The Army helicopter that collided with a passenger jet last week in Washington had its tracking technology turned off at the time of the crash, U.S. Senator Ted Cruz told the New York Times. The technology allows air traffic controllers to better track the movement of an aircraft.

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.