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.

Boeing’s engine fuel control switches, now the center of the investigation into the fatal Air India crash in June, have been scrutinized before.

“We’re going to be doing very severe tariffs if we don’t have a deal in 50 days, tariffs at about 100 per cent, you’d call them secondary tariffs,” he added.