NEW YORK — A helicopter that crashed into the East River off New York City during a sightseeing tour last fall, killing three people, was carrying too much weight, according to a federal report released today.

The National Transportation Safety Board report doesn’t conclude what caused the crash; a determination was expected in about two months.

But the report said the Bell 206 chopper had a capacity of 3,200 pounds. The estimated weight at takeoff including all five passengers and fuel was 3,228 pounds, the report said. Federal investigators also weighed the helicopter after it was pulled from the river and estimated it could have been as heavy as 3,461 pounds, but that figure included soggy cushions and other water trapped in the aircraft after it was raised.

Pilot Paul Dudley reported that he asked people for their weights and calculated that they would not be too heavy, according to the NTSB report, but the surviving passenger said the pilot did not ask and didn’t calculate the total weight.

The helicopter sputtered and crashed shortly after takeoff from a riverbank heliport on Oct. 5, 2011. It sank 35 feet below the surface of the slow-moving water off 34th Street in midtown Manhattan, a few blocks south of the United Nations headquarters.