A 3-D model created by The Times visualizes the helicopter pilots’ field of view minutes before a fatal crash with a jet in Washington.

Investigators trying to determine what caused last week’s deadly midair collision between a US military Black Hawk helicopter and an American Airlines plane near Washington, DC, briefed lawmakers Thursday on what they’ve learned after combing through data from both aircraft and air traffic control.

The investigation into the deadly midair collision between an American Airlines jet and a Black Hawk helicopter is revealing a critical safety system on the helicopter was turned off at the time of the crash.

The black hawk helicopter involved in the deadly collision with an American Airlines jet over Washington, D.C. has a crucial safety system turned off at the time.

Radar evidence proves that the Black Hawk helicopter was not flying low enough during collision with American Airlines Flight 5342.