India on Monday ordered its airlines to examine fuel switches on several Boeing aircraft models while South Korea ordered a similar measure on Tuesday, as scrutiny intensified of fuel switch locks at the centre of an investigation into a deadly Air India crash.

Air India's inspection of the locking feature on the fuel control switches of its existing Boeing 787 aircraft found no issues, an internal communication circulated within the airline said."Over the weekend,

When the fuel control switch has to be cut off, the pilot flying will say, fuel control switch left, confirm. So, after the confirmation is made by the second pilot, the pilot monitoring will cut off (the switch).

A black-box recording of dialogue between the Air India flight's two pilots indicates it was the captain who turned off switches that controlled fuel flowing to the plane's two engines, the Wall Street Journal reported on Wednesday,