B767 offset in china
 

How can offset be accomplish during SID/STAR phase of flight?

As far as I have ever experienced the offset is only done on the enroute phase of the flight.

it can't. The offset automatically ends when the approach begins. It makes sense if you think about it - a STAR is specifically designed to keep you safe - if you start adding offsets to them you'd see a lot of people hitting mountains.

Additionally, RNP for procedures is 1nm, so you wouldn’t be able to offset very far anyway.

Why would you want to do that?

This actually happens somewhat often out of PVG and I’ve also had it happen in PEK. You are correct that the FMC will not let you offset when you’re on a SID/STAR. However, there is a simple way around it:

Just select the fix you’re headed TO and drop it back into the TO position, then Execute. You haven’t affected your navigation/SID, but the FMC thinks you’ve now gone “direct” and are no longer on the SID.

You can now go to the RTE page and offset as usual.

Interesting. I’m curious as to why they’d want you to do that instead of just using vectors or creating another SID.

Who knows. It’s China, so I just don’t even attempt to understand the why.

Oh it can be pretty different in China…

Never flown in China. How much are you requested to offset?

Enroute sometimes 3, sometimes 5 miles... They seem to think of their (sparse) airways as multilane highways, its odd..

I’ve had 15. 3 is the norm. But when you ask for an offset for either “unable due restriction”. It’s the one and only place I’ve declared a mayday as we were deviating restriction or not. Wasn’t even acknowledged.

That's a classic, don't remember if i requested an offset or a heading due to a CB on the airway, but of course the answer was "unable due military area", to which I replied unable to proceed on route :} ... "Deviation approved":E

After being denied a lateral offset, normally an equivalent heading request would be immediately granted…

… amounting to substantial track shortening and probably equal to 20NM!