.

And all of a sudden, here's this opportunity.

The English used to complain, 'They're oversexed,

they're overpaid,

and they're over here.'

The Royal Air Force has been striking

the German homeland for two years.

Take off, off you go. Off you go, over.

Prime Minister Winston Churchill understands

how important such raids are for British morale.

But the RAF pays a grievous cost.

And in these early months of the war,

there were raids with hardly any aircraft coming back.

And the most important lesson they took away from it is that

daytime bombing was a very hazardous thing to undertake.

Arthur Harris is the man

put in charge of Britain's Bomber Command.

And it's his idea to switch to night bombing:

to use night as a cloak

to protect these bomber forces

so that they can drop their bombs

and they have a better chance of making it home.

So what they're doing is merely area bombing.

They're flying over German cities at night

and letting loose their bomb loads.

And that means civilian casualties.

There's a lot of retribution in this British strategy.

The Blitz had smashed British cities

and factories in the winter of 1940-1941.

And the Brits plan to smash German society so badly

that it knocks them out of the war.

They sowed the wind, and now...

they are going to reap the whirlwind.

Meeting in Casablanca,

President Roosevelt, Prime Minister Churchill, and their staffs

strategise how to continue the Allied assault on the Third Reich.

One of the major outcomes of the Casablanca Conference

is the Allies declared unconditional surrender as their war aim.

But something else happens at Casablanca as well...

...an argument on air strategy between the British and Americans.

The US Army Air Force,

particularly its Commander, General Henry 'Hap' Arnold,

insists that daylight precision bombing

on critical wartime industries will be more effective.

And as so often in World War II,

American expectations come up against British experience.

Churchill is gonna go to FDR and tell him that, 'Look.

Your daylight precision stuff, it's not gonna work.

We tried it, it didn't work.

That's why we are doing bombing operations at night.

And that is the way forward.'

Well, Hap Arnold gets wind of this.

Arnold's a pioneer in aviation,

taught by the Wright Brothers how to fly,

and he is a believer in strategic air power.

And when the British say, 'Hey,

you guys should bomb at night just like we do,'

he says, 'No, no, air power could be used in a better way.'

The American plan rests on a cutting-edge device...

...the Norden bombsight.

The Norden bombsight is an analogue computer.

You punch in various data:

wind speed, altitude, wind direction,

air pressure, and it correlates all those things together

and tells you exactly when to drop the bomb.

According to the advertising slogans,

it can drop a bomb in a pickle barrel at 18,000ft.

Americans claimed the Norden bombsight,

which requires daylight and clear weather,

promises greater precision,

and therefore fewer civilian casualties.

So Henry Arnold and his advisors come up with this plan,

the Combined Bomber Offensive,

which means the British bombing at night

and the Americans bombing precision targets during the day.

The Americans are gonna sell it as this round-the-clock bombing.

And this utterly appeals to Churchill,

with the idea that his adversary will never catch a break.

Attacking an enemy from 25,000ft

presents unique challenges.

Temperatures dip below -50F.

If an airman's supply of oxygen is cut off for more than 60 seconds...

...he will die.

You look out the window as a crewman on a B-17,

and you begin to see black puffs.

And they might not look too dangerous...

...until one actually makes contact.

The most infamous German weapon of them all

was the Flak 88mm gun.

It's capable of sending 29lb explosive projectiles...

...to altitudes approaching 30,000ft.

The dilemma with Flak is you can't manoeuvre to avoid it...

...so the best you can do is sit tight and grit your teeth.

Once the Flak stops, there's silence.

It's a deathly silence, because they know what's coming.

There's four of 'em, one o'clock high.

They're coming around.

German fighter pilots are seasoned combat veterans.

Many of them have hundreds of kills

cos they've been engaged in this war since 1939.

The best way to kill a German fighter

is to send Allied fighters to shoot them down,

but when the United States starts to bomb Germany proper,

their fighters don't have the range to be able to escort bombers

all the way to a target.

So the B-17 is bristling with machine guns

around the fuselage of the aircraft.

Three planes, nine o'clock, coming around.

Too fast, six o'clock up, coming in.

It really is a flying fortress.

Bomber crews were these interdependent societies

in which every person was dependent upon

the person sitting next to 'em and the person sitting behind them.

Breaking 11, breaking 11. I got him.

B-17 out of control at three o'clock.

Come on, you guys. Get out of that plane. Bail out.

