What Happened to the Hindenburg?

COMM
For a full decade earlier this century, one form of transportation was considered the fastest, most technologically advanced and most luxurious of its day.

RADIO COMMENTATOR

We are greeting you now from the Navel
Airbase at Lakehurst New Jersey from which point we are going to bring you the description of the landing of the mammoth airship Hindenburg.

If bursts into flames, its tragic, get this Scotty, get this Scotty, It's fire Ed, it's crashing, its crashing terrible, . . . this is terrible, this is one of the worst catastrophes in the world . . .all the humanity, all the passengers screaming around me. I can't talk ladies and gentlemen.

COMM
In just 34 seconds the golden age of airship travel was ended by the fireball that engulfed the Hindenburg, killing 35 passengers and crew.

The hydrogen that gave the ship its lift has always been blamed for the tragedy. But a startling new theory has emerged.

Former NASA hydrogen specialist Addison Bain has been investigating the cause of the disaster, using modern techniques that were not available during the initial inquiry. After nine years, he is confident he has the hard evidence to prove his theory.

ADDISON BAIN
Well the prevailing theory for 60 years


was first that free hydrogen got lose and mixed with the air, and then that there was a source of ignition, and that's the theory that's persisted. But I think it's much more than that, much more deeper than that, and I do believe that they knew that within a couple of months after the accident.

COMM
The LZ 129 Hindenburg was the pride of Nazi Germany. Nearly 820 feet long, she was the largest aircraft ever built, just 82 feet shorter than the Titanic.

She was the world's first intercontinental passenger airliner, the most sophisticated airship built by the Zeppelin Company.

JOHN PROVAN
AIRSHIP HISTORIAN
The Hindenburg was really the epitome of German technology at that time, it was an airship really designed to carry passengers with a certain amount of luxury and comfort, it was the concord of the period if you will.
That is why do people spend money on getting the concord- it's to get somewhere fast. That's what the Hindenburg was all about. It was the fastest means of sending passengers and mail to the United States and to South America.

COMM
In New York City, there were even plans to dock airships to the top of the Empire State Building.

A gangplank hundreds of feet up in the air, combined with unpredictable high winds, made the idea impractical, but some primitive fly-by mail pickups were attempted.

With the jet age still some years away, airship travel was unique in its ability to combine speed with comfort.

HEP WALKER
You take off in an airship, you're just sitting there and the ground just drops away from you, completely opposed to an aeroplane where you're going down the runway with seatbelts on gripping your seat. In an airship you're completely relaxed. Passengers going to Europe a lot of times they'd go down to the cabin to get freshened up, and then they ask the cabin steward what time the airship was gonna take off, they say: Well we're over New York, we took off twenty minutes ago!

JOHN PROVAN
The type of people to fly on the Hindenburg were probably very much the same type of people who would take a ride on the Titanic. It was the wealthy, the well-to-do the flight cost approximately 1400 DM which was about the price of a volkswagen and a half so that gives you a price comparison in today's terms if you will.

EDITH DIECKMANN
(speaking in German)
TRANSLATION: We were completely overwhelmed by the ship - we hadn't realised that we would be boarding a flying hotel. We were very conscious that this was a unique and magnificent experience that might never come again.

COMM
The Hindenburg could carry up to 72 passengers on her luxurious living decks. Flying at speeds of up to 84 miles an hour, she could complete the trip from Germany to America in two and a half days-twice as fast by boat.

HEP WALKER
AIRSHIP HISTORIAN
I was 18 when I saw the Hindenburg. I remember it like it was yesterday. She was flying at about 300-400 foot altitude. The traffic was stopped for a stop light and I had my convertible, I had my top down. The stoplight went red three or four times and nobody moved, they jumped out of their cars just staring at this, you could see the passengers waving and the crewmen, you see a big thing like that and you think it's hardly believable it can be flying, floating in the air just like a cloud/ majestic and beautiful.

VERNA THOMAS
The Hindenburg was gorgeous; it was a beautiful ship, sleek and everything and the people and everything in it were so beautiful. Of course it was Hitler's ship, and it was outstanding.

EUGEN BENTELE
Speaking in German
If you want to travel in a beautiful, elegant and thoroughly pleasurable way you're first choice has to be a Zeppelin. When it comes to elegance, the most luxurious cruise liner is no match for the Zeppelin.

COMM
Other airships companies were less successful. In 1925 the British R33 was ripped from her moorings by gale force winds, and four years earlier, the R38 broke apart during a test flight-killing 44.

Accidents like these had already marked the beginning of the end for the British and American airship initiatives.

During one notorious incident in 1932, 2 members of the ground crew fell to their deaths when the USS Akron broke free during a landing.

