When beginning a decent do you need to ask permission or advise the controller ? I generally just decend because I am under my own navigation, however, I am never really sure if this is the correct way to do it. At the CALSCREAM 6 event on Sunday, I was decending into Vancouver which was not very busy but what if I was decending into LAX ? Any advise appreciated.Mark.

Own Navigation is Lateral only.. if you start descending on your own into LAX, you'll most likely crash into someone..If the controller tells you "Cross XXX at YYY" then you can descend at your discretion, so long as you're at XXX altitude by YYY fix. If the controller doesn't specifically tell you to descend, you are required to stay at your previous altitude, because the last altitude instruction you were given is Climb and MAINTAIN whatever altitude you're at. Mike

In Europe, we don't use the phrase "climb _and maintain_", we just tell to "climb". But still, the same restriction is in use. And lateral restriction exists, in USA too. The pilot has some navigation restriction (usually the end of filed route) and he can't continue from there without clearance. Very simple, ehh?A couple of examples:(The normal situation; Note that the clearance limit is set now to VTI by controller)Controller: "Finnair 846 Quebec, proceed direct VTI, when ready descend to cross VTI at FL70, expect visual approach runway 15."Pilot: "Proceed direct VTI, when ready descend to cross VTI at FL70, expect visual approach runway 15, Finnair 846 Quebec."(Pilot wants to start the descent, he has to ask permission; Remember, usually controller knows the right timing of descent.)Pilot: "Finnair 826 Foxtrot, ready for descent."Controller: "Finnair 826 Foxtrot, descend to cross KENON at FL100."Pilot: "Descend to cross KENON at FL100."(The route given in clearance (the flight plan route this time) is on end and controller haven't given any instruction to continue.)Pilot: "Finnair 834 Hotel, joining the hold at LAKUT."Controller: "Finnair 834 Hotel, fly heading 080, contact Helsinki Radar on 119.1."Pilot: "Heading 080, contact Helsinki Radar on 119.1, bye."

Thanks for the info, I will put into practice on my next VATSIM flight.Mark.