ARFOR;
PJ Have you a view on the SATCOM in EMER ELEC (RAT or NOT) config?
The AOM/FCOM does not show SATCOM or ACARS available in the EMER ELEC Config, RAT or no RAT QRH procedures.
If the engines are supplying hydraulic power for the emer gen, VHF1 and HF1 are available. HF1 is not available under any other configurations; VHF1 is.
Remember, the services which must be available are under emergency circumstances and which must contemplate using the emergency electrical (hydraulic) generator run either by the engines or the RAT (very bad circumstances) right down to the ship's batteries, are prioritized towards the safety of the aircraft, not communications. "Aviate, Navigate, Communicate" is a bread-and-butter way of expressing these priorities. Ship's batteries are certified for about 30 minutes (if I recall), even under these severely reduced services.
The QRH indicates under Navigation equipment, that:
IR 1 & 3 are available until the batteries exhaust themselves - about 30 minutes;
IR 2 is available for 5 minutes;
ADR 1 is available until the batteries exhaust themselves
ADR 3 is available under engine hydraulic power (driving the emer gen) but is not available otherwise;
ADR2 is not available.
SATCOM/ACARS etc would be among the first services to be lost, by design, under the EMER ELEC Config.
The APU battery cannot be used for any other purpose other than starting the APU.