JOHN PROVAN
The Germans were far more advanced than then British or the Americans in the sense of airship technology. The British unfortunately had somewhat of a haphazard arrangement of simply copying captured German airships during the First World War so that they really didn't have that tradition and that fundamental technology that you needed to build airships.

COMM
The Hindenburg's value as a propaganda tool was quickly recognised by the Nazis, but Hugo Eckener, the head of the Zeppelin Company, was well known for his hostility towards the Third Reich.

JOHN PROVAN
Eckener was very open and blunt in his distaste for the Nazi party. In fact it's probably a wonder he survived WW 2. One example being it was anticipated by the Nazi Party that the Hindenburg would be called the Adolf Hitler and Eckener did not like the idea very much and had of course then the lettering Hindenburg put on very quickly to eliminate any temptation, if you will.

COMM
But despite his efforts, Eckener was powerless to prevent the Nazis from using his ship.

Hitler remorselessly exploited the Hindenburg's image, commandeering her for leaflet dropping during his political campaigns.

JOHN PROVAN
The Nazi party ordered that the swastika be put on the tails of the airships, and with that then the how shall we say the party leaders used the airships as a propaganda tool, and you have this airship flying overhead and Hitler standing there with his chest out, you know - This is Nazi Germany.

COMM
The Nazi's confidence in the Hindenburg was more than justified. By the 1930s, the Zeppelin Company had accumulated a huge reservoir of expertise in both building and flying airships.

What distinguished the Hindenburg was the sophistication of her construction. Like all the Zeppelins, she was a rigid airship, built from an intricate lightweight aluminum inner cage that contained both the lifting gas hydrogen, and the passenger and crew areas.

COMM
The living areas were located at the bottom, but the core of the airship was formed by the axial walkway.

Surrounded by the sealed gas cells, the walkway ran the entire length of the ship.

Underneath the cells, along the bottom, was the main walkway. Almost 800 feet long, it was used by the crew as the principal route for getting from end of the ship to the other.

The walkway linked the control and steering car hanging beneath the front of the Zeppelin, to the passenger decks located in the middle.

COMM
The passenger decks were built within the body of the ship, at the bottom of the hull, and held the lounge where passengers gathered to gaze out the large viewing windows. These decks also contained the dining room and cabins.

COMM
Further back, above the freight and mechanical areas, towered the sixteen enormous gas cells containing 7 million cubic feet of hydrogen.

Hydrogen is highly flammable when mixed with air, but with its years of experience, the Zeppelin Company was confident the gas could be controlled. Elaborate safety features were designed to minimize the risk of fire and to prevent any accidental hydrogen leaks.

JOHN PROVAN
The Germans felt perfectly safe with their hydrogen. It was definitely considered safe by all the crew members because they had never had any reason to fear it. It was an evil that was in Pandora's Box that they knew how to control. In the smoking room for example the room was always under pressure to keep air going out of the room instead of hydrogen in any way, shape or form coming into the room. There were any number of safety precautions which they had taken.

COMM
The ship's captain controlled the hydrogen through a sophisticated system of wires and pulleys attached to valves on the sides of the cells.

These allowed him to release hydrogen in order to decrease the ship's buoyancy. The vented gas would automatically flow upwards through a sealed airshaft to a series of vents on the ship's upper cover.

To minimize the risk of a hydrogen fire, the system also ensured that any leaking hydrogen would make its way up to the vents and then safely dissipate into the atmosphere.

ALFRED GROZINGER
COOK
(speaking in German)
Translation: Everybody was fully aware at the time that if there were to be a fire on board the air ship, that this would mean more or less the end for all of us.

COMM
By 1937, the Hindenburg had already logged 10 successful round trips from Germany to her American destination, the naval air station at Lakehurst New Jersey.

Docking had become all but routine,
although large landing crews were required to manhandle the unwieldy ship to her resting place on the mooring mast.

In the air she was as graceful as a cloud, but once she dropped closer to earth, she was somewhat more cumbersome.

For her first flight of the 1937 season, she was carrying ninety-seven people-thirty-six passengers and sixty-one crew. Delayed by persistent headwinds during the transatlantic crossing, she was hours behind schedule when she arrived over Lakehurst.

VERNA THOMAS
That particular day, the 6th of May, in 1937, it was raining very bad rain, electrical storm, and the ship was due in, and word got out on the radio - we didn't have television -the radio stated that it had to delay it's flight into Lakehurst until it got cleared up.

JOHN IANNACCONE
I was part of the military ground crew, and if it was delayed, I mean we would have to wait until it got here, and it was twelve hours late.

VERNA THOMAS
When the word came through that everything was clear and that they were going to land the ship, my husband asked me if we would got to see it, to see the Hindenburg, and I said yes, so my son was not quite four and we went in.

