Flying at Near-Supersonic Speeds
One of the many unique features of the Sonic Cruiser is the placement of the twin engines. The plane's engine housing will be blended into the rear of the aircraft. This is in stark contrast to the under-the-wing engine configuration of most commercial airliners.
To push the Sonic Cruiser to 0.95 Mach and possibly faster, Boeing will initially install two 777-class engines in the Sonic Cruiser. (Mach is the speed of sound, or about 740 mph/1,190 kph). However, Boeing is not being specific about what type of 777 engines it will use. One example of such an engine is the Pratt & Whitney 4098, which generates 98,000 pounds (44,452 kg) of thrust. The Sonic Cruiser will probably be slightly smaller than a 777 aircraft, which seats 305 to 394 passengers. The lightened load, in addition to the plane's design, will allow it to travel at near-supersonic speeds.
The use of 777-class engines is likely a temporary fix until one of three major aircraft-engine makers -- Rolls Royce, General Electric or Pratt & Whitney - - develops an engine specific to the Sonic Cruiser's needs and configuration.
Traveling at 0.95 Mach, the Sonic Cruiser will be the second fastest commercial aircraft in the world, and 15 percent faster than most commercial aircraft. Only the Concorde, which flies faster than Mach 2, will be faster than the Cruiser. Boeing estimates that the Sonic Cruiser will shave one hour off of every 3,000 miles (4,828 km) traveled. The increased speed will get passengers to their destinations 20 percent faster.
Speed doesn't come cheap. While the Sonic Cruiser saves time, it uses significantly more fuel to do it. It's estimated that the Sonic Cruiser will burn anywhere from 15 percent to 20 percent more fuel than conventional aircraft. Boeing believes the added fuel cost will not be felt by the airlines. Boeing officials say that the operating costs for the aircraft will be equal to those of any other aircraft made around the same time.