An American Airlines regional jet collided with a U.S. Army Black Hawk helicopter on Jan. 29. Both aircraft plunged into the Potomac River near Reagan Airport.

The Army Black Hawk helicopter involved in the fatal midair collision in Washington, D.C., had a tracking system turned off, Sen. Ted Cruz, R-Texas, said.

A key safety system was turned off in a US army helicopter when it crashed into an American Airlines flight last week, killing 67 people.