Black boxes recovered from plane in Potomac collision

Investigators on Thursday night found the black boxes for the American Airlines plane that crashed into a helicopter and fell into the Potomac Wednesday night. The items were at a National Transportation Safety Board lab for evaluation, the agency said Thursday.

What are black boxes, exactly? Formally called flight data recorders and cockpit voice recorders, the two black boxes are usually stored in the plane’s tail, according to the NTSB. The flight recorder records information about the plane’s altitude, direction of travel, and speed. The other recorder captures all radio transmissions passing through the plane’s cockpit, as well as the pilots’ voices and engine noises.

Dig deeper: Read my report in The Sift from yesterday about officials’ response to the crash, which killed 67 people.