How about a flight to London from New York in less than four hours?

That was the promise in 1973 when the supersonic Concorde was first introduced.

That plane did fly for nearly three decades, until it was finally grounded in 2003.

Now, a number of companies are working to bring supersonic travel back to the skies in the next three years.

Smaller 45-seat planes will cruise at 1,451 mph, or Mach 2.2.

The technology is there, so now these companies just have to win the battle of economics and fuel costs.

The other question is demand.

But there are also the optics: how many high rolling international bankers and CEOs will actually choose to take the expensive flights?

Bottom line: for now, investors are funding the supersonic project, so stay tuned.

For more information about changes in air travel, check out:

• The Average Price of an Economy Plane Ticket is Decreasing
• Airlines Introduce Lie-Flat Seats in Business Class
• Will We See the Return of High Speed Travel?

Keep reading for more travel tips.