Engine sounds heard before Alaska plane crash

JUNEAU, Alaska (AP) — Two witnesses described hearing a high-pitched sound from the engine of a small, for-hire airplane before it crashed last year on Alaska's Kenai Peninsula, killing all 10 people aboard.

Another reported seeing a puff of black smoke from the air taxi's engine area.

The witness statements were included in investigative documents released by the National Transportation Safety Board on Wednesday.

The documents do not provide any theories or analysis of what investigators believe might have caused the crash in Soldotna. A final report on the July 2013 accident that killed the pilot and two families from South Carolina is pending.

A weight and balance study looked at different scenarios, including one described as closely approximating the weight and balance of the plane during the flight. It calculated the plane as slightly over the maximum gross weight for which it was certificated.