NEW YORK -- Authorities using sonar in the search for the missing engine from US Airways Flight 1549 detected something about the size of the massive aircraft part deep in the frigid, murky Hudson River on Tuesday, but divers ran out of daylight before they could locate the object.
Crews will resume their search today. Police have already located many pieces of debris from the flight, including 35 flotation seat cushions, 12 life jackets, 15 pieces of luggage, two briefcases, 11 purses, 15 suit jackets and shirts, four shoes and two hats, according to NYPD spokesman Paul Browne.
The missing left engine, however, is the most coveted prize. Investigators will examine it along with the plane's attached right engine to better understand how the jet failed Thursday after hitting a flock of birds. All 155 people survived the crash landing on the river.
New York Police Department harbor officers working with a sonar expert got a reading on an object 16 feet long and 8 feet wide in about 60 feet of water. The engine is about the same size as the object picked up by sonar.
Swift currents made it impossible to drop a robotic device with a video camera to confirm whether it is the engine, and evening fell before divers could find anything.
The developments came as hero pilot Chesley "Sully" Sullenberger attended President Barack Obama's inauguration. All the media-shy Sullenberger would say is, "I'm not allowed to say anything."
Since the crash landing, the NYPD has recovered more than 40 pieces of the aircraft, including four window exits and an access panel door. All the debris and passengers' belongings are being turned over to the National Transportation Safety Board for its investigation into the crash landing.
Two days before the emergency landing, the same plane experienced a compressor stall while in flight. Passengers aboard the flight that left LaGuardia Airport on Jan. 13 reported hearing loud bangs from the right side of the plane. A short time later the situation appeared to return to normal and the flight continued on to Charlotte, N.C.
The compressor is essentially a fan that draws air into the engine and helps create thrust for the jet. A compressor stall is a situation of abnormal airflow resulting from a stall of the blades within the compressor. Compressor stalls can vary in severity from a momentary engine power drop to a complete loss of compression requiring a reduction in the fuel flow to the engine.
The stall will no doubt be looked at as the investigation moves forward, but pilots and aviation experts doubt the malfunction made the plane more vulnerable to the bird strikes that are believed to have imperiled the Airbus A320.
NTSB spokesman Peter Knudson said that the board planned to interview the pilot who was at the controls of the aircraft during the earlier incident. But he noted that investigators so far have not uncovered "any anomalies or malfunctions."
Several experts said that a compressor stall in one engine generally doesn't create much of a problem and is unlikely to have factored into the later crash-landing. And they added that the engine likely would have been closely analyzed before the plane was cleared to fly again.
Basil Barimo, vice president for operations and safety for the Air Transport Association, said compressor stalls are fairly benign events. "They are not something that brings down an airplane," Barimo said.
Retired Delta Air Lines pilot Joe Mazzone, who has flown planes that had compressor stalls, said he doesn't believe a compressor stall could have created or added to Thursday's total engine failure.
"If you have a big Canadian goose ingested in those engines, I would bet the farm that's what caused the engines to quit," Mazzone said. "The compressor stall would be a totally different issue unrelated to those birds."
Associated Press Airlines Writer Harry R. Weber contributed to this report.