Come on, get out of there.

A few miles from the actual target,

the bomber will start what's called the bomb run.

It's all done visually.

You have to hold altitude, hold air speed, and hold heading

so the bombardier can dial in on the Norden bombsight.

Cos if you don't hit the target, you gotta come back again.

War sometimes breaks down to individual moments of terror.

You're watching other planes being literally blown out of the sky.

And you have to drop the bombs with precision...

...and then make it out again on the way home.

Bombs away!

In combat conditions, the accuracy of the Norden bombsight

is not as precise as the Air Force predicted.

The casualties are greater than they feared.

These missions would come back with 10%, 20% losses.

And of course, the pilots are highly trained,

highly technical people that are very difficult to replace.

No-one in history has ever tried

strategic bombing on this scale before.

As generals, and strategists, and air marshals are working out

the future of air war, these men are guinea pigs.

Mission by mission, the Eighth Air Force slowly develops

the methods needed to damage their intended targets.

But Adolf Hitler's attention remains fixed

on his battle with the Soviets.

He had seen the German losses back in 1940

when the Luftwaffe was attacking England.

And to him it looked like...

strategic air power doesn't win wars, ground forces win wars.

So Hitler's viewpoint about an air force is that it exists...

to support the ground troops.

With the loss at Stalingrad,

including the capture of his entire 6th Army,

Hitler is focused on the Eastern Front.

But the Allied raids do alarm

Luftwaffe Air Marshal Hermann Goering.

Goering is hearing from his local and regional

Luftwaffe commanders that they really need more fighter aircraft.

But in a sense, Goering's trapped.

If he detaches air power from the Eastern Front,

a situation that is already critical is soon going to turn mortal.

The Germans now are gonna streamline procedures...

...and make things more efficient.

They start producing more aircraft, more armaments...

...in the middle of the Combined Bomber Offensive.

So from 1943 on,

there's an exponential increase in German industrial output.

With German fighter production on the upswing,

the Allied governments are becoming increasingly concerned,

and they're getting a little tired of hearing their airmen say,

'We can bring Germany to its knees,'

when they don't see any evidence that that's true.

In May, Churchill and Roosevelt meet

to finalise plans in the Mediterranean.

They also commit to a cross-channel invasion of France.

Since America came into the war, they've had a strategy...

to land a gigantic force somewhere in northwestern France...

and then driving straight into the heart of Germany.

Codenamed Operation Overlord,

the attack is scheduled for spring of the next year.

Achieving air supremacy over occupied Europe

is crucial to the success of the invasion.

At this point, everybody recognises amphibious operations can't happen

unless you control the seas and have control of the air.

So the top commanders all agree that the number-one priority

is destroying the Luftwaffe.

And that means the bomber force is given the job

of smashing the infrastructure of the Luftwaffe on the ground...

...so when the Allies land on D-Day and in the ground fighting

that follows, there'll be no German aircraft interfering.

The RAF and Eighth Air Force join efforts

for what they term Blitz Week:

attacks on various cities across Germany.

Their first joint target is a busy port with dockyards,

submarine pens and manufacturing.

It's also a home to over a million people.

Hamburg is a real centre

of aircraft production, so for the Americans,

there's lots of specific military industrial targets they can attack.

But the Brits look at the types of housing there and they think

they're very vulnerable to fire.

So they're going to burn neighbourhoods.

They're gonna de-house German people.

And that means workers are gonna be killed,

factories will grind to a halt, supply chains will break down.

It's codenamed Operation Gomorrah,

after the Old Testament city that was destroyed by fire from above.

This is gonna be eight days and seven nights

of pounding the city of Hamburg.

It's very carefully planned.

First, there are high explosives to blow out windows,

to blow out roofs, to knock down buildings.

And they'll drop incendiaries, smaller bombs,

that just burn like firecrackers, and with these roof tiles gone,

the wooden structure of the roofs is exposed.

These little incendiaries will land in those roofs and just set fires.

The British want revenge on Hamburg for the Blitz.

The Americans have been singing the strategic bombing song for years,

and now they can show the destructive nature...

of the Combined Bomber Offensive...

to wipe a city off the map.

In the summer of 1943...

...Allied air forces launch Blitz Week...

...the largest series of raids on Germany to date.

The British and American air forces

have supposedly been working together:

the British bombing by night, the US by day.

But they haven't been bombing the same target cities.

