My understanding was that ELTs had automatic function -other than manual, impact and water. Could someone deactivate all, including fixed ELT near tail?
Secondly, does Cospas-Sarsat monitor the southern Indian Ocean area?
re cospas-sarsat, yes.
But given all of the other recent evidence (that the satcom may have been transmitting after the a/c would have been out of fuel) it is less likely that it crashed and more likely that it landed, so the ELT is unlikely to have been automatically activated.
Now if one of the pax had their own 406 MHz PLB....