Originally Posted by Greybeard
Electrical power supply problem? Please explain what kind of power supply problem it could be, Olivier. Are the TCAS antennas in this case considered internal or external?
IMO, it is too much reading and the wording may induce it.
The BEA is listing the two shut down cases due to "external" systems.
a) its electrical power supply => if not powered anymore, the TCAS become inop.
b) another external failure.
This CFR from ACARS is pointing to b) wrong air data, altitude, ADRs. (and much more would be said by the maintenance computer after landing).
This is also consistant with no "Electrical power supply" failure detected.
All relevant parts of any system are of course part of it. Then, this mean that those "TCAS antennas" are included inside TCA system like those SATCOM antennas are part of the SATCOM system.