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

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).