Oregon Public Broadcasting

Federal documents revealed Wednesday allege that extra weight could have contributed to a helicopter crash that killed nine men last year.

An attorney representing Oregon firefighters’ families Thursday says there could be mechanical or engine problems too.

Attorney Robert Hopkins says he is reviewing the National Transportation Safety Board’s investigation notes. The notes allege the company was lax on updating maintenance records.

Robert Hopkins: “We want to look at the engines more carefully, and the whole fuel system, to see if that played more of a role than has been talked about at depth. Any of that could explain a loss of power and what happened in the crash sequence.”

In a statement, Carson Helicopters said this report is just “one step” in the investigation.

And in the report, the Grants Pass helicopter company claims investigators miscalculated the temperature at the time of the crash – that could change the weight restrictions.

NTSB wouldn’t comment on the documents released, saying only that a final report will be issued after gathering additional evidence and holding public meetings.