The NTSB says it has recovered all major pieces of the American Airlines plane that crashed into the Potomac River in Washington DC.
It collided with a Black Hawk helicopter on a training exercise.
Accident investigators say all debris from the helicopter has been recovered too.
All wreckage from the two aircraft is being analyzed, the NTSB says.
Both of the regional jet’s voice and data recorders has been found.
“Investigators will be looking for witness marks on the aircraft that could provide clues to the angle of collision,” the agency said.
The mid-air collision on January 29 killed 67 people close to Reagan National Airport.
Investigators are taking a very close look at the helicopter’s ADS-B surveillance system which was either turned off or was not operating properly.
So far, the safety agency has no definitive cause for the collision.
