There were 64 people on board the plane and the three soldiers in the Army helicopter, according to DC Mayor Muriel Bowser.
First responders are battling cold and windy conditions as they work to recover bodies from the Potomac River in near-freezing temperatures.
The passenger plane was American Airlines Flight 5342, operated by PSA Airlines, traveling from Wichita, Kansas, to Reagan National, the Federal Aviation Administration said in a statement. The Bombardier CRJ700 regional jet was due to land at the airport Wednesday night when it collided midair with the US Army helicopter as it approached Runway 33, according to the FAA and defense officials.
The US Army Black Hawk helicopter was on a training flight at the time, Joint Task Force-National Capitol Region media chief Heather Chairez told CNN.