Newly released CCTV footage has revealed the mid-air collision between a Black Hawk helicopter and an American Airlines jet over the Potomac River.

The video shows the passenger aircraft flying steadily when a rapidly approaching helicopter crosses its path, colliding with it and triggering a massive fireball, killing at least 67 people.

This tragic incident occurred on the night of January 29, as Flight 5342 was making its final descent into Ronald Reagan Washington National Airport.

The plane involved was a Bombardier CRJ-700, operated by American Eagle - a regional affiliate of American Airlines - with around 60 passengers on board.

Authorities said the helicopter was on a training mission.

The National Transportation Safety Board has launched a three-day investigative hearing to determine the factors that led to the fatal crash. The first session took place on Wednesday, July 30.

Ronald Reagan National Airport is in the centre of the nation's capital, near major federal institutions including the White House and Congress. It is also across the river from The Pentagon, the US Department of Defence, in Arlington, Virginia.