Boeing's was perhaps the most revolutionary airliner design since the
Concorde was produced a quarter of a century ago. The Sonic Cruiser was slated to be the fastest
subsonic airliner ever built, with a cruise speed in excess of
Mach 0.95—over 700 miles per hour! With an estimated operating range of 9,000 miles, it would finally make direct New York-Singapore, London-Perth, and Tokyo-Johannesburg flights a reality.
The Sonic Cruiser represented a grand dichotomy in airliner design from the bigger is better philosophy. Airbus was still going for size, with its 500-plus-seat Airbus A380 that promised to replace the Boeing 747 as the undisputed champion of high-density intercontinental transportation. Boeing, on the other hand, offered an aircraft with less than half of the A380's capacity (200-250 seats), but with earth-shattering performance. Their new plane had the potential to shave an hour off of transatlantic and transcon flights, and two hours off of transasian and transpacific flights: enough to get the attention of Joe Business Traveler, who would undoubtedly love to leave New York after breakfast and get to LA well in time for lunch.
Ever since the Concorde came out in the 1970's, Boeing had been attempting to engineer a superior American rival to the world's only successful (in that it flies) SST, and for a short time were touting their government-sponsored Boeing 2707 project as The Future of American Aerospace. The oil crisis that struck around the time of the Concorde's completion made the SST market look somewhat bleak, so Boeing had to push their dreams of supersonic air travel aside and concentrate on high-density cash cows for the major airlines of the world.
The main problem with Concorde, and with most supersonic aircraft in general, is that aircraft wings tend to produce absurd amounts of drag as their speed approaches the sound barrier. To compensate for this extra drag, high-speed aircraft have to be outfitted with incredibly powerful engines, usually with afterburners built in. These engines consume tons of jet fuel, and carrying all that extra fuel makes the plane heavier, increasing its drag even more. It's a catch-22 of monstrous proportions, and one of the reasons that the Concorde doesn't make any money, even when a one-way ticket across the Atlantic costs several thousand dollars.
In designing the Sonic Cruiser, Boeing utilized the new technology of computational fluid dynamics. With computers, they could model the drag effects that different wing shapes have within a high-speed airflow, and then alter the shape of the virtual wing until it achieves optimum aerodynamics. In the Sonic Cruiser's case, Boeing settled on a huge delta wing that spreads out at its rear end, looking much like the extended swing wing on a B-1 bomber.
This new wing design, coupled with newer advanced composites, gave the Sonic Cruiser the potential to break all aircraft performance standards in the modern airline industry—without drinking jet fuel like a frat boy drinks Bud Light. Boeing planned to power this airborne starship with a pair of simple turbofan engines, similar to those used on the Boeing 777.
Unfortunately, Boeing cancelled the Sonic Cruiser program in December of 2002, replacing the program with what is now known as the Boeing 787 "Dreamliner."