Unprofessional, you decide.
I have been following on another forum the increase of users of the SBS-1, which for the unaware is a receiver of Mode-S transmissions which are then listed for the user on a computer screen. To my knowledge spotters are not the only users of this equipment with a number of airlines having purchased some to locally track their fleets.
Today the following entry was noted by one user.
400659 F**KALL
Needless to say the callsign element was typed in full and I’ll leave the interested readers to check the hex code on the G-INFO site as to the company in question.
While I am not aircrew myself, but ex ops for a now deceased American company, I feel that this puts the crew member who entered that into his FMC as unprofessional.
Of course that callsign is contrary to CAA and ICAO requirements which state the aircraft ATC callsign should be used and if none then the aircraft registration substituted in its place.