EUGEN BENTELE
(speaking in German)
Translation: I was keeping watch in the forward engine car on the side of the airship when we flew in over the field to check the ground crew had everything ready for the landing.

RADIO COMMENTATOR
How do you do everyone? We are greeting you now from the Naval Airbase at Lakehurst New Jersey from which point we are going to bring you the description of the landing of the mammoth airship Hindenburg. But here it comes ladies and gentlemen and what a great sight it is. It is a marvelous sight . . . it is pointing down directly towards us . . .

VERNA THOMAS
It was fabulous, it was the most beautiful sight you would ever want to see, and the people and everything were so happy coming in that particular day.
I had seen it come in every time but not as close as I was this day.

RADIO COMMENTATOR
It is practically standing still . . . it has been taken ahold of down on the field by a number of men.

ALFRED GROZINGER
(speaking in German)
Translation: I could see the landing ropes being fastened on a winch below


when suddenly there was a massive jolt through the ship and I thought oh God, something's happened.

EUGEN BENTELE
(speaking in German)
Translation: My first thought was that the landing crew had pulled too hard and something had broken but that wasn't it. When I looked out I saw flames shooting forward from the rear of the Hindenburg towards my engine car.

RADIO COMMENTATOR
It bursts into flames, get this Scotty, get this Scotty, Ed its crashing, its crashing terrible, get out of the way please...

ALFRED GROZINGER
(speaking in German)
Translation: Everything went so quickly, the way the ship seemed to rise in the air. I planned to hold on to the frame until the ship hit the ground and then jump. All I remember is feeling a shock in my hands - and then I fell.

EUGEN BENTELE
(speaking in German)
Translation: I remember my heavy engine car crashing to the ground and then I passed out for perhaps a few seconds.

RADIO COMMENTATOR
...get the terrific...the smoke and the flames now...crashing to the ground...all the humanity and all the passengers screaming around me. I can't talk ladies and gentlemen...I'm sorry...I'm going to step inside for I cannot see it.

VERNA THOMAS
Everybody, everybody kept running away and then afterwards running back towards it to see what they could do, trying to help everybody out and pulling this and pulling that, and then the sirens were blowing and the ambulances.

JOHN IANNACCONE
The fire went so fast through there that by the time it go to the nose it came out of there like a blowtorch.

VERNA THOMAS
The smell, the smell of the hydrogen and the blood, the rubber, was terrible. And of course there must have been human flesh in there because you could smell it and it's like, I've always said, you never forget it, you would never forget the smell.

COMM
It took less than one minute for the fire to completely consume the Hindenburg. The disaster claimed the lives of 36 people-thirteen passengers and twenty-two crew aboard the ship, and one civilian crew member on the ground.

ALFRED GROZINGER
(speaking in German)
Translation: I thought my end had come but suddenly there was the ground. Luckily it was sandy and soft and I had more or less fallen on my feet. Immediately I picked myself up and ran away.

JOHN IANNACCONE
As we got closer to the ship there was a man still in there and he walked out of the ship after the nose of the ship was on the ground, he didn't have a stitch of clothes on him. And everything was burned . . . and the only thing he had on him was his shoes. Everything, skin, hair, everything was burnt. And he didn't, he died right there.

VERNA THOMAS
It was like a fire of hell. Everybody. Oh God, oh God, that's all they were keeping saying, because you couldn't help it, that's...And there's nothing you could do, there was nothing you could do all I could do was just look and cry.


COMM
A fleet of ambulances ferried the injured to nearby hospitals, while firefighters worked through the night to douse the flames. The shocked township of Lakehurst, New Jersey struggled to come to terms with the scale of the tragedy.


MOVIETONE FILM
A twisted, tangled mass of seared girders and bits of blackened fabric are all that remains of the proud luxury airliner Hindenburg that lies at the Lakehurst Naval Station. The death list is now 35 with ten including Captain Kruz still on the critical list.


COMM
In Manhattan, an extraordinary memorial service was held for the Hindenburg's German victims. They were paid full Nazi honors as they lay in state, ready for their final voyage home to Germany.

Quickly, attention turned to what could have gone wrong:


JOHN PROVAN
There were numerous theories as to what caused the crash . . . turkey farmer taking a pot shot, there was every conceivable theory that you could imagine. The problem being proof what really happened. It was simply very difficult to discern when the airship is lost basically.


COMM
At Lakehurst, investigators began pouring over the wreckage to look for clues.

One probe was led by American officials, while Dr Eckener and his senior colleagues from the Zeppelin Company supervised their own parallel inquiry.

In the face of intense media speculation regarding the cause of the crash, Dr Eckener remained tight-lipped.

ECKENER
As long as the investigation is pending, it is impossible for me to give you any statement or any ideas regarding the causes of the disaster.