That changes in the summer of 1943.

The Allies' first joint target is the city of Hamburg.

On the night of July 24th, the raids begin.

The RAF drops incendiary bombs.

But in the following days,

American B-17s are unable to hit their targets.

The Americans intended to bomb aircraft factories,

but the use of incendiaries created so much smoke

that the Norden bombsights were essentially blinded.

They can't actually see their targets, so they're almost

reduced to doing area bombing, not unlike the British.

On July 27th,

a heat wave sends temperatures soaring

as the RAF returns for a fourth night of strikes.

It's very hot, it's very dry.

And the meteorological conditions are ripe for firestorm.

This time, the fires burn so hot,

the oxygen that these fires demand causes a windstorm.

Winds are over 150mph.

The firestorm works a little bit like a blast furnace.

It's a localised weather system that will see that fire spread

at the speed of a galloping horse.

A gigantic updraft results,

that robs people cowering in their shelters of oxygen

and leads to death by asphyxiation.

Temperatures go up to 1,000C.

It's the most devastating firestorm that's ever been created.

Stories are of people trying to run out of shelters

with children near them,

burning, with their hands and feet stuck in melting asphalt,

with the buildings falling down on top of them.

The city of Hamburg...

...is devastated.

Operation Gomorrah kills over 40,000 civilians.

Almost two-thirds of the city's houses are burnt to the ground...

...leaving a million residents homeless.

Churchill is worried about the human cost of what they're doing.

He's worried about how history will look at it.

And there's a line from Churchill supposedly,

where he looks at some of the movies of Hamburg...

...and goes, 'Are we beasts?'

The striking thing about air power...

is it makes all of us combatants.

It's not just about the battlefield.

The battlefield is actually civilian populations.

The destruction stuns Nazi high command.

One of Hitler's ministers tells him that,

'Hamburg put the fear of God in me.'

But Hitler refuses to visit the city

or receive a delegation of civilians who had saved lives during the fire.

Hamburg is a shock to the entire German war effort.

Goering has told Hitler, repeatedly,

that he had this bomber problem under control,

and now here lies the second-largest city in Germany in ashes.

Accounts of the bombing of Hamburg spread throughout Germany.

Hitler begins to transfer German fighter planes

from the Eastern Front and the Mediterranean to the fatherland.

In addition, the Germans ring their major cities

with these gigantic, monumental Flak towers.

150ft tall,

11ft-thick concrete walls,

bristling with guns.

Not only are they highly effective against incoming bombers,

their guns barking the sound and fury

remind the people that Hitler is looking out for them.

Back in Britain, there was big disagreement,

at the time, with how the raid on Hamburg goes.

From Harris's point of view, this is a war-winning strategy:

that if you hit people hard enough,

you can cause a breakdown of their will to fight.

But for Arnold, Hamburg was not a success.

It proved the inefficiency of area bombing.

He wants to strike precise targets:

the factories that are keeping the Luftwaffe in the air.

Henry Arnold thinks strategic bombing can work.

We just need to do it harder.

The combined American-British raid on Hamburg levels a city...

...but does little to destroy the Luftwaffe

before the invasion of Europe.

By August of 1943,

the Eighth Air Force is receiving enough planes and personnel

to launch the large formations required

to decimate German aircraft production.

Bomber Baron theory is about to be put into practice.

What is keeping the Luftwaffe in the air are the factories behind it.

That's what Arnold wants to strike.

And he thinks the way to do that is to double down

on daylight precision bombing:

more planes, more raids,

more attacks on the same target...

until the Germans break.

Arnold now demands maximum effort from the Eighth Air Force.

Normally, there are planes that are being worked on,

or repaired, or air crew that are resting,

so that every now and then, they get a day off.

But now when you go maximum effort,

it means you put everything in the air every time.

Previously, around 90 B-17s would fly each mission,

but that number will soon double...

and triple.

The Americans are obsessed with this view

of the German economy as a series of interconnected hubs and spokes.

So if they hit the right domino, they'll all come down.

These are called bottleneck industries...

...industries where just a few plants

and locations control all the production.

Bombing bottleneck targets

seems to be a more efficient use of your air force.

One big raid, one factory destroyed,

a crucial sector of the German war economy crippled.

Probably the most consequential bottleneck industry

with regards to the Luftwaffe...

...is ball bearings.

Anything that moves needs a ball bearing.

