[ars]

It's in the article:

"Under the rules taking effect in 2021, a plane would switch to one-minute tracking automatically when systems detected it was in distress because of turbulence, mechanical difficulties or an unexplained change in course, such as during a hijacking or if the crew became unconscious.

Pilots couldn’t turn the system off after it activates automatically, ICAO said. The system would deactivate itself once the plane was flying safely again.

However, a pilot could turn off the system if it was manually activated.

The challenges tied to minute-by-minute tracking include adding computing power and internet bandwidth to process larger volumes of data. The tighter system also may require reserving more space on the flurry of satellites being launched to satisfy demands for constant internet connectivity."