Officials with the National Transportation Safety Board convened a hearing on the January 29, 2025 collision between a Sikorsky Black Hawk chopper and a Bombardier plane flown by an affiliate of American Airlines that killed 67 people.

NTSB board members voted on a probable cause and recommendations, with a final report expected in the coming weeks.

The investigative agency had released earlier "urgent" recommendations with restrictions on military helicopters near Ronald Reagan National Airport (DCA) when certain runways are in use.

The body also organized a three-day hearing last summer that revealed a significant discrepancy between the altitude displayed in the aircraft and its actual height.

Investigators at the meeting had compiled a list of more than 70 areas for improvement, from the staffing of the air traffic control tower at the time of the crash to communication between the two aircraft.

Among their findings, investigators discovered more than "18 reports per year on average of close calls between airplanes and helicopters near DCA in the four years before the accident."

In the Potomac River area where the collision occurred, helicopters are required to stay below 61 meters (200 feet). But the helicopter was at an elevation of 85 meters (278 feet) at the time of the collision.

NTSB Chair Jennifer Homendy said Tuesday a military helicopter's altitude readings could have a margin of error of as much as 30 meters (100 feet). But pilots were not aware of this discrepancy at the time of the accident.

Military manuals have been updated with this guideline, an Army official told the hearing Tuesday.

The US government admitted in December it was liable for the accident, according to a Department of Justice filing in a civil lawsuit against the US government and the commercial airline operating the plane.