B737-400 cross track displacement.

[jrs2-benson]

Does anyone know how specifically the B737-400 FMC describes lateral track displacement?

I have come accross two probable answers, cross track and along track. To me, displacing track laterally sounds like cross trk displacement (INS systems use X TRK error?) but have been told that it is actually along trk displacement!


Any thought are welcome.

Thanks for reading

JRSB.