Air India crash mystery deepens after report

While the preliminary report on the Air India crash that killed 241 people on board and 19 on the ground has offered some explanations, it has also left many questions unresolved

RAT
APU

LAST SECONDS OF FLIGHT 171 

13:38:39 LOCAL TIME
Boeing Dreamliner 787-8 departs Ahmedabad for London Gatwick

13:38:42
Plane reaches maximum recorded speed of 180 knots (333km/h)

Fuel switches for left and right engines inexplicably move from “run” to “cut-off” position one after another about one second apart

Cockpit voice recording captures one pilot asking “why did you cut off?” – to which the other pilot replies “did not do so”

13:38:47
Ram Air Turbine (RAT) – emergency power source that can run hydraulic systems – deployed

13:38:52
Left engine fuel switch moves back from ‘cutoff’ to ‘run’

13:38:54
Air inlet door of Auxiliary Power Unit (APU) opens to supply vital power to aircraft systems

13:38:56
Right engine fuel switch also moves from “cutoff” to “run”

Left engine relights and starts to recover – right engine relights but cannot stop its “core speed deceleration”

FUEL SWITCHES
‘Run’ position

“Cutoff” position
Fuel to engines instantly cut off

Stop lock mechanism requires pilot to lift switch before changing position

13:39:05
One pilot transmits “Mayday Mayday Mayday”. Air traffic controller enquires but receives no response

13:39:11
Aircraft’s flight data recorders stop recording

Source: India’s Aircraft Accident Investigation Bureau
Picture: Getty Images
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