Monday, November 7, 2011

Recreation of USAIR Flight 1549 which landed on the Hudson

How Sullenberger Really Saved US Airways Flight 1549
by Rick Newman (Summary)
Feb 3, 2009
When airplanes crash, it’s usually because a bunch of unexpected things go wrong all at once, or one after the other. Obviously something dramatic went wrong with US Airways Flight 1549, which lost power in both engines and crash-landed on the Hudson River on January 15. But a lot went right, too.  Capt. Chesley Sullenberger has earned plaudits for “heroism,” but that oversimplifies what it took to land the crippled Airbus A320 and get all 150 passengers off safely, before the plane sank. 

 A clear division of labor in the cockpit. From the time the engines stopped producing thrust – presumably because they ingested birds – Sullenberger and Skiles had about three minutes before the powerless plane glided back to earth. And the cockpit would suddenly have become an intense environment to work in. Once the pilots chose their course, they would have started to prepare for a water landing. All in three minutes. As captain, it was Sullenberger’s job to figure out where to land the plane. No doubt he considered returning to New York’s LaGuardia airport, where the plane had taken off from, or to another airport, before realizing that the Hudson was his best bet. Meanwhile, it would have been First Officer Skiles’s job to hurry through a set of checklists with procedures for restarting the engines. 

A textbook landing. It appears that Sullenberger landed Flight 1549 on the Hudson much as he would have landed on a runway – but without engine power, and with far less margin for error. “It’s very important in a water landing to fly the aircraft onto the water as slow as possible,” says Don Shepperd, a Vietnam-era fighter pilot and co-author (with the writer of this article), of Bury Us Upside Down: The Misty Pilots and the Secret Battle for the Ho Chi Minh Trail. “The faster you hit, the more likely the plane will cartwheel or the fuselage will disintegrate.” Too slow, however, and the plane could lose lift and “stall,” causing the nose to pitch down into the water uncontrolled. “Once the decision was made to ditch,” Shepperd says, “it was a magnificent piece of aviation professionalism.” 

 The water landing was obviously shocking to those on board - yet mild compared to what could have happened. “I believed the impact would be violent but survivable,” wrote one passenger, who happened to be a pilot for another airline. “It was much milder than I had anticipated. If the jolt had been turbulence, I would have described it as moderate.”
 Buoyancy. Once in the water, Flight 1549 sank slowly. The plane obviously floated long enough for everybody to get out. A competent cabin crew. The pilot tends to get all the glory, but the “Miracle on the Hudson” also required flight attendants who directed passengers to the right exits and kept panicky people calm as they scuttled out the doors. 
“The winds and waves are always on the side of the ablest navigators,” wrote historian Edward Gibbon in the 18th century. He didn’t know Sully or Skiles. But then again, he did.