[hanche]

They have a RAT (ram air turbine) that deploys automatically under specific conditions. It’s basically a turbine providing electric and hydraulic power. It was almost certainly deployed on the accident flight. It will only power the most critical equipment, though. Possibly, that does not include the ADS-B transmitter (which broadcasts position and related data).

[keepamovin]

This analysis is convincing about being able to hear the sound of the RAT from the crash video: https://www.youtube.com/watch?v=SbDJjgN7Xbo