ICAO Equipment codes
Over at American we recently started using CPDLC. On our flight plan we have both the J4 and J5 equipment listed on the 757.
They both appear on the release.
J4 is CPDLC FANS 1/A VDL Mode 2
J5 is CPDLC FANS 1/A SATCOM(Inmarsat)
We had SATCOM in the aircraft. I am curious if the listing of J4 was a misprint or we need both to compliment each other.