The Air Accidents Investigation Branch (AAIB) report said the wheel's outer bearing had seized.
The CAA said it could not comment on the crash while the AAIB inquiry continued.
The helicopter will now be taken for examination by the Air Accidents Investigation Branch (AAIB).
The AAIB said a report on their investigation would be filed in due course.
The AAIB added that all of the passenger seats had come loose from the floor of the aircraft.
The Air Accidents Investigation Branch (AAIB) said it was sending two staff to Kathmandu to assist local authorities.
The wreckage was later recovered from the seabed and transported to the AAIB headquarters at Farnborough in Hampshire.
The end of the flight might have been "far more survivable for all on board", added the AAIB.
Four inspectors from the Air Accidents Investigation Branch (AAIB) are at the crash scene carrying out an inquiry.
The AAIB report said the wheel's outer bearing had seized and "consequential damage had allowed the wheel to detach".
Several safety actions had been initiated following the incident, the AAIB report concluded.
The AAIB inquiry discovered that he had an undiagnosed condition which could cause symptoms including palpitations, tremors and headaches.
The AAIB report said the flight from Prague to Essex took off during the afternoon of 4 July 2012.
The Air Accidents Investigation Branch (AAIB) said their actions increased the risk of a fire on board the plane.
BBC: NEWS | Europe | Isle of Man | Air crew criticised for fire risk
The AAIB said it could find no evidence anything had gone wrong with the aircraft before it hit the cable.
The Air Accidents Investigation Branch (AAIB) said the crew carried out the controlled ditching due to a system failure warning.
The AAIB report suggests that the helicopter came close to being involved in a much more serious incident on Monday.
The AAIB said that the captain had inspected the right main landing gear before the flight and had not noticed any abnormalities.
The Air Accidents Investigation Branch (AAIB) said the aircraft, by modern standards, had "low stability and power margins and poor flight instrumentation".
The Air Accidents Investigation Branch (AAIB) found there was a rotor blade fault that caused them to strike the craft and separate.
Now, however, the AAIB needs the space and is refurbishing the hangar.
An Easyjet spokeswoman said no-one from the firm had been disciplined over the incident and AAIB's report "does not make any recommendations".
But although the transmission mentioned "failure", Mr Lewis, from Merseyside, sounded calm, said a report by the Air Accidents Investigations Branch (AAIB).
The AAIB report found that the cabin crew did not inform the flight crew they had moved the passengers to the back.
BBC: NEWS | Europe | Isle of Man | Air crew criticised for fire risk
Previously a military test pilot, Mr Roche was employed by a major airline as a commander on passenger jets, the AAIB report said.
The AAIB report said the mood on the helicopter was jovial and the passengers could be heard shouting and laughing, "enjoying the experience".
Crash investigators from the Air Accidents Investigation Branch (AAIB) have been at the scene and the wreckage of the aircraft has now been removed.
The AAIB was notified of the crash within minutes and a team of inspectors, including engineers, pilots and flight recorder specialists travelled to Aberdeen that evening.
Last year, a report by the Air Accidents Investigation Branch (AAIB) found no technical reason for the crash, but said a technical fault could not be ruled out.
The sheriff's findings go further than an Air Accidents Investigation Branch (AAIB) report, published in February 2009, which found no cause could be positively determined into the tragedy.
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