January 29, 2010 — Vol. 3, Issue 1
William Langewiesche's Fly By Wire
When US Airways Flight 1549 suffered a dual engine failure moments after takeoff from LaGuardia Airport, the pilot did a remarkable job. So did the aircraft, writes William Langewiesche.
After pulling off a flawless emergency landing and evacuation in the Hudson River on January 15, 2009, Captain Chesley "Sully" Sullenberger, the pilot of US Air Flight 1549, virtually became a household name. Sullenberger did everything right, proving himself an exceptional pilot in extraordinary circumstances.
The other hero in Langewiesche's Fly by Wire: The Geese, the Glide, and the Miracle on the Hudson
is the Airbus A320. This aircraft, the first commercial passenger jet to employ a digital fly-by-wire control system, is "the most audacious civil airplane since the Wright brothers' Flyer," Langewiesche contends. By optimizing the plane's technical performance under any given set of parameters, the fly-by-wire system "radically redefines the relationship between pilots and flight."
Fly-by-wire technology had its origins at NASA's Dryden Flight Research Center in the 1970s. A decade later, Bernard Ziegler, a French engineer and former test pilot, convinced the management team at Airbus to develop an aircraft that would rely on flight control sensors and computers rather than mechanical and hydraulic systems. The fly-by-wire system would not allow a pilot to execute a maneuver that would push the plane beyond its capabilities and cause it to stall or break up. The result was an intelligent airplane that was both more automated and more forgiving of pilot errors.
Langewiesche intersperses a gripping minute-by-minute account of Flight 1549 with chapters about bird strikes, gliding, commercial airline pilot culture, and the evolution fly-by-wire technology. He contrasts "the miracle on the Hudson" with a Continental Airlines crash near Buffalo that took place a month later. When the plane unexpectedly came close to stalling, the pilot pulled back hard on the controls, overriding a safeguard system designed to prevent over-stressing the aircraft. The plane veered out of control, resulting in the deaths of all the passengers and crew aboard. The fly-by-wire control system in the Airbus A320 would not have permitted the same maneuver.
Langewiesche is careful not to present fly-by-wire as a failsafe system. He notes that it introduces the risk of complacency, which he calls the Titanic effect: "If you believe your ship is practically unsinkable, you might start charging across icebergs." He also acknowledges that an outstanding pilot like Sullenberger might well have achieved the same result in a conventional airplane, but suggests that the fly-by-wire system significantly narrowed the possibility of human error. "Sullenberger was brilliant at it [flying], as was the automation he commanded."
Read a Time Magazine interview with the author of Fly By Wire.
Article by HS