Ornis, I read the Aviationist article and they quote "Although this is still debated, according to several pilots the ACARS transmissions can be switched off by the pilot from inside the cockpit, by disabling the use of VHF and SATCOM channels".
FE_Hoppy, I have just re-read my FCOM. No way is explained to turn off the SATCOM. Yes each ACARS is customized to an airlines specs. I have carefully read through all I could find on available specs and it did not appear to offer downloading of flight plan data to the airlines ops. Yes, we can all uplink a plan.
Would you agree that with the acars and transponder off then no data apart from the ping response came from the aircraft after the incident?