I looked at this machine sitting there and I thought, “Wow.”

It led the way in aviation technology but its program lasted less than 30 years.

SST or supersonic transport hasn't been seen since in commercial aviation,

but it may be about to make a comeback.

Flying faster than the speed of sound may feel like a relatively new phenomenon,

but the first Concorde took to the skies the same year man landed on the moon.

How does one know, what truly will be the ultimate in the conquest of the skies.

Well, the first jet flew, the prototype, in 1969, people forget that.

It's a sixties airplane, and then it didn't enter service until 1976.

Steve Bohill-Smith was a British Airways Concorde pilot for six years.

How come in the last century we used to be able to fly from London to New York in just over three hours,

and now it takes seven and a half hours?

That's not progress, is it?

So what are the flight times of today's subsonic passenger jets

compared with future supersonic aircraft?

Take for example the Sydney to San Francisco route.

The distance between the two is 7,419 miles.

Currently, subsonic planes make that journey in roughly 13 and a half hours.

Future supersonic planes are aiming to fly at Mach 2.2.

That's 1,688 miles per hour, which would make the flight time nearly four and a half hours.

It was Concorde however that displayed the glamour of high-speed flight

and the plane was supposed to revolutionize the commercial aviation industry,

Everybody wanted to come up and see us in the cockpit.

Celebrities used to sit where you're sitting and chat away.

But by the end of the 20th century,

the world's only supersonic airliner faced an increasing number of problems.

One of the issues that Concorde faced was the sonic boom it created when it broke the speed of sound.

This meant it was only allowed to fly across the ocean.

There were reports that the sonic boom was rattling and damaging property.

There were, according to some scientists, environmental concerns that the plane's high altitude

would result in its exhaust fumes doing more damage to the ozone layer than regular jets.

Concorde's small passenger capacity meant airlines struggled

to spread the high running costs across its 100 or so tickets.

The planes also required specialist flight and maintenance crews, which were an additional cost.

Fuel was another problem, particularly once oil prices began to go up in the 1970s.

The Concorde burnt nearly 100 tons of fuel flying from London to New York

and two tons just taxiing onto the runway.

Its fuel capacity limited the plane to trans-Atlantic journeys.

Then in July of 2000, an Air France Concorde crashed just outside Paris

after puncturing a tire and fuel tank on take off.

113 people died and the entire Concorde Fleet was grounded for more than a year.

While the Concorde did fly again, the crash, as well as the 9/11 attacks

which hit the aviation industry as a whole, compounded the many issues that the plane was already facing.

Ultimately though, it was the Concorde's business model that didn't work.

It's small, aging and expensive fleet of planes would have been too costly and unprofitable

for the airlines to improve or re-build, and under the weight of political and economic pressures,

its flying days were over.

Today, passenger aircraft still travels at speeds similar to those at the start of the jet age.

But there are some who are trying to change that.

One American company called Boom is planning on making supersonic transport a reality.

We're like a re-invention of Concorde half a century later with more modern technology,

so the aircraft can be more affordable and available to more people.

Boom is one of a handful of startups in the process of creating a new commercial supersonic aircraft,

which its founders hope will be 30 percent more efficient than the Concorde.

Its first flight is scheduled for 2023.

Research and development for the Concorde - they spent hundreds of millions of dollars.

How much is it going to cost to make your plane?

It's certainly not a capitally unintensive venture, but what's different now versus Concorde

is Concorde with 100 seats on the airplane and a $20,000 ticket price

could not work on very many routes for very many people and so 14 only ever entered service.

When you get the fares down to business class prices, so think $2,500 each way across the Atlantic,

and you right size the airplane, so 55 seats, smaller vehicle, works on more routes

and we could see a market for 1,000 to 2,000 of those airplanes which means

a much greater opportunity to earn back the development costs.

Even with an improved business model, how do you solve the problem of the sonic boom?

The sonic boom issue I think is really overblown, but we're baselining supersonic flight over water only.

Boom is aiming to produce a plane 30 times quieter than Concorde's,

while NASA is attempting to reshape the conventional design of a fixed-wing aircraft to solve the issue.

NASA is also working on creating a quieter supersonic commercial plane

with American aero and defense company Lockheed Martin.

However, even if the sound is reduced, there are still concerns that new jets will harm the environment.

That's because much of the development is focused on modifying existing engines

that still exceed global fuel emission limits.

There are also some industry experts that believe supersonic planes

may not be the leader in aviation technology for long.

In the early stages of development for commercial supersonic transport, Boeing actually won

the initial design contract but had to stop development after their funding was cut four years later.

Now, the American manufacturer is back in the game, developing a new hypersonic plane.

We are looking at potentially really, really high-speed travel, Mach 5 speeds,

which is a step function change in what some of the subsonic or supersonic jets would do.

So how quick is hypersonic?

Hypersonic planes will be traveling at Mach 5, five times the speed of sound.

That's 3,836 miles per hour.

Meaning the plane would take just under two hours to complete the Sydney to San Francisco journey,

around two and a half hours quicker than supersonic aircraft.

But hypersonic technology for commercial travel is still decades away.

There's a lot of technology challenges that you have to overcome,

and then there's also just the business model around hypersonic flight.

Is there a market?

To get a commercial aircraft to travel at the speed of sound is a feat of incredible engineering,

and if manufacturers can also sustain and expand their fleet while continuing to make money,

then this is an industry set to reach new heights.

Hi guys, Tom here, thanks very much for watching.

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