COMM
The very first suspicion was of sabotage. By 1937, the world was waking up to the evils of the Nazi regime, so the motivation for destroying such a powerful Nazi symbol was obvious.

JOHN PROVAN
The Hindenburg was a vulnerable target for an act of sabotage. It would not have taken a very big explosive device to destroy that airship.

COMM
The FBI was called in to investigate, and immediately began background checks on the passengers and crew. Everyone had been subjected to a thorough search prior to embarking, so the investigators were looking for someone determined enough to smuggle an explosive on board.

COMM
Attention quickly focused on a passenger named Joseph Spah, who had survived the crash.

Spah was an odd character. A German acrobat, he lived in America, which put him under suspicion as a possible spy. He was also thought to be supple and strong enough to climb into the ship's structure to plant a device.

Spah was also found to have had with him a camera and flash that could have easily been rigged to start a blaze.

But the theory did not pan out. No hard evidence against Spah could be found, and the FBI eventually reported that the sabotage theory was a red herring.

With sabotage ruled out, the investigators turned to the only other explanation they could think of-mechanical failure. In the days before black boxes and flight recorders, they had to glean all their clues from eyewitnesses.

Despite 55 prior safe flights, the search was on for a design defect in the Hindenburg that could have caused the disaster.


The obvious weak point in the design was the use of the highly flammable lifting gas, hydrogen, and the investigation shifted to ways leaking hydrogen could have triggered the fire.

COMM
The Hindenburg's arrival at Lakehurst that May 6th had already been delayed due to bad weather, and when she came in to land there were still storms in the area.

As the ship flew in for her final approach just after seven o'clock,
hydrogen was vented from the control car to bring her back to earth.

She then began her final, tight turn, angling herself into the direction of the wind in front of the mooring mast.

The final maneuver was the release of the landing lines.

Only minutes later, the spectators and ground crew saw the first signs of fire, at the top of the ship just in front of the fin.


COMM
Based on the testimonies of the 97 eyewitnesses, the investigators were confident they knew where the fire had started - all they needed now was to explain why. Automatically, suspicion focused on the highly flammable hydrogen gas:


ADDISON BAIN
The investigators at the time unequivocally just assumed that since hydrogen was used as a buoyant gas that somehow it got loose because it was flammable. Okay where's the hydrogen coming from, it's gotta come from a gas cell. Well was it a natural thing, was a gas valve stuck - they ruled that out. So next what appeared to be logical was that a gas cell was breached by some technique, in other words it was torn or something like that.
COMM
But the hydrogen breach hypothesis was little more than speculation.
Using the investigative tools available at the time, the inquiry found no evidence to back the idea that a cell had leaked.

Nevertheless, since no other explanation was available, the investigators put forth what seemed like an entirely logical theory-with hydrogen at its center.


COMM
They concluded that hydrogen leaked, combined with air to form a lethal mix, and was then ignited by a spark from a buildup of static electricity.


JOHN PROVAN

Hydrogen was the weak point in the concept if you will: it was flammable very flammable when mixed with air - it ignited, simple as that.


COMM
The 63 page Department of Commerce accident report concluded,

"The cause of the accident was the ignition of a mixture of free hydrogen and air. Based upon the evidence, a leak (...) caused a combustible mixture of hydrogen and air to form in the upper stern part of the ship in considerable quantity"

"The first appearance of an open flame was on the top of the ship and a relatively short distance forward of the upper vertical fin."

COMM
Today, vast Hangar One at Lakehurst lies empty. Because of the official verdict blaming hydrogen, the great Zeppelin passenger airships never flew again, and hydrogen was permanently tarnished as an unsafe, explosive gas.


VERNA THOMAS
After the Hindenburg I would say there was a decline in all airships at Lakehurst, and no matter how we fought we just couldn't get them back in. The decline was very bad after the Hindenburg.


HEP WALKER
Nobody would operate with hydrogen, that's the thing, and Dr Eckener forbid any more flights with hydrogen. Hydrogen was a no-no.


COMM
As the rusty doors on the hangar at Lakehurst roll grudgingly back sixty years later, the Hindenburg dossier is once again being opened.

For the first time since the accident, the unchallenged assumptions about the role of hydrogen are being questioned, and subjected to modern forensic techniques.


ADDISON BAIN
The course of the investigation just assumed free hydrogen, and then they backed up to try to find an excuse for the free hydrogen. That's pretty bad science.

5...4...3...2...1...0 and liftoff of the Space Shuttle Endeavor...to develop the practical and the beneficial aspects of space...

COMM
The Kennedy Space Center in Florida is the hub of NASA's launch operations, and it is here that retired engineer Addison Baine has spent his career working with hydrogen-used in rocket fuel because of its extreme flammability.

