Pilot 'had been flying erratically' and 'did not know where he was' before helicopter crashed into New York City building

A pilot who died when his helicopter crashed into a New York City skyscraper had been flying erratically and said he did not know where he was shortly before the accident, a report has found.

A preliminary report by the National Transportation Safety Board (NTSB) said Tim McCormack had asked air traffic controllers for permission to return to a heliport on East 34th Street and then changed course and altitude several times.

The 58-year-old came within 500 feet of the heliport before reversing course and striking the 54-story AXA Equitable Centre on Seventh Avenue a few blocks north of Times Square.

No one in the building or on the ground was injured.

The NTSB said after taking off from the heliport on June 10 Mr McCormack had radioed that he did not know where he was.

New York Mayor Bill de Blasio said earlier this month that to fly into tightly controlled airspace above midtown Manhattan the pilot would have needed approval from the air traffic control tower at LaGuardia Airport.

Mr McCormack was a commercial pilot who had flown for American Continental Properties since 2014, the company said.

The weather on the day of the crash had been grey and rainy and the report said Mr McCormack had waited in the heliport lounge for two hours continuously checking weather conditions on a tablet computer.

Before he departed for the Linden airport in New Jersey he told staff he saw "a 20-minute window to make it out," the NTSB report said.

The Agusta A109 helicopter had departed from Amenia in upstate New York earlier in the day with Mr McCormack and one passenger and stopped for fuel in Poughkeepsie before landing in New York City.

The passenger, who also was a pilot and was not aboard when the helicopter crashed, said the earlier flights had been uneventful.

The twin-engine, seven-seat helicopter was manufactured in 2000 and had been inspected last month.

Mr McCormack held a commercial pilot certificate with a helicopter rating issued in 2004 and was a certified flight instructor but he was not instrument rated.