Anything that turns needs a ball bearing,

including German aircraft engines,

propellers turning, landing wheels,

and also all the machines and machinery that build those products.

So it's a twofer.

On August 17th,

one year to the day from their first attack on occupied Europe,

the Eighth Air Force launches a dual raid.

The first strike on Regensburg

is meant to draw off German fighters

so that the rest of the force can hit the primary target,

Germany's largest ball bearing factory in Schweinfurt.

Three weeks later, the Eighth strikes another plant in Stuttgart.

In these raids alone,

the Eighth loses nearly a hundred planes,

and a thousand crew killed or captured.

Ball bearing production is interrupted...

...but only temporarily.

The Allies are always surprised at how rapidly

the Germans rebuild their cities and factories.

But they do so with this

almost inexhaustible supply of slave labour...

...prisoners of war in the hundreds of thousands.

They're barely fed.

When one dies, they can be simply discarded

and another one put in their place.

Forced labourers from occupied countries

are ordered by the Nazis to reconstruct German factories.

They also dispersed the German aircraft industry...

...so that it can't be taken out in any one strike

cos it's not all in one place.

And they put it underground.

They used old salt mines.

They used old quarries.

Now you can't hit it. Now you can't bomb it.

There is nothing you can do.

Because you can't bomb a facility when it's underground.

This ultimately means German aircraft production

will continue to increase.

By the fall of 1943,

the Eighth Air Force is bombing targets deep inside the Reich

and returning to ones they've already hit.

In early October,

they fly a series of maximum effort raids,

including a second strike on the plant in Schweinfurt...

...all in a single week.

There is a limit to how much the human psyche can take.

And on many occasions, bomber crews reach that limit.

You're five miles up, and you're braving death every second.

Fighters, Flak, fighters, Flak:

an adrenaline rush overloading your nervous system.

And then you land.

And it's quiet.

You're back at a base in East Anglia.

You have a hot meal.

You sleep in a comfortable bed.

And then, maybe, you do it again tomorrow.

More fighters, more flak.

You'd think you were gonna die...

ten times in the course of this bomb raid.

And that night, you'd be drinking Scotch

with a couple of friends at the commissary.

It was almost impossible to reconcile.

The longer you did it,

you would become more and more aware of how vulnerable you were.

By the end of the month,

the Eighth Air Force has endured horrific losses.

The men call it...

Black October.

If you're an American airman,

you have a 20% chance of being killed on any mission you undertake.

One in five: that is forbidding math.

Adding to that, they don't appear to be having an appreciable impact

on the German war effort,

leading to an incipient collapse of airman morale.

They start to see the losses around them and go,

'We're just gonna fly until we're dead.'

A series of American raids in Black October

shows the cost of daytime precision bombing.

The loss rates, the limitations of the Norden bombsight,

the weather: all these things play in, and factor in

how ineffective the bombing campaign is in 1943.

You could easily say that the Luftwaffe

still owned the skies over Germany.

In the late fall, bad weather forces the Eighth Air Force

to suspend missions,

giving ground crews the winter to patch battered planes.

But the RAF launches its largest campaign yet...

...a sustained assault on Berlin.

These are gonna be massive raids, 16 of them in the heart of Germany.

The British goal over Berlin...

is to destroy German morale.

That's the way to beat Germany, not to destroy individual factories.

Harris thinks these Berlin raids will cost 400 to 500 bombers,

but they'll cost Germany the war.

The RAF winter raids to Berlin...

...push the limit and stamina of British air crews...

...with modest results.

Harris is presciently accurate.

They lose 400 to 500 aircraft

and almost 5,000 airmen.

The Berlin bombing campaign is an epic effort...

...but unfortunately an epic failure.

Both air forces are finding their plans

are not corresponding with reality.

They're having almost no impact on the Luftwaffe at all.

They're simply getting more of their planes shot down

and more of their crewmen killed or captured.

After months of heavy losses,

the Eighth Air Force is at a crossroads.

Arnold realises the bombers can't do it alone.

If he wants these bombers to make a difference in this war,

he's got to send fighters to the target with them.

The Allied air forces have the P-38 Lightning...

...and the P-47 Thunderbolt...

...two absolutely excellent fighter aircraft

...capable of dogfighting just about as well as anything else in the sky.

They only had one limitation, and that was range.