It was Bain's NASA experience with hydrogen that first sparked his interest in the Hindenburg mystery.


ADDISON BAIN
I was on a one year assignment in Washington DC at the NASA headquarters which is right across the street from the National Air and Space Museum, so I used to go in there quite often, particularly for having lunch. But there's a model of the Hindenburg in there , a 25 foot long model used in the 1975 universal studios movie. There's a plaque on the wall, and it said essentially: the hydrogen exploded. Well that bothered me a little bit.

COMM
As a specialist who passionately believed in hydrogen's potential as a clean fuel of the future, Bain wondered whether the gas had unfairly taken the blame for the Hindenburg catastrophe.

He began to investigate, and has now spent nine years methodically re-examining the official account of what happened at Lakehurst that day.


ADDISON BAIN
The investigators at the time unequivocally just assumed that since hydrogen was used as a buoyant gas then somehow it got loose because it was flammable. As you read through the reports and you look at how it was built up there was no physical evidence building to the conclusion, and there was no testing done to also support that evidence. So that made the story more suspicious.


COMM
Bain's first step was to test the feasibility of some of the original inquiry's assumptions.

In the workshop of hydrogen specialist Frank Lynch, he built a scale model of the ship's tail section, where the report had concluded the fire began. The model allowed him to probe the hydrogen theory by observing precisely what would happen if a hydrogen cell had ripped and developed a leak.


ADDISON BAIN
What I've done Frank on the model is run a piece of tubing up here to come out on the gas cell number four here to represent a leak in cell four. Estimating a gash of maybe, about almost a meter wide...At 80 to 1 that's a huge hole...And then, I would suspect then, the hydrogen gas will come on up and go out the vent here, or aout the vent in the tail there...






COMM
The flow of hydrogen through the model simulates the flow rate from a good-sized leak in one of the huge gas cells on the Hindenburg. A hydrogen detector is then used to see which way the gas flows.

ADDISON BAIN
Lets try the forward vent here...Ooh, its coming out of there already. OK, we've got stuff coming out of there...Lets try back here, at the vent back here, to see if we've got anything come...

COMM
The model suggested that any leaking hydrogen would quickly have flowed upwards, towards the vents, exactly as the designers had intended. And near the vents is exactly where the eyewitnesses had seen the fire begin. The logic behind the hydrogen theory appeared to be impeccable.

ADDISON BAIN
What the model shows is if you had a hydrogen leak in a gas cell, where is the hydrogen going to go, and basically out up through the vent stack and that's where you would suspect the logical fire to start, but it didn't.


COMM
Bain had made a startling discovery. Reviewing the eyewitness statements, he realized that the official report contained a glaring omission. The investigators had completely disregarded the testimonies of 2 key observers who saw something others had not. Their perspective was crucial, because they had a view of this, the starboard side of the ship.


ADDISON BAIN
Most of the witnesses were on this side up on the port side, up near the nose of the airship, then there were witnesses on the port side some distance away. There were very few witnesses to observe anything on the starboard side. In testimony there are two people to discuss events occurring here first before the fire spread.


ACTOR #3
(ASTONS:)
"The first burning out of the fire, was on the starboard side above and, up."
Helmut Lau

ACTOR #4
"I saw a small flame immediately in the back of the top fin. In the back of the fin, in the back of the whole surface and the rudders."
Elizabeth Tobin


T.V. COMMENTATOR
A roar and a burst of flames, near the big tail fins turns the ship into a flaming inferno...

COMM
The hydrogen theory only made sense if the fire had started at the vent. Bain's discovery that it had begun elsewhere was the first indication that the initial conclusion was flawed.

But to his expert eye, there was an even more glaring contradiction.

ADDISON BAIN
Well I've played around with hydrogen and created fires myself with hydrogen, some by accident and some on purpose, but in the case of the Hindenburg the action there was simply, just, was not familiar with my experience with handling hydrogen. Something else was taking place there.


COMM
Though hydrogen is chemically unstable and highly flammable, hydrogen fires are very difficult to see with the naked eye, radiating a cold, blue flame.

Because it is lighter than air, hydrogen also tends to burn upwards very quickly. Yet the eyewitnesses were remarkably consistent when describing the colors of the fire:


VERNA THOMAS
It was like a fire of hell; it was so intense and so red, very red with the orange flames in it.


JOHN IANNACCONE
I could see the whole airship from nose to tail where I was standing and I saw that big red orange glow and all of a sudden the fire started firing and it came out through the cover.


COMM
Those descriptions of the color of the fire were important clues, but Bain had only black and white photos to work with. By carefully sifting through all the descriptions, he created a color image of what witnesses said the fire actually looked like.


