India and South Korea has made these instructions following global fears over the fuel switch locking mechanism associated with a deadly Air India crash in Ahmedabad which claimed 260 lives.

While Boeing and the U.S. Federal Aviation Administration (FAA) recently assured regulators and carriers that the switches are safe, many countries and airlines are taking precautionary measures.

The necessity for these actions arose after an initial investigation into the crash of Air India indicated that both of the fuel switches somehow got switched from the "run" to the "cutoff" position soon after the takeoff.

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According to media reports, one pilot questioned another for cutting off the fuel supply, and the second pilot answered that he had not done it.

The investigation cited a 2018 FAA alert that had urged — but not required — operators of some Boeing types, including the 787, to check the locking controls on the fuel switches to prevent them from being accidentally engaged.

The initial report emphasized that Air India had not made the FAA s 2018 recommendations effective, as they were not obligatory.

Following this initial investigation findings, India s Directorate General of Civil Aviation (DGCA) stated that it had directed inspections of Boeing planes, including the 787 and 737 series, after similar action by both Indian and foreign carriers.

At the weekend, Air India Group started checking the locking mechanisms on the fuel switches of its Boeing 787 and 737 aircraft. As of now, no problem had been found, a source with knowledge of the situation said. Inspections have so far covered almost all 737s and around half of 787s, with completion due in days.

Though the report expressed concern, shares of Boeing went up 1.6% on Monday as the report did not recommend specific actions for 787 operators or the GE engines used in the aircraft.