A preliminary analysis of the flight data and voice recorder on board a Black Hawk helicopter leading up to the collision with a commercial flight over Washington, DC, on January 29, indicated the helicopter’s altimeter may have been inaccurate and the pilots may not have heard some calls from the Reagan National Airport control tower,

The NTSB is turning the focus of its investigation into the Jan. 29 collision on what the Black Hawk pilots could see and hear.

National Transportation Safety Board officials said Friday that a key transmission from Reagan National Airport’s air traffic control tower may not have been heard by Army Black Hawk helicopter pilots just before they were collided with an American Airlines regional jet last month,

Military helicopter pilots on a training flight over Washington, D.C., did not hear air traffic control directions to pass behind a passenger jet heading its way, investigators revealed on Friday. With American Airlines Flight 5342 from Wichita,

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, and may have had “bad data” on the altitude they were flying at,