A flight to Reagan National Airport was forced to abort its initial landing due to helicopter activity in the D.C. area ... one day before the catastrophic crash that left dozens dead.

Check out the video ... Republic Airways Flight 4514 is clearly on a smooth track from Connecticut and begins its descent ... and then abruptly circles around before touching down.

In an audio recording published by LiveATC.net, air traffic control is heard warning the pilot ... "There’s a helicopter over Georgetown northbound 300 feet."

The pilot of the twin-engine Embraer ERJ 175 immediately responds .. saying they are halting the descent and "going around" to climb to an elevation of 3,000 feet.

"We had an RA with the helicopter traffic below us," the pilot adds, referring to a resolution advisory from the Traffic Alert and Collision Avoidance System (TCAS) ... meant to warn pilots about the danger of a collision.

Close call ... but luckily the aircraft landed safely 13 minutes ahead of schedule.

Of course, American Airlines Flight 5342 had a different outcome ... colliding with an Army Black Hawk helicopter during its descent to Reagan National. All 64 people on board the commercial flight and the 3 troops inside the Black Hawk died.

The NTSB confirmed Thursday night that the plane's black boxes have been recovered and will be sent for analysis down the road at the NTSB lab.