The airline confirmed Wednesday that the plane's left main landing gear touched down off of the left side of the runway. The right wing tip hit the ground as the pilots attempted to direct the plane back on course.
Sources familiar with the investigation say Flight 1402 drifted off center during its final approach to Charlotte Douglas International Airport. Investigators want to know why that happened and why the pilots elected to land after controllers apparently notified them moments before landing that the plane was not lined up with the center of runway, sources said.
Pilots will often abort the landing and go around the airport if the plane is not properly aligned.
In a statement released Wednesday afternoon, the NTSB said the autopilot was on during the plane's descent, but the pilots turned it off when the MD-82 was about 250 feet above the ground.
It's unclear why the pilots elected to do that.
American Airlines spokeswoman Andrea Huguely said the plane did not have any recent history of any autopilot or flight control problems. Hugely said the airline was cooperating with the NTSB investigation.
The interviews with the pilots will be essential to the investigation. According to the NTSB, the cockpit voice recorder continued to run while the plane was at the gate after the incident, recording over the two-hour tape and eliminating the record of the pilots' conversations as they attempted to land.
The Wall Street Journal reported Wednesday that the crew had been on duty for 14 hours before the landing, which would exceed the FAA's maximum allowable work hours.
But according to the airline and sources familiar with the investigation, the crew had been on duty for just more than 11 hours, less than the federal 12-hour maximum.
A spokesman for the union that represents the pilots said the crew may have misstated their work hours on a preliminary report, failing too take into account the time change between the West Coast, where they started their day, and the East Coast, where it ended.