By Jonathan Kaminsky and Eric M. Johnson
SEATTLE, March 21 (Reuters) - Video footage shows a news helicopter that crashed this week in a crowded area of downtown Seattle, killing two people, spinning off a building before nose-diving to street level, the National Transportation Safety Board said on Saturday.
U.S. officials were still trying to piece together what caused the 11-year-old Eurocopter AS350, which had been stationary for about 15 minutes atop a news station's building, to pitch forward and nosedive shortly after a brief lift off.
The helicopter rotated about 360 degrees counter-clockwise before pitching forward and continued to rotate until it disappeared from the cameras' view, the NTSB said.
The chopper then burst into flames in an area dotted with museums and the iconic Space Needle, killing the pilot and a photographer on board. Three vehicles on the street caught fire but their occupants escaped alive, although one was severely burned.
All major components of the aircraft were recovered from a 340-foot (104-meter) radius of the main wreckage, said the report, which gave no indication of the cause of the crash. The NTSB said it was in the early stages of the investigation.
The report was based upon recordings from three security cameras provided to the NTSB by the Seattle Police Department, along with witness statements and other findings.
In January, the NTSB said helicopter operations were among its priorities for improving transportation safety. It said over 500 deaths since 2004 in accidents involving choppers for search and rescue missions, medical transport and commercial operations was "unacceptably high."
The motorist, who suffered burns over 20 percent of his body, on Friday underwent the first of what could be multiple surgeries, local media reported.
No flight plan was filed before the helicopter's ill-fated takeoff en route to the Seattle suburb of Renton, the report said.
A manager at the Terminal Radar Approach Control (TRACON) facility near Seattle said it had no exchange with the pilot, an official familiar with the federal investigation told Reuters.
"Air traffic says this guy was on a (Visual Flight Rules) flight and he wasn't talking to them," he said, adding VFR is common in helicopter flying and standard as long as the weather allows for it.
Saturday's findings based upon video footage back up earlier reports by investigators at the scene of the crash and witness accounts that said the helicopter spun and made an unusual sound. (Reporting by Jonathan Kaminsky in Olympia, Washington, and Eric M. Johnson in Seattle; Editing by Lisa Shumaker)