a bridge 4.5km that way to this bridge Pont d'Argenteuil.

As the plane flew along the River Seine lined with spectators, one pilot put his hands in the air,

while the other walked out onto the wing, and yet the plane continued to fly level.

It was the first public demonstration of autopilot, an innovation that changed the aviation world forever.

In the plane that day were these two men.

French mechanic Emil Cachin and American aviation pioneer Lawrence Sperry.

Sperry was the son of the famous inventor and entrepreneur Elmer A. Sperry,

often referred to as the “father of modern navigation technology.”

Elmer Sperry formed eight companies over his lifetime,

including an electric, mining machine and fuse wire company.

But arguably Sperry's greatest creations were his versions of the gyroscope,

turning a children's toy into useable technology to help tackle real-world problems.

There was a lot of demand within the maritime industry for an instrument

that could replace the unreliable magnetic compass within steel ships.

The German inventor Hermann Anschutz-Kaempfe patented the first workable gyro compass in 1908,

and Sperry developed his own shortly after.

It was the first creation from what was initially called the Sperry Gyroscope Company,

his business that grew to become a global technological powerhouse.

Over this period, Sperry also developed a gyro pilot system for ship's steering and

and built the first full gun battery fire control system.

After reportedly suffering from sea sickness on an earlier Atlantic voyage, he also designed

a gyroscope that stabilized ships by reducing the roll caused by waves, particularly during rough conditions.

However, it was in aviation that Elmer's gyro stabilizer reached new heights.

"A great many great men have contributed to aviation purely as specialists, Sperry one of the greatest."

In 1914, the world got to see a plane on autopilot for the first time

when Laurence showcased his smaller and lighter version of the gyro stabilizer,

the original gyroscopic autopilot.

While this controlled the surfaces of the aircraft to maintain straight and level flight,

the basic principles were the same.

Think of a gyroscope as a spinning top.

When stationary, it falls over, but when spun at speed, it's able to retain its position.

This is known as the conservation of angular momentum.

Now imagine the spinning top as a wheel or disc,

attached in some cases to many other moving parts such as gimbals.

The angular momentum of the spinning rotor causes it to maintain its position

even when the gimbal assembly is tilted.

The idea of the gyroscopic autopilot is that the three axes of an aircraft, yaw, pitch and roll

could be harnessed to the stability of a spinning gyroscope

which could maintain an airplane's original orientation.

This was done by linking the control surfaces of the aircraft with three gyroscopes

that were designed to maintain a zero setting unless the pilot took over the controls.

This allowed flight corrections to be introduced based on the angle of deviation

between the flight direction and the original gyroscopic settings.

To see these gyroscopes in person I've come to Farnborough, a town in the U.K.

It's a historic aeronautical science site responsible for the development of equipment

such as the first airborne cameras and high-altitude space suits.

It also conducted the first carbon fibre experiments.

Hi Graham, how's it going?

Morning, welcome to FAST.

Graham Rood is a retired aviation scientist and engineer who collects and archives aviation gyroscopes.

We've got quite a large collection of Gyros over the years.

The very early ones were powered by pressured air through there

and that spun up the gyro like that at high speed.

Once you've set the gyro up in a particular direction, every time there's a movement

you can correct it because you can sense the movement with other sensors

and the gyro is basically the controlling system.

I mean they were fundamental to all flying. Clever man, clever man, good use of technology.

Any of these gyros built by the Sperry family?

We don't have any in here but we do have some down in the reserve collection.

While gyroscopes were Elmer's and Laurence's most successful venture

they continued to create a wide variety of equipment and machinery.

In total, they held more than 400 patents for new inventions across several different industries.

This is the one where we have some of the Sperry work in.

We store it all here, everything is numbered.

Sperry-made gyros.

Wow.

And you can see how beautifully made it is.

This was probably 60s or 70s, something like that.

You see Sperry Gyroscope, these were some of the gyros of the time.

Sperry Gyroscope Company.

Of course, a lot of people made gyroscopes but Sperry was right at the beginning.

So this is artificial horizon.

That's where your airplane is, so that's the wings and you can see the horizon moves around.

And they always have this lovely little, "Do not jar handle my eggs."

That's great.

Sadly, Laurence Sperry died in a plane accident in the English Channel in 1923,

and his father Elmer passed away seven years later.

Their legacy, however, lives on in today's aviation industry.

Well, I think for engineers and certainly people who can look back and understand history,

they were real giants of aviation and that's how they should be remembered.

After their deaths, the Sperry Gyroscope Company became a subsidiary of the new Sperry Corporation.

The new company immediately set to work on the development of two flight instruments.

These were the Directional Gyro, now known as the Heading Indicator,

which tells the pilot the direction the aircraft is heading

and the Gyro Horizon, now known as the Artificial Horizon,

which informs the pilot of the aircraft's position relative to the earth's horizon.

They were tested in 1929 in what was the first recorded flight in history using only instruments.

Jimmy Doolittle, in association with the Sperry company, tackled the problem.

I made the first blind flight but out of that came two instruments, the artificial horizon and directional gyro

that are today standard equipment on every commercial airplane and every combat military airplane.

How do you do, Tom?

Good, nice to meet you.

And you, and you.

Paul Heaver is a retired British Airways pilot.

His career spanned 44 years and yet gyroscopic instruments

were as important on his last flight as they were on his first.

It is an essential part of the information that you receive as a pilot

on the attitude and the manner in which the airplane is flying.

When one starts training in the first place you fly visual flight rules where you're

looking out the window most of the time etc, and then you progress to learning how to fly

on instruments and so the information that you get provided by gyroscopes, artificial horizons,

turn and slips, is critically important.

And even today, certainly on the 747-400 there will be stand by instruments.

How important was autopilot during your career?

I can remember on one occasion, I went to put the autopilot in and we couldn't get the autopilot in.

And so we had to hand fly this airplane from Perth to Singapore

which was about five and half hours but it was just tedious, it was just boring.

So, with an autopilot that's all taken care of and you can just monitor what is actually going on.

You don't have to look far to see the impact the Sperrys had on today's aviation and technology industries.

The Sperry Corporation has contributed to the development of some of the world's biggest companies.

After a series of corporate mergers, Sperry Corporation eventually became a part of

the American global IT company, Unisys.

Following the merger, some of its former divisions were sold off and have gone on to form parts of

Honeywell, Lockheed Martin, United Technologies and finally Northrop Gruman.

Last year each company had revenues of more than $30 billion.

And the Sperry name continues to live on in the Northrop Grumman-owned company Sperry Marine.

It's a global supplier of navigation, communication and automation systems for the marine industry.

From shipping to computers, the Sperry Corporation's influence can be felt across multiple industries.

But it's in aviation, through the original Sperry Gyroscope Company,

that Elmer and his son Laurence left a legacy of invention and engineering

that continues to be relevant and effective even in today's digital economy.

Hi guys, thanks very much for watching our video.

If you want to see more of our content then check out these videos.

And we'd love to hear your thoughts on Sperry and gyroscopes,

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