ADDISON BAIN
This is a consensus, a cumulation of eyewitness accounts as they described it, and I sort of just built a spectrum of what they talked about and then recolorised this on the computer to show that. Typically a yellow orange reddish type flame was observed, and of course as we all know hydrogen is basically invisible in daylight. Well that's fine I realized at some point in time that hydrogen is part of the fire there's no question about that, but it's being masked by this intense flame.


COMM
The colorized photograph showed that the cause of the Hindenburg accident was far more complex than the straight hydrogen fire assumed by the official report.

And the photograph had further significance: It showed that the airship remained buoyant many seconds after the fire began.


ADDISON BAIN

The airship's still in trim, which means that a significant amount of hydrogen is in the cells back here. If there'd been a significant loss of hydrogen in the stern area it should have started descending immediately.


COMM
The fact that the Hindenburg didn't immediately plummet when the fire started, was further evidence of a flaw in the hydrogen theory.

And Baine noticed another inconsistency when reviewing film footage.


T.V. COMMENTATOR
Thirty Six persons died in the flaming wreckage of the proud airship. To this day the exact cause of the explosion remains a mystery . . .

ADDISON BAIN

The fire was so rapid and it actually engulfed the airship, and that's not characteristic of a straight hydrogen fire that would burn you know something like a propane burner, burning upwards basically. Now there was a slight wind, you could say it would angle off to one side, but nevertheless the whole action of the fire was almost like being in a forest fire where you have the fuel all around you. Okay sure the airship was burning, was it being fuelled by the hydrogen or was it being fuelled by something else?


COMM
To Baine, the speed of the fire and its distinctive orange color were clues that the Hindenburg contained something flammable besides hydrogen.

Around the aluminum frame, the airship was built of wood, cotton fiber and other combustible materials that could have given the fire its orange appearance.
But what most intrigued Bain was the incredible speed with which the ship's outer cover had burned.

He calculated that the flame front along the outside had advanced as fast as 49 feet per second.



The fire went so fast through there it came out like a blowtorch. Within five seconds the whole top was gone. It was so fast. It only took 34 seconds to burn - I mean it just blew right out of there.


COMM
The Hindenburg's outer cover was a key feature of Zeppelin's technology.

Designed to give the ship an aerodynamic profile, it also had to be waterproof, and heat reflective, to prevent the hydrogen from expanding.

Zeppelin's engineers achieved this result by painting the cover with a doping compound containing a cocktail of chemicals.

Where the chemicals to blame for the fire?



COMM
Searching through the archives, Bain found hints that a new doping compound had been used on the Hindenburg, but he struggled to find datails of the change.


ADDISON BAIN
It was a mystery in itself. I had gone through five different archives, thousands of pages of information. I accumulated libraries from other people, experts on airships, collectors, purchased many many books on airships and read through them and frankly could not find what specifically what was used to coat the Hindenburg.


COMM
Despite the lack of information about the doping compound, Bain felt sure there was a fatal flaw in the official explanation blaming hydrogen for the crash.

He believed the truth lay in the airship's outer cover, but he needed hard evidence to prove it.


ADDISON BAIN
The breakthrough came when I was attending a hydrogen conference in Coco Beach and I saw a gentleman walking around with an airship book under his arm and I walked over to him and said may I see that airship book and he introduced himself as Richard Van Treuren and said he was looking for Addision Bain to talk about hydrogen and I said, well, I'm here.


COMM
Richard Van Treuren is a dirigible enthusiast with a multitude of contacts in the airship community. He was fascinated to learn about Bain's new theory.


RICHARD VAN TREUREN
Well up until the point of our meeting Dr Bain had not been able to find specific information about the Zeppelin's outer covering. Nothing has been published about it. So I was able to introduce him to a Mr. Hepburn Walker a WW2 airshipman who had saved actual samples of the Hindenburg fabric from where she fell.


HEP WALKER
Well I try to get samples of any airship, especially rigid airships. I got samples of the girders for the Los Angeles, the ZMC2 metal clad airship, The Hindenburg of course is the most famous airship in history, and I figured I'd want a few samples of the girder work and the fabric work I went out there and scuffed my foot and dug up pieces of fabric and so on


COMM
Remarkably, fragments of the outer cover had survived the blaze and were strewn across the landing site at Lakehurst.


ADDISON BAIN
Oh when I found that there were some fabric samples, remnants of the Hindenburg, I was ecstatic, I said: I know how to go about finding out what's in those materials.


COMM
The existence of genuine Hindenburg samples proved to be a key breakthrough: It meant that for the first time, Bain could study the chemical makeup of the outer cover, to see why it had burned so quickly.

Examining the fabric under an electron microscope, and then using infrared spectroscopy, he was able to determine the precise mix of chemicals used in the doping compound.

