National Transportation Safety Board (NTSB) Chairman Robert Sumwalt said on Tuesday that the pilot of the helicopter that crashed with retired NBA star Kobe Bryant on board was legally prohibited from flying into the clouds, but did so anyway. The pilot's actions have been in focus in the investigation into the crash of the Sikorsky S-76B helicopter outside Los Angeles into hilly terrain. The board said pilots can become confused about an aircraft's attitude and acceleration when they cannot see the sky or landscape around them, causing "spatial disorientation."