The investigation played out as authorities released a frantic 911 call that captures the drama of the flight from almost the minute the ill-fated jetliner took off. A man from the Bronx called 911 at 3:29 p.m. Thursday, three minutes after the plane took off.
"Oh my God! It was a big plane. I heard a big boom just now. We looked up, and the plane came straight over us, and it was turning. Oh my God!" the caller said.
Investigators encountered more treacherous conditions Saturday as they embarked on the delicate task of trying to hoist the jet from the Hudson River without damaging the airplane. Big patches of ice had formed around the plane Saturday morning as the temperature fell to 6 degrees.
National Safety Transportation Board member Kitty Higgins said the agency and salvage company officials were still trying to work out the logistics of how to lift the 80-ton plane onto a barge. The partially submerged plane is tethered to a sea wall in lower Manhattan.
Investigators began interviewing the pilot, Chesley B. "Sully" Sullenberger, and his co-pilot for the first time Saturday, said NTSB spokeswoman Bridget Serchak. Sullenberger glided the crippled aircraft into the river on Thursday afternoon when he couldn't make a nearby airport, saving the lives of all 155 people on board.
Crews will use a crane to raise the plane a few feet at a time to let the water drain out. If the deluge doesn't flush out on its own, bilge pumps will be used to get ride of the rest. Load cells will be attached to each wing to measure the plane's weight as it comes out of the water.
After the plane is up, it will be taken to a location in New Jersey for examination. The plane's wingspan is wider than the barge, so the wings will hang over the side as it is moved across the river.
The delicate task of removing the aircraft was not the only work playing out on the Hudson River. Divers and sonar operators hunted for the missing left engine in the cold, dark and murky river.
The engine was lost when Flight 1549 splashed down after colliding with birds. Exactly where, though, was a mystery. U.S. Army Corps of Engineers vessels and city police department boats were to resume the search Saturday, probing the sediment of the river bottom along a 4 1/2-mile stretch from the point of impact to the southern tip of Manhattan.
Authorities want to closely inspect the engines to figure out how exactly the birds caused the plane to fail so badly and so fast. They may also look for feathers in the engines to determine the bird species, helping prevent future mishaps.
The lost engine could be 30 to 50 feet down, obscured in thick sediment. Conditions are so murky that police and fire department divers will have to feel about by hand.
"There is hardly anything to see because of the sediment," said Thomas M. Creamer, chief of the operations division of the New York District of the U.S. Army Corps of Engineers, one of the groups brought in to help with the search.
Under the direction of the police department, the National Oceanic and Atmospheric Administration used sonar to look for the engine. That technology can produce a picture of the river bottom, but its range is limited.
"It is going to take time," Creamer said. "It is a large area. Things move around quickly."
Meanwhile, the pilot's status as a national hero rose by the hour as he took a congratulatory call from the president and president-elect, earned effusive praise from passengers on the plane and become the subject of a growing global fan club.
Sullenberger was in good spirits and showing no outward signs of stress from the ordeal, a pilots union official said. He has not spoken publicly since the accident.
Survivors of the accident began returning to their families.
When Beverly Mills arrived at the Charlotte, N.C., airport Friday afternoon, her husband greeted her with a half-dozen red roses. The card tucked in the flowers read: "I will always love you." Mills recalled standing outside the plane in the cold and waiting to be rescued when she saw her briefcase float past with her wallet, credit cards, cell phone and passport.
The type of engine on the Airbus 320 is designed to withstand a 4-pound bird strike, said Jamie Jewell, a spokeswoman for CFM International of Cincinnati, the manufacturer. That's fairly typical for commercial airliners and their engines, although larger Canada geese can exceed 12 pounds.
Higgins also suggested that part of the investigation will be to "celebrate what worked here," something of a rarity for an agency that focuses on figuring out what went wrong in a disaster.
The investigation began as new details emerged about why the pilot chose to land the plane in the river - and not at two nearby airports. The pilot twice told air controllers that he was unable to make the proper turn after reporting a "double bird strike." The tower believed Sullenberger meant that both his jet engines had been damaged by bird impacts.
The accident also raised questions about whether airports around the country are doing enough to deal with bird flocks.
The agency that operates New York City's major airports said it has a multimillion-dollar program to chase birds off its property, but can only do so much to protect planes once they are in the air.
The Port Authority of New York and New Jersey said it kills thousands of birds every year in the marshy waterways and tidal flats that surround its two major airports in Queens, and uses guns, pyrotechnics and hawks to drive away birds.
Among the other tactics: Bird eggs are coated in oil to prevent them from hatching. Nests are removed. The agency also plays recordings of bird distress calls, and landscapers remove shrubs and trees that might be attractive to certain species.
Sometimes aircraft have to take evasive action to avoid flocks of geese. Other times, it's too late and they can only hope for the best.
One Boeing 737 pilot writing about a strike in a safety report described the smell of burnt feathers and seabird after a gull was sucked into his rear engine during a landing at LaGuardia in 2004.
If an engine takes in a large bird - or several birds at once - fan blades may break, causing an imbalance in the engine's rotation and severe vibrations, said Kevin Poormon, who tests the ability of aircraft engines to withstand bird strikes. Those vibrations conceivably could be strong enough to cause an engine to come loose from its mounting, Poormon said.
Passengers heaped more praise on Sullenberger, co-pilot Jeff Skiles and their crew for their handling of the landing and evacuation.
"There could not have been a better scenario to this disaster. It could have been much worse. God really had to be with him as well," said Shae Childers, 38, of Gaffney, S.C., who was recovering from hypothermia Friday at a New York hospital.
Sullenberger's wife, in an interview outside their California home, called him "a pilot's pilot" and said talk of him being a national hero was "a little weird."
At a City Hall ceremony Friday to honor those who went to the aid of the passengers, Mayor Michael Bloomberg said Sullenberger's actions "inspired people around the city, and millions more around the world."
The NTSB is working with the FBI and the city to obtain any video evidence recorded by city residents. The Coast Guard is trying to ensure that fuel still in the aircraft is contained, if possible.
Associated Press writers Colleen Long and Samantha Gross in New York, Michael J. Sniffen and Joan Lowy in Washington, Mitch Weiss in Charlotte, N.C., and Mike Baker in Raleigh, N.C., contributed to this report.