Preliminary data from the Washington DC air collision that killed 67 people gives conflicting information about the altitudes of the plane and military helicopter at the time of the crash.

In a news conference, officials from the National Transportation Safety Board (NTSB) said that data from the jet’s flight recorder showed its altitude as 325ft, plus or minus 25ft, when the crash happened on Wednesday night.

But preliminary data in the air traffic control tower showed the Black Hawk helicopter at 200ft at the time. The discrepancy has yet to be explained.

NTSB member Todd Inman also revealed that the jet’s flight recorder showed a change in its pitch but did not say whether this meant the pilots were trying to avoid the crash.

It comes as the third soldier who died onboard the Black Hawk has been named as Captain Rebecca M Lobach.

Final moments before the crash

Information from the jet’s black boxes has been recovered but the helicopter’s is taking more time to retrieve because it became waterlogged after the aircraft plunged into the Potomac River.

Brice Banning, the investigator in charge of the case, said the plane’s crew “had a verbal reaction” in the last moments before the crash.

He said the data recorder showed “the airplane beginning to increase its pitch… sounds of impact were audible about one second later, followed by the end of the recording”.

The NTSB also said five people were working in the air traffic control tower at the time of the crash, after reports that staffing levels were “not normal”. The NTSB did not comment on whether there was an appropriate number of staff on duty.

The collision near Reagan National Airport in Washington was the deadliest US aviation incident in almost 25 years.

The 60 passengers and four crew on the American Airlines flight from Wichita, Kansas, as well as the three soldiers on the army helicopter were killed.

Last soldier named

Some 38 of the bodies have been identified, with authorities saying they expect to recover all the victims – but the plane’s fuselage will probably have to be pulled from the water to retrieve the rest.

More information about those who died has also emerged. The US Army identified Captain Rebecca M Lobach, from Durham, North Carolina, as the third soldier who died in the crash.

The names of the other two soldiers were released on Friday, but Ms Lobach’s name was withheld at the request of her family.

They said she was “a bright star in all our lives”. Ms Lobach served as a White House military social aide and was pictured alongside President Joe Biden and Ralph Lauren during the awarding of the fashion designer’s Presidential Medal of Freedom earlier this year.

Army officials have said the helicopter crew was highly experienced and familiar with the congested skies around Washington DC.

‘They still want answers’

In an emotional news conference, Mr Inman said he has spent hours with the victims’ families since the crash.

“I don’t want to have to meet with those parents like that again.”

The families, he said, are struggling. “Some wanted to give us hugs. Some are just mad and angry,” Mr Inman said.

“They are just all hurt. And they still want answers, and we want to give them answers.”

Read more: What do we know about the victims of the Washington air crash?

Mr Inman became frustrated at points during the news conference, noting that the NTSB has made “several hundred” recommendations to improve aviation that have not been acted upon.

“From tragedy, we draw knowledge to improve the safety for us all. That’s what we’re doing right now, we’re dealing with tragedy, but we need to improve safety,” he said.

“You want to do something about it? Adopt the recommendations of the NTSB. You’ll save lives.”

The recovery operation is continuing in Washington DC, with the remains of 42 people retrieved from the river so far.

As many Americans remained shocked by the deadly crash, a second aviation accident took place on Friday night in Philadelphia, Pennsylvania.

An air ambulance slammed into a busy junction, killing all six people on board, including a child who had just undergone treatment at a hospital, and at least one person on the ground.