The crew of the Army helicopter that collided in midair with an American Airlines jet near Washington's Ronald Reagan National Airport may have had inaccurate altitude readings in the moments before the crash, and also may not have heard key instructions from air traffic controllers to move behind the plane, investigators said Friday.

The crew of an Army Black Hawk helicopter that collided with a passenger jet over the Potomac River last month may not have heard parts of two radio transmissions about the location of the plane, the National Transportation Safety Board reported Friday. NTSB investigators are also looking into the possibility that the altitude reading in the helicopter’s cockpit was incorrect, Jennifer Homendy, chair of the board, said at a press briefing. “We are looking at the possibility of there may be bad data,” Homendy said. Homendy said investigators are confident,...

Black Hawk pilots may not have heard a critical directive from air traffic control to fly behind the American Airlines plane in the seconds before it collided with the jet, the National Transportation Safety Board said Friday. Seventeen seconds before the deadly Jan. 29 crash, which killed all 67 people aboard both flights, the Black Hawk was directed to pass behind the passenger jet, NTSB Chairwoman Jennifer Homendy said at a news conference. “They may have not received the ‘pass behind the’ because they were communicating with air traffic control,”...

Based on facts, either observed and verified firsthand by the reporter, or reported and verified from knowledgeable sources. Investigators said Friday that the Army helicopter crew involved in the midair collision with an American Airlines jet near Ronald Reagan National Airport may not have heard air traffic control instructions to pass behind the plane. National Transportation Safety Board (NTSB) Chairwoman Jennifer Homendy stated that a recording from the Black Hawk helicopter cockpit suggests the crew missed a crucial directive just before the Jan.