The site of Air India plane crash in Ahmedabad (Photo: PTI)
The investigation into the Air India flight 171 crash has zeroed in on the movement of the engine fuel control switches, following an analysis of the Boeing 787’s flight and voice data recorders, the Air Current reported on Tuesday.
According to the aviation industry publication, there may have been a possibility of improper movement of fuel control switches in the cockpit.
The fuel control switches have two positions – run and cutoff, the report claimed, adding that the switches are only moved on the ground during engine start and shutdown at the end of a normal flight.
The switches may also be moved if an engine needs to be manually shut down or restarted by the crew in the event of an engine failure in any phase of the flight.
Moving a fuel control switch from run to cutoff in flight would cause the fuel supply to stop flowing to the associated engine, resulting in its immediate shutdown and the loss of any thrust, the report stated.
The end would also stop the two electrical generators on each engine from providing power to many of the aircraft’s systems and some of its cockpit displays.
The fuel control module underneath the jet’s throttle handles holds the two switches, which are guarded with brackets on either side to prevent accidental movement. A metal stop lock mechanism on each switch is designed to require the flight crew to lift each switch past the stop in order to move it.
In the event of an engine fire, the fuel control switch for the affected engine would illuminate in red, providing a key visual cue to the crew, according to the report.
Sources told the Air Current that the available information on the black boxes could not rule in or out improper, inadvertent or intentional actions that preceded or followed the apparent loss of thrust before the aircraft crashed.
US aviation safety expert John Cox said a pilot would not be able to accidentally move the fuel switches that feed the engines.
“You can’t bump them and they move," he said.
Cox added that if a switch was shut off, the effect would be almost immediate, cutting off engine power.
Meanwhile, Reuters quoted sources and stated that the investigation has not raised any immediate concerns over mechanical failure, and there has been no bulletin to airlines recommending changes to 787 operations.
The London-bound Boeing 787 Dreamliner, which started losing height after reaching an altitude of 650 feet, crashed moments after takeoff from Ahmedabad, India, killing 241 of the 242 people on board and the rest on the ground.
India’s Aircraft Accident Investigation Bureau is leading the probe under international rules.
Most air crashes are caused by multiple factors. The investigation is focusing at least partly on engine thrust, Reuters reported last month.
Air India on Friday said it has paid the compensation to families of nearly two-thirds of the victims who died in the plane crash in Ahmedabad.
Of the 242 people onboard, 241 were killed, while the total death toll stood at 260, including casualties on the ground.
Soon after the crash, Air India parent Tata Sons announced that it would provide Rs 1 crore each to the families of each person who died in the crash.
Source: News18