A PSA Airlines Bombardier CRJ700 regional jet collided in midair with a Sikorsky H-60 helicopter while on approach at Reagan Washington National Airport around 9 p.m., according to the Federal Aviation Administration.
The airline was operating Flight 5342 for American Airlines, according to the FAA.
The military aircraft was a U.S. Army Black Hawk helicopter, according to two U.S. officials.
The plane had departed from Wichita, Kansas, the FAA said.
The National Transportation Safety Board is leading the investigation.