The pilot, identified as Tim McCormack, said in the crash, law enforcement officials said.
"Pilots must have an instrument rating to fly in bad weather," said FAA spokeswoman. "This pilot did not have an instrument rating."
An instrument rating that requires about 100 or more hours of additional training on top pilot training, CNN aviation analyst Mary Schiavo said.
At the moment, it is believed to be "flying blind" in clouds or heavy fog under the direction of air traffic control.
At the time of Monday's flight, moderate to heavy rain falling in the city, and visibility at Central Park which down to 1
The helicopter took off from East 34th Street Heliport about 1:32 pm Monday, New York police commissioner James O'Neill said.
Based on interviews investigators conducted at the East 34th Street Heliport on Manhattan's East Side, he said he had a 5- to 7-minute read break in the rainy weather to take off. The pilot did not refuel at the heliport, the source added.
Once the pilot was in the air, he radioed back to the heliport and said he needed to return. The last time the pilot communicated with the heliport he conveyed he was unsure of his location, the source said.
The pilot then flew around Manhattan's mid-late Manhattan Battery Park on the southern tip of the island and then, somewhere around the streets in the 40s, heading to midtown Manhattan before crash-landing, the law enforcement source said.
McCormack had flown for American Continental Properties, the company that owns the helicopter, for five years, according to a company statement.
McCormack received his business pilot's license in 2004, according to Federal Aviation Administration Records A rotorcraft helicopter last year.
The National Transportation Safety Board released details Tuesday, May 24, 2009, due to investigators are aiming for 15 months. A preliminary report is expected in two weeks, but it does not provide a cause for the crash.
NTSB air safety investigator Doug Brazy said the helicopter had no flight data recorder or voice recorder. The aircraft did, however, contain other devices for recording data, and investigators continue to search for them, he said.
Complicating matters is the crash debris is located on a rooftop. "It's highly fragmented and a post-crash fire consumed much of the evidence," he said.
CNN's Eliott C. McLaughlin, Hollie Silverman, Shimon Prokupecz, Darran Simon, Julia Jones,
Brian Rokus, Eric Levenson, Elizabeth Joseph, Mark Morales, and Sonia Moghe contributed to this report.