The investigation into last month's Air India crash that killed 260 people is focusing on the actions of the jet pilots, it has been reported.
Preliminary findings indicate that switches controlling fuel flow to the jet’s two engines were turned off, leading to a loss of thrust of the Boeing 787 Dreamliner shortly after take-off, The Wall Street Journal has reported.
These switches are used to start the jet engines, shut them down or reset them in emergencies.
It is unclear how or why they were turned off and whether the move was accidental or intentional, said the newspaper's sources familiar with US officials’ early assessments.
The newspaper said that if the switches were off, it could explain why the jet’s emergency power generator – known as a ram air turbine, or RAT – had been activated just before the plane crashed.
There is no immediate indication of an issue with the flight in the investigation, the outlet reported.
The report comes before a preliminary report was expected to be issued by India’s Aircraft Accident Investigation Bureau, which is leading the probe into the crash.
The Air India flight AI171 took off from Ahmedabad for a journey to London Gatwick on 12 June, yet only moments later, the plane crashed into a medical student accommodation.
All but one of the 242 passengers on board died, with further casualties on the ground bringing the death toll to at least 275.
Indian officials have released little information to the public about the investigation, which has caused some frustration with American government and industry officials.
They have also been frustrated with the slow processes of downloading, analysing and sharing the contents of the plane’s black boxes - the flight-data and cockpit voice recorders.
The black boxes were recovered in the days after the crash, one from a rooftop at the site on June 13, and the other from debris on June 16.
The Independent has contacted Air India for comment.