Investigators said that an air traffic controller had instructed the Black Hawk crew to pass behind a nearby passenger jet, but that information might have got lost.

WASHINGTON — Officials said that all on board the American Airlines flight from Wichita, Kansas, and a U.S. Army Black Hawk helicopter from Fort Belvoir army base were killed when the helicopter collided on Jan. 29.

That transmission was interrupted — it was stepped on,” said Jennifer Homendy, chair of the National Transportation Safety Board.

The Black Hawk helicopter may have been flying with “bad data” and didn’t hear all air traffic control instructions before colliding with a passenger plane, officials said.