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

The Federal Aviation Administration and National Transportation Safety Board plan to brief senators Thursday on last week's midair collision between an American Airlines passenger jet and a military helicopter near Washington's Ronald Reagan National Airport that killed 67,