Timeline of air traffic controllers issuing warnings before American Airlines plane, Black Hawk helicopter collision in DC

Air traffic controllers warned a US Army helicopter that it was getting dangerously close to an American Airlines passenger plane that was landing at Ronald Reagan Washington National Airport before the deadly collision on Wednesday night, according to a recording of the air traffic control radio exchange.Less than 30 seconds before the mid-air crash, which sent both aircraft into the icy Potomac River in the US capital, an aircraft controller radioed the helicopter – “Have you spotted the CRJ?” – referring to American Airlines Flight 5342, a CRJ 700, according to FlightRadar24.The plane, which took off from Wichita, Kan., with 64 people on board, was landing at Reagan National – traveling north toward Runway 33.The helicopter – which took off near Langley, Va., according to reports – appeared to have been flying up the Potomac prior to the crash.The collision happened at about 8:48 and 48 seconds on Wednesday night.Here is a partial reconstruction of the events that led to the crash, based on initial flight maps and air traffic control audio:...