SCIENTISTS
...this is the band we were looking for...
...what was that showing there.

COMM
He found that the doping mixture contained iron oxide and powdered aluminum.


ADDISON BAIN
Being associated with space shuttle activity I knew that powdered aluminum was the fuel used on the boosters, and I thought: Boy what a bad combination.


COMM
The external boosters on the space shuttle are powered by a solid rocket propellant containing both aluminium powder and iron oxide!

Bain's experiments had confirmed that those same chemicals were present in even greater quantities in the doping compound used to protect the Hindenburg's outer cover.

The Hindenburg had been painted in the ingredients for rocket fuel!

To prove that the flammable chemical cocktail had allowed the cover to burn so quickly, Bain still had to fit one final piece into the puzzle: He needed to determine how the fire had started.


COMM
He turned to the Air Force Research Laboratories in Ohio-the United States' leading center for the study of the physical forces that affect aircraft.

One key team at the center specializes in the dangers associated with sparks caused by electrostatic charges in the atmosphere.



VOICE OVER
OK, we've got 45 torr, go ahead and bring the voltage up...

LARRY WALKO
As an aircraft flies through the atmosphere it actually can build up a static charge on the surface of the aircraft from what we call P static or precipitation static and that's just from flowing through the atmosphere.


COMM
Precipitation static can build up on any aircraft-including an airship.

More importantly, the Hindenburg's landing at Lakehurst that fateful day had been delayed by bad weather, so the pilot was trying to squeeze the landing in between two large electrical storm fronts.


LARRY WALKO
There were thunderstorms in the vicinity which meant that the atmosphere probably was increasingly charged. This could be a factor in putting a substantial charge on the surface of the Hindenburg, more so than on a regular day


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Yet this had all been anticipated by Zeppelin's engineers. The internal frame of the airship was designed to be electrically bonded, so that any charge it carried would flow harmlessly to earth without a spark, the moment the landing lines touched the ground.


LARRY WALKO
You have to have electrically, a good conductive path so if you get charging on an aircraft or if an aircraft gets struck by lightning, that the high currents or the high voltage build up will have a good electrical, low resistive path to flow on or off the aircraft,


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While investigating the ship's design, Bain discovered that the Hindenburg would not have been properly bonded.

The outer cover was made up of individual panels of doped cloth attached to the airship's main frame by light cords. These cords were poor conductors, and would have made it difficult for any charge carried on the panels to run to earth.

Because of the high humidity and rain that day, some cords would have been more conductive than others, better bonding their panels to the rest of the airship.


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Any electricity on the bonded panels would safely have run off the ship when the landing lines were released.

But some panels would have remained electrically isolated, retaining a huge voltage that would seek the easiest possible route to earth.

Eventually the voltage difference between those panels and the earthed frame would be so great that a spark could leap across the gap, allowing the electricity to discharge.

Clearly visible under an electron microscope, the aluminum particles in the doping compound would be a good conductor for that discharging electricity.


ADDISON BAIN

The electrostatic charge has an affinity or an attraction to powdered aluminium, so once that reaction starts then the aluminium gets extremely hot of course and it's in a very flammable environment, namely the cloth and the dope that's used on the cover. What's important there is.The combination of those ingredients can be almost explosive.


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That electrical current discharging through the cover would also generate heat, enough to set the highly flammable aluminum alight, triggering the ensuing blaze.


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The Zeppelin engineers would not have realized they were playing with fire. They picked the aluminum powder because of its reflective properties, but at that time, would not have known about its extreme flamability.

With his last question answered, Bain is now ready to present his theory about what really happened to the Hindenburg.


The landing that day had been postponed by bad weather.

When the Hindenburg finally arrived at Lakehurst shortly after seven o'clock, the rain had just stopped and there were still thunderstorms in the area, meaning that the atmosphere was more charged than usual.

The captain prepared to make his final turn into the landing mast, gently slowing the airship down while venting hydrogen from the gas cells.

As the ship approached the mast and the landing lines were dropped, most of the electricity on the ship discharged to earth - but crucially some of the outer cover panels were insulated from the main frame, and retained their electric charge-the trigger for the fatal sequence of events that followed.

ADDISON BAIN
I believe the sequence of events first started back here near cell one and two where there was an electrostatic. Discharge occurring across the fabric and through the frame. That essentially ignited the highly flammable outer covering material which then burnt quite rapidly. That intense heat from that fire then expanded the gas back here in cell one to a point where is actually exploded back here and caused a forward jerk in the airship. The hydrogen then from that cell obviously came out and started burning above the airship but in the meantime very rapidly all this was occurring, the fire moved very rapidly forward up over cell four which was observed on this side then rapidly came across and then forward.


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It was only at that point that the film cameras began rolling.

