Yesterday, families of the victims visited the site for the first time and placed roses to remember the dead.
National Transportation Safety Board member Steve Chealander said investigators have located the steering column, or yoke; all the propeller blades; five of six deicing valves; and rubber bladders designed to protect the tail from ice.
Though ice has emerged as a possible factor, the cause has remained elusive in part because there was no distress call from the pilot, no mechanical failure has been identified, and the plane was so severely damaged.
The crew had turned on the plane's deicing system 11 minutes after leaving Newark. Shortly before the crash, they notified air traffic controllers of significant ice buildup.
Chealander said Sunday that the pilot appeared to ignore recommendations by the NTSB and his employer that the autopilot be turned off in icy conditions. The autopilot remained on until an automatic system warned that a stall could occur, pushed the yoke forward, and shut the autopilot off.
Chealander acknowledged that it was possible that the pilot overreacted by yanking the yoke back, further destabilizing the plane, but he said that was one of an almost unlimited number of possibilities.
Kirk Koenig, president of Expert Aviation Consulting of Indianapolis and a commercial aviation pilot for 25 years, said the airplane may have been in a predicament that would challenge even the most experienced pilots.
"Things happened so quickly, and they were so low to the ground that it would not have mattered if Chuck Yeager and Neil Armstrong were flying the plane; there wouldn't have been a different outcome," he said.
The plane's deicing system was apparently working, the NTSB has said. That system includes strips of rubber-like material on the wings and tail that expand to break up ice, then contract and expand again to break up new ice.
