Investigator Jennifer Homendy has given details of the helicopter's final transmission.
Officials in the US say the pilot of the helicopter carrying Kobe Bryant was battling thick cloud at the time of the crash.
The former basketball star and his daughter were killed in California on Sunday, along with seven others.
The National Transportation Safety Board has revealed visibility was so poor that police choppers had been grounded.
Investigator Jennifer Homendy has been giving details of the helicopter's final transmission:
''The pilot advised they were climbing to avoid a cloud layer.
''When ATC asked what the pilot planned to do, there was no reply.
''Radar data indicates the the helicopter climbed to 23 hundred feet and then began a left descending turn.''
Tributes from fans, fellow basketball players and other public figures have been pouring in from around the world while fans congregate at a makeshift memorial for the player in front of the Lakers' Staples Center in Los Angeles.
