Chilling video recorded by passengers before fatal New York helicopter crash

A video has emerged showing passengers seated as a helicopter took off on a flight which ended in tragedy when it crashed in New York City's East River on Sunday.

Trevor Cadigan, reportedly a video journalist who died in the accident, posted footage to his Instagram account of those on board a helicopter looking excited, smiling and giving a thumbs up as the aircraft lifts off the ground, US media reports.

He then changes the camera view so the clip captures their perspective as they rise higher into the air.

A video shared on social media as the helicopter is lifting off the ground

The accident involving the Eurocopter AS350 occurred shortly after 7pm on Sunday.

The pilot survived but all five passengers on board died.

The camera is turned around to show the view as the aircraft takes off.

Investigators yet to speak to pilot

According to Reuters, federal investigators probing the deadly helicopter crash have not yet spoken with the pilot who warned of engine failure before the chartered aircraft crashed into the icy water, killing all five passengers.

National Transportation Safety Board (NTSB) officials on Monday said they are also looking into why the floatation devices installed on the helicopter did not stop it from sinking, and whether the harnesses used to secure passengers on the sightseeing photography tour contributed to their deaths.

A helicopter is hoisted by crane from the East River onto a barge, Monday, March 12, 2018, in New York. Source: Source: AP via AAP

"Shortly before the crash, the pilot radioed ATC, air traffic control, declaring an emergency due to engine failure," Bella Dinh-Zarr, the NTSB board member leading the probe, told reporters near the site where the Eurocopter AS350 chartered by Liberty Helicopters of New Jersey was pulled from the water on Monday.

"We have not yet spoken with him yet. We hope to be able to," Ms Dinh-Zarr said, adding that she was unable to confirm news media reports, citing unnamed law enforcement sources, that the pilot told investigators a passenger's bag may have accidentally activated the helicopter's emergency fuel shut-off switch.

Commercial helicopters typically have the switch in case the engine catches fire, according to Jeremy Conley, a flight instructor at Helicopter Flight Training Inc in Ronkonkoma, New York.

National Transportation Safety Board (NTSB) investigators examine part of a helicopter on March 12, 2018, that crashed into New York's East River. Source: NTSB via AAP

The New York Police Department identified the pilot as Richard Vance, 33.

At least two of the passengers were dead when rescue divers got to the scene, officials said.

The other three, who had to be cut from their safety harnesses, were declared dead at the hospital.

Vance freed himself from the wreckage and was later discharged from a hospital.

Victims identified by police

Police identified the dead as Brian McDaniel, 26; Trevor Cadigan, also 26; Carla Vallejos Blanco, 29; Daniel Thompson, 34; and Tristian Hill, 29.

An image made from an undated video released by WFAA in Dallas, Trevor Cadigan, a former WFAA intern and son of WFAA production manager Jerry Cadigan, is seen. Source: AP via AAP

McDaniel and Cadigan were tourists from Texas and Vallejos Blanco was from Argentina.

The other two were employees of the helicopter company, the New York Daily News said.

This undated photo provided by Dallas Fire-Rescue shows officer Brian McDaniel. Source: AP via AAP

Cadigan shared a video on his Instagram social media account of what appeared to be himself and others smiling and laughing as they took off in the helicopter on Sunday evening.

McDaniel was a firefighter and Cadigan a video journalist, the New York Daily News reported, citing unnamed police officials.

Video of Sunday's crash appeared to show the helicopter's rotors spinning solely on momentum instead of engine power as it crashed, Mr Conley said.

The Federal Aviation Administration has no record of any accidents or incidents involving the helicopter that crashed or Vance, according to Jim Peters, an FAA spokesman.

Liberty Helicopters said in a statement it was "focused on supporting the families affected by this tragic accident," adding that it was cooperating with investigators.

The company has been involved in at least two other crashes, according to news accounts.

They included a midair collision with a small plane in August 2009 over the Hudson River that killed nine people and in July 2007 when a helicopter went down in the Hudson with a pilot and seven passengers aboard.

All of them survived.