Jeppesen don't normally derive anything - they use the data supplied by the State authority
I happen to have a question regarding this fact.
If those of you who have access to Jeppview could take a look at the VOR 30R approach in Montpellier (LFMT), and then compare it to the official one published by the French authority:
https://www.sia.aviation-civile.gouv..._AD-2.LFMT.pdf (last page).
Jeppesen has voluntarily displaced the final descent point from 6.6NM of FJR to 6.3 NM (the FAF stays at the same place though), thus changing the final approach path angle from 3.00° to 3.13°. I have absolutely no clue to why they would do such a thing, and this is the only case I am aware of.
I agree it doesn't change much, but I don't understand why Jeppesen would go to the trouble of calculating a new approach path, altitudes, etc...
Many thanks to those who can help me shed some light on this.