Investigators hope equipment aboard a helicopter might provide clues about why it crashed into New York's East River, killing a British passenger and seriously hurting a British couple and a New Zealand woman.
A member of the U.S. National Transportation Safety Board, Mark Rosekind, spoke at a briefing Wednesday.
Rosekind said engine monitors and GPS navigation equipment may have stored useful information.
He also said winds may have been a factor. A weather reporting station at nearby LaGuardia Airport had reported gusts of up to 23 mph (37 kph).
Rosekind said one of the helicopter's main blades was broken. But it's not clear whether it broke before or after it crashed.