Investigators on Thursday recovered the black boxes from a passenger plane whose mid-air collision with a military helicopter over Washington's Potomac river killed 67 people, as rescuers pulled victims' bodies from the freezing water.

US President Donald Trump launched a political attack blaming diversity and inclusion policies championed by his Democratic predecessors for causing the incident.

Trump's politicization of the tragedy came as the National Transportation Safety Board (NTSB) said it had recovered the cockpit voice recorder and flight data recorder from the Bombardier jet operated by an American Airlines subsidiary that smashed into an Army Black Hawk helicopter late Wednesday.

"The recorders are at the NTSB labs for evaluation," the agency said in a statement to AFP.

According to a New York Times report, staffing was thin in the control tower at Reagan National Airport, where the airliner was about to land when the collision occurred. 

One controller, rather than the usual two, was handling both plane and helicopter traffic, the Times quoted a preliminary Federal Aviation Administration report as saying.

A fireball erupted in the night sky and both aircraft tumbled into the icy Potomac, leaving rescue crews with the grim, difficult task of searching for bodies in the dark and cold.

Over 40 bodies had been recovered as of Thursday evening, according to US media reports.

Trump politicizes crash

Trump, who took office 10 days ago, turned a press conference on the disaster into a platform for his crusade against diversity, equity and inclusion or DEI — a series of often decades-old measures meant to combat racism and sexism across the United States.

Accusing his Democratic predecessors Joe Biden and Barack Obama of having kept good employees out of the aviation agency in pursuit of DEI, he claimed: "They actually came out with a directive: 'too white.' And we want the people that are competent."

The passenger plane was carrying 64 people and the Black Hawk had three aboard.

The collision — the first major crash in the United States since 2009 when 49 people were killed near Buffalo, New York — occurred as American Eagle Flight 5342 from Wichita, Kansas came in to land.

Reagan National is a major airport located a short distance from downtown Washington, the White House and the Pentagon. The airspace is extremely busy, with civilian and military aircraft a constant presence.

Trump opened his White House press conference by speaking of the nation's anguish.

However, he then launched into an extended broadside against DEI, aiming directly at Biden's openly gay Transportation Secretary Pete Buttigieg.

"He's run it right into the ground with his diversity," Trump said.

The message was hammered home as Trump's Vice President, JD Vance, and new Defense Secretary, Pete Hegseth, took turns at the podium to repeat — without evidence — the hard-right theory that diversity measures keep capable Americans out of responsible jobs.

Asked again by reporters whether he was blaming workplace diversity for the crash, Trump answered, "It could have been."

Buttigieg responded on X, calling Trump "despicable."

"As families grieve, Trump should be leading, not lying," he said.

Democratic Senator Chris Murphy posted that Trump's comments "blaming the FAA's hiring of women and black people for the crash — was disgusting."

"He's in charge. This happened on his watch," Murphy said.

Trump doubled down, however, later issuing an official memo directing the government to investigate "deterioration in hiring standards" under Biden and "replacement" of anyone unqualified.

Skaters among victims

Among those on the airliner were several US skaters and coaches, US Figure Skating said. Officials in Moscow also confirmed the presence of Russian couple Evgenia Shishkova and Vadim Naumov, who won the 1994 world pairs title.

Two Chinese citizens were also among the victims of the crash, state news agency Xinhua reported Friday in Beijing, citing the Chinese embassy.

The force of the collision soon made it clear that survivors were unlikely.

"I just saw a fireball and it was gone," one air traffic controller was heard telling a colleague after communication with the helicopter was cut.

Transport officials said both aircraft were on standard flight patterns on a clear night with good visibility.

And Hegseth said the chopper had "a fairly experienced crew that was doing a required annual night evaluation."