Engines
As jet engine power and reliability have increased over the last decades, most of the widebody aircraft built today have only two engines. A twinjet design is more fuel-efficient than a comparable trijet or four-engined aircraft. The increased reliability of modern jet engines also allows aircraft to meet the ETOPS certification standard, which calculates reasonable safety margins for flights across oceans. The trijet design has been effectively dismissed due to higher maintenance and fuel costs, and only the heaviest widebody aircraft today are built with four engines (the Airbus A340, Airbus A380 and Boeing 747).
The Boeing 777 twinjet features the largest and most powerful jet engine in the world, the General Electric GE90, which is 128 inches (3.25 m) in diameter. This is almost as wide as the entire fuselage of a Boeing 737 at 148 inches (3.76 m).
The massive maximum takeoff weight of the Airbus A380 (560 tonnes (1,200,000 lb)) would not have been possible without the engine technology developed for the Boeing 777 (such as contra-rotating spools). The Trent 900 engine pictured, used on the Airbus A380, has a fan blade diameter of 116 inches (2.95 m), only slightly smaller than the GE90 engines on the Boeing 777. An interesting design constraint of the Trent 900 engines is that they are designed to fit into a Boeing 747-400F freighter for relatively easy transport by air cargo.
Read more about this topic: Wide-body Aircraft
Famous quotes containing the word engines:
“America is like one of those old-fashioned six-cylinder truck engines that can be missing two sparkplugs and have a broken flywheel and have a crankshaft that’s 5000 millimeters off fitting properly, and two bad ball-bearings, and still runs. We’re in that kind of situation. We can have substantial parts of the population committing suicide, and still run and look fairly good.”
—Thomas McGuane (b. 1939)