Newly colorized footage shows the true appearance of the fire.

As the flame front advanced down the ship, bursting the gas cells below, hydrogen began to fuel the blaze, its blue color masked by the bright orange of the other burning materials.

Bain is confident his is the true explanation for the Hindenburg disaster. But his theory is controversial, upsetting sixty years of perceived wisdom about the role of hydrogen:


JOHN IANNACCONE
ADDISON BAIN
You can't tell me that the hydrogen wasn't burning in that thing . . .
Once the rear cells went the hydrogen started contributing to the fire there is no doubt about that. . .
But the glow was in the there before the fire broke through the fabric. I saw the big red glow from that cell . . .
Yeah, from your position that is what you would have seen . . .
Yeah, I saw that big red glow . . .
Sure you did, but that is not hydrogen going John. . .
Well, something was burning . . .
You bet it is . . .
But it wasn't the fabric and I could see from where I was standing the whole top of it . . .
And what you saw was right. But what you didn't see was a few seconds ahead of that . . .


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The scepticism would continue as long as Bain's account remained just a theory.

To prove it conclusively, he decided to conduct one more, vital experiment. He would need to sacrifice a valuable original piece of the Hindenburg's outer cover and subject it to the kind of extreme voltages seen that night.

Unlike ordinary fabric, would the Hindenburg's doped cover catch fire as he predicted?


ADDISON BAIN
This came from the top part of the Airship. I know that because of the iron oxide coating and you can see where it was burnt around the edges and these two rip marks here probably came off the cover and fell to the ground and probably self extinguished with the water on the wet ground that day. Lets cut a small sample off here and put it in the machine and then we are going to turn in on and see if it ignites. Recall now that this sample is over 60 years old. The collectors clubs of the world are going to murder me for doing this. Destroying an artifact.


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Combustion is virtually instantaeneous.

The Hindenburg disaster would have happened whether or not the ship was filled with hydrogen. As with the Titanic and Space Shuttle Challenger disasters, a vital but overlooked technological flaw had proved fatal.

Although sixty years old, the sample still shows all the signs of high flammability.



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But there was one final twist to come. Deep in the archives of the Zeppelin Museum in Germany, the Hindenburg had one final secret to reveal.



ADDISON BAIN
One of the crowning experiences in my investigation was the opportunity to go to Germany and visit the Zeppelin Museum and go through their archives. And frankly by accident I came across some very interesting information that's been there for a long time


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Within the museum's archives lay the unpublished records from the German inquiry into the disaster.
Scientists working for the Zeppelin company had secretly conducted their own experiments on the Hindenburg's outer cover. The conclusion they had reached was remarkable: with the right conditions, the cover would catch fire, whether or not the airship was filled with a flammable gas like hydrogen.
Dr. Max Dieckmann was a member of that scientific team.


EDITH DIECKMAN
(speaking in German)
Translation: When my husband got back from Lakehurst he went straight to his lab to carry out test on models, firstly on the cover of the earlier Graf Zeppelin, then with the Hindenburg. Both were made wet as they would have been on the night, and then they were grounded.
Nothing happened to the Graf Zeppelin cover, but the Hindenburg cover immediately caught fire.

ADDISON BAIN
It's ironic that the tests that were done two months afterwards are the same tests that I have run sixty years later. From what I can tell that specific finding was never made public and I've learned that it is probably for insurance reasons, politics at the time - obviously the Third Reich didn't want to be embarassed by some bad engineering. I think it was nothing but a cover up.


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Zeppelin quietly made a number of design alterations to the Hindenburg's successor, the LZ130. Bronze was added to the doping compound to make it less flammable, and the electrical bonding was improved to reduce the risk of sparks.

The changes came too late.
At the outbreak of war, the Nazis destroyed all the remaining Zeppelins. With the advent of fast reliable airplanes, the fate of the airship was sealed.

The Zeppelin Company never revealed the truth about the disaster. The view of hydrogen as a dangerous and explosive gas became the accepted one, much to the frustration of specialists like Addison Bain, who see it as the fuel of the future.


ADDISON BAIN
Even when I was involved in writing hydrogen safety manuals for NASA, invariably the topic of the Hindenburg came up and it's left a very bad stigma, the public perception is that hydrogen is very dangerous - because of the incident. But I think now that the real story has come out, it may be able to mitigate and dispel that myth.



RICHARD VAN TREUREN
Once we realize the Hindenburg fire was not a hydrogen fire we can once again look at buoyant flight, and its associated efficiency, its environmental friendliness and the other traditional advantages that we've missed for these past 60 years, we can bring airships back to the mainstay and have them fill the role they are good at.


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While it is unlikely that airships will once again rule the skies, Bain's work seems to have finally laid to rest the mystery of what happened to the Hindenburg.