I'm going to take one last stab at this and then consider hanging my hat up for good.....!
If you are sent direct to GIBSO for the WILLO 2D and given:
1) a conditional clearance to descend FL300, expect FL270 