alf5071h :
There is an ICAO code for the SSJ, it is SU95 . (there since more than a year )
interestingly there is no SU30 in ICAO, the SU-30 ICAO type designator is SU27, to complicate things many Suhkoi type designators do not follow common ICAO designations , (do not ask me why they do this
) hence adding another possible layer of confusion , (e.g. a SU-39 is for ICAO code a SU25 , a SU-47 is for ICAO SU37 , while the real SU-37 is for ICAO a SU27.. etc)
Search
It would appear that the ATS system (the computer software used) aircraft types database was not ICAO , but rather local, and that unknown types for the system could not be entered. Hence the " logical choice" to enter another Sukhoi type .
For a low trained, low pay assistant entering flight plans in a computer , a Sukhoi is a Sukhoi. To his defense, and if you type Sukhoi in google you get fighters, not civil airliners.
Interestingly during the debrief, , nobody in Jakarta ACC said they knew Sukhoi was making civil airplanes and that one was in the country.