The engines of the helicopter that crashed near Los Angeles last month, killing Kobe Bryant and eight others, showed no evidence of a "catastrophic internal failure," federal investigators say.
The interim report, issued by the National Transportation Safety Board (NTSB) on its crash probe 12 days after the accident, also said examination of the rotor assemblies found damage "consistent with powered rotation at the time of impact."
The findings, while preliminary, pointed to no obvious signs of mechanical problems that might have contributed to the fiery crash in which Bryant, 41, his 13-year-old daughter, Gianna, and all seven others aboard the helicopter perished.
The NTSB investigative update said: "viewable sections of the engines showed no evidence of an uncontained or catastrophic internal failure."
The report did not rule out that mechanical issues might yet be identified when the engines and other parts recovered from the wreckage of the Sikorsky S-76B are disassembled and more closely examined.
NTSB board member Jennifer Homendy said two days after the tragedy that clouds, fog and limited visibility reported in the vicinity of the crash would be a key focus of the investigation.
Friday's report said videos and photographs taken by the public in the area depict fog and low clouds obscuring the hilltops around the crash site, including security video footage showing the helicopter disappearing into clouds moments before it went down.
The NTSB also quoted a witness from a mountain bike trail in foothills surrounded by mist who recounted briefly glimpsing the helicopter emerge from clouds as it rolled to the left before crashing seconds later a short distance away from him.
The pilot, an experienced aviator certified as an instructor, was navigating by visual orientation, not by instrument guidance, during the entirety of the ill-fated flight, the NTSB said.