"We're going to be looking at training, at qualifications; we have taken fuel samples, air traffic control tapes, radar data -- all of this data is part of our investigation."
According to Hersman, the flight left Teterboro Airport in New Jersey at 2:21 p.m. ET, heading north. After taking a right turn to fly south over the Hudson River, the plane took a 180-degree turn at the Statue of Liberty, flying over the East River.
As the plane, a Cirrus SR20, headed north over the East River at a speed of 112 mph, it began a left turn once it got beyond East 70th Street, traveling at an altitude of about 700 feet. The final radar showed the aircraft make a left turn a quarter-mile north of the East 72nd Street building, having dropped to about 500 feet in the air.
Hersman said that the winds were coming from the east at seven knots, with the visibility listed at seven miles.
The Federal Aviation Administration, which is assisting the NTSB with the investigation, is reviewing the tower tapes at Teterboro, as well as LaGuardia, Kennedy and Newark Liberty Airports.
Despite several reports that Lidle's plane issued a distress call before the accident, Hersman said there is no evidence of such a communication.
"We do not have any information of any mayday or distress calls, or that any other contact was made with those towers," Hersman said.
According to Hersman, the last contact between Lidle's plane and air traffic control came shortly after the plane took off from Teterboro, when Lidle or Stanger said they would be flying up and down the East River.
The NTSB documented the wreckage at the building on Wednesday and Thursday, beginning on the 40th floor, where Lidle's plane crashed shortly before 3:00 p.m. The investigation moved to the 41st floor, then the 39th and down from there.
Investigators looked on terraces and ledges for any of the aircraft's parts. A handheld GPS system was found and sent to Washington, D.C., for analysis, but Hersman said the instrument was damaged.
"This was a severe impact," she said.
All four corners of plane -- the nose, tail and both wings -- were located by the NTSB, as well as the instrument panel, which could help investigators collect more information, depending on the damage. Lidle's flight logbook was also recovered.
The engine was found and removed from the 40th floor apartment in which Lidle's plane crashed, as it will be shipped to Mobile, Ala., where the manufacturer, Teledyne Continental, is based.
The propellers were also recovered, and they will be sent to Ohio, where the NTSB will supervise further review. It is believed that the propellers were turning at the time of the crash.
The aircraft's parachute was recovered and examined by a representative of the manufacturer, and the initial investigation showed that it was thermally discharged, though it was still tightly packed following impact.
"There was significant fire that occurred post-crash," Hersman said. "We're looking at whether it could have been deployed by the crew, whether it was damaged on impact or whether there was a thermal discharge. It appears that it was thermally discharged."
The NTSB hopes to release the crash site by Friday and isn't likely to hold any more briefings until the investigation moves back to Washington.