At the time, aeronautical engineers believed

having an aircraft that could fly almost a thousand miles,

into Germany and back, with enough firepower,

enough manoeuvrability, enough engine power...

is an engineering impossibility.

But a new fighter is already being produced

by the United States... for the British...

...the P-51 Mustang.

And the Brits test fly it, and they go,

'Thanks. It's OK.'

Below 15,000ft, it's fine,

but we're looking for something higher altitude.

Then we get the idea of putting

a Rolls-Royce Merlin engine in this thing.

So you have a British-made engine,

an American airframe, made it together, and it's gangbusters.

That's when it turns into this magical machine.

It's fast, it flies high.

It's so efficient that it could escort a bomber

all the way to downtown Berlin and back.

It's the equivalent or better than anything the Germans have.

The Americans and British are allies,

but in many ways, they've been working at cross purposes,

especially in the air campaign.

But now the US and British war efforts come together

to produce an aircraft that is greater than the sum of its parts.

It embodies the Anglo-American coalition in World War II.

The P-51 is a game-changer,

but it requires, mind you, an entire rethink of American aerial doctrine.

Allied planners realised that if they threaten targets

that are essential to the German war efforts,

and force the Germans to send up fighters to protect those targets...

...the P-51s can pounce and shoot them down.

The Allies have started out thinking B-17s...

will destroy the German air force on the ground.

By early 1944, they realise the P-51...

...is going to destroy the German air force...

...in the air.

Knowing that command of the air is crucial

to the upcoming cross-Channel invasion,

Allied air forces launch Operation Argument,

a five-day series of bombing raids over major German cities.

This is the critical hour for the Combined Bomber Offensive.

Because the Allies now know they're approaching

the time for the D-Day landings.

They need to draw up the Luftwaffe

so that the P-51 can destroy it in the skies.

The plan is to send thousands of bombers

knowing that the Luftwaffe will have no choice

but to send everything it has up in the skies

to defend the homeland.

So in a way, the bombers are the bait.

Fitted with extra fuel tanks,

the P-51 Mustangs are capable of penetrating deep into Germany.

Their primary mission has been protecting the bombers.

Now they're ordered to actively pursue German fighters...

...even if it leaves the formations vulnerable.

The mission of the American fighters is to be aggressive...

...and go after the Luftwaffe in the air to kill them...

...in any way, shape, or form.

Operation Argument, known as Big Week,

begins a battle of attrition

between the Allied air forces and the Luftwaffe.

The success of the upcoming invasion...

...hangs in the balance.

The United States is gonna lose about

a quarter of the Eighth Air Force in that fight.

The Germans are gonna lose about a third of their fighter force

and 18% of their fighter pilots.

This is something the Allies can sustain.

The Germans cannot.

From the US perspective,

this is a war economy that is churning out hundreds and hundreds

of heavy bombers every day of the year.

Young men are signing up in droves.

And so the cold-blooded calculation is...

that no matter how heavy US losses are,

America can replace its planes and pilots.

In the month after Big Week,

American fighters down more German planes over Europe...

...than in the previous two years.

The Luftwaffe is being destroyed in the air and on the ground.

It's really this symbiosis.

Mustangs, they're killing German fighters,

which means the bombers can now be more accurate.

Which means they're doing a better job of attacking...

the German aircraft industry.

It's a cycle that's destroying the Luftwaffe.

By June 1944,

there are few experienced Luftwaffe pilots...

left alive.

By the time the D-Day comes, the Allies own the air.

That's why you see very few Luftwaffe fighters

over the beaches of Normandy on June 6th 1944.

Control of the air is decisively established.

The Luftwaffe will be incapable of opposing

the upcoming Allied invasion.

But again, the cost is high.

Fewer than a quarter of British and American bomber crews

survive the campaign.

The tragedy of the air war is that the bomber crews

were essentially testing out an unproven theory.

Any time you're talking about high technology,

and cutting-edge weaponry,

there is an element of experimentation involved.

And some of the ways, unfortunately, that you learn in war...

is by dying.

Sometimes in wartime, there's no other way to learn.

When both the British and American air forces worked together,

bombers and fighters together,

they proved to be the most effective aerial instrument of war in history.

The battle in the air over Europe isn't won by B-17s or P-51s.

It's won by the men who fight in those planes,

and the men and women who support them on the ground.

What they accomplish, the destruction of the German Luftwaffe,

will make possible the greatest land and sea invasion in history.