NTSB says preliminary investigation into midair collision will take 30 days

WASHINGTON -- Recovery efforts were ongoing Friday morning following the nation's first major commercial airline crash since 2009.

Crews are now awaiting heavy machinery, including cranes, from the Army Corps of Engineers, Coast Guard and private contractors before they can extract additional collision victims, sources familiar with the operation told ABC News.

The hope is the equipment will be in position to begin raising pieces of the fuselage as soon as Friday but the operation is expected to last at least through the weekend.

Dive teams ceased operations on the Potomac on Thursday after recovering all of the bodies they were able to without moving the fuselage, according to two sources familiar with the operations.

On Wednesday night, a regional American Airlines passenger jet and a Black Hawk military helicopter collided over Washington, D.C.

The flight data recorder and cockpit voice recorder -- known as black boxes -- from the American Airlines plane have been recovered and are at a National Transportation Safety Board lab.

DC PLANE CRASH: A timeline of the deadly collision

More than 40 bodies have been recovered so far, among them is the body of one of the soldiers from the Army Blackhawk helicopter.

Additional bodies and human remains will need to be extracted from the wreckage once it is lifted to the surface of the river.

Crews are bracing for the possibility some of the victims will not be recovered because of the fireball that resulted from the collision, the sources said.

President Donald Trump said there were no survivors from the crash in remarks Thursday morning, calling the crash a "tragedy of terrible proportions."

"Our hearts are shattered," Trump said in a press briefing at the White House, after holding a moment of silence. "Our prayers are with you now and in the days to come."

"We are all searching for answers," Trump said, adding, "We do not know what led to this crash" but have "some pretty good ideas."

The NTSB has said their preliminary report into what caused the crash will take approximately 30 days and that it will take "a year or more" to get a final probable cause.

Todd Inman, a member of the National Transportation Safety Board, appeared on "Good Morning America" on Friday, saying that the NTSB "will be on scene here doing all the recovery of the perishable evidence we need for as long as it takes."

"The preliminary report, we believe, will be out in 30 days but in case of these major investigations, it will take a year, if not more, for us to come to a final probable cause," Inman continued. "The most important thing is, the work doesn't just end then. We make recommendations so that we don't have tragedies like this again in the future."

Inman said the NTSB has started the process of extracting data from the voice recorder.

"The data recorder itself has thousands of data points and they all have to be synchronized against a lot of other things that happened in the plane," Inman said. "The voice recorders have to be what is called 'auditioned' among a number of people so that there's complete agreement of how the transcript will come out. We also look for ancillary noises. Maybe a boom or thud or crack or something in the cockpit. Those things are going on concurrently, along with the fact we have several hundred people in the field looking at every other aspect of this investigation."

Inman also said that it is way too early to make any conclusions about what exactly caused the crash.

"The only conclusion I know is last night we met with several hundred family members who lost their loved ones in the Potomac," he said. "We don't need that to happen anymore. We're going to work. We're going to continue. We're going find out what happened and we're going try to stop it from happening again."

DC PLANE CRASH VICTIMS: What we know about those on AA Flight 5342, Army Black Hawk

American Airlines CEO Robert Isom remains in Washington, D.C., on Thursday to support the families and help authorities.

"Out of respect for the families, we are not sharing the names of the two pilots and two flight attendants at this time, but our thoughts and prayers go out to their loved ones," Isom said.

The Black Hawk helicopter, which had three soldiers on board, carries a black box with a voice and flight data recorder.

Authorities were still looking for the helicopter's black box recorder, Defense Secretary Pete Hegseth said Friday on Fox News Channel.

Other factors in the crash, including the helicopter's altitude and whether the crew was using its night vision goggles, are still under investigation, Hegseth said.

"It was a fairly experienced crew that was doing a required annual night evaluation," Hegseth said Thursday. "They did have night vision goggles."

Jimmie Cummings, a spokesman for the Army's Combat Readiness Center at Fort Novosel, Alabama, said that just like all soldiers who must meet regular qualifications for their weapons, Army aviators have to meet annual qualifications, regardless of their flight experience. For aviators, that means flying under different conditions, which could mean flying in daytime or nighttime.

It was based at Fort Belvoir, Virginia, according to an Army official.

"We are working with local officials and will provide additional information once it becomes available," the official said.

On Wednesday at Reagan Airport, a supervisor made the decision to combine two controller positions into one position. This decision was made 40 minutes earlier than normal because the supervisor determined that the traffic was low enough to combine, according to a source with direct knowledge.

This position handles local arrivals into Reagan and helicopter traffic when it's combined. This happens routinely when aircraft volume goes down. Reagan is not understaffed, the source added.

The air traffic controllers' union said in a statement that it's working with all federal agencies and "stands with the highly trained, highly skilled" workforce that "keeps the United States as the gold standard for aviation safety."