This is the text from the Preliminary Report.  By its very nature, the details are subject to change and should not be relied upon. The Final Report for this incident will be issued in due course:-

On October 4, 2011, at 1525 eastern daylight time, a Bell 206B, N63Q, registered to a private owner, crashed into the East River during takeoff from East 34th Street Heliport (6N5), New York, New York. Visual meteorological conditions prevailed and no flight plan was filed for the local flight. The personal flight was conducted under the provisions of 14 Code of Federal Regulations Part 91. The helicopter sustained substantial damage to the airframe. The certificated commercial pilot and one passenger were not injured. Two passengers sustained serious injuries and one passenger was killed. The flight originated from 6N5 at 1524.

The pilot stated to NTSB investigators that he was taking friends on a local sightseeing flight. He stated that he landed at the heliport, picked up the 4 passengers, and initiated a takeoff to the northeast. The helicopter climbed to a pilot-estimated altitude between 30 to 50 feet over the East River. Shortly thereafter, the pilot experienced a problem which included a small left yaw. He then initiated a right turn to attempt to return and land at the heliport but the helicopter became uncontrolled and impacted the water. After water entry, the helicopter rolled inverted.

During the impact, three-fourths of one main rotor blade separated and was not recovered from the river. The remainder of the helicopter was recovered and transported to a hangar for examination. The engine was retained for a subsequent examination.

The pilot held a commercial pilot certificate with ratings for airplane single-engine land, airplane multiengine land, and rotorcraft helicopter. He reported a total flight experience of 2,287 hours, of which 1,500 hours were in helicopters, including 420 hours in the same make and model as the accident helicopter.

The helicopter was manufactured in 1976 and equipped with a Rolls-Royce (Allison) model 250, 400-horsepower, turboshaft engine. The most recent annual inspection was performed on October 2, 2011. At that time, the helicopter had accumulated approximately 11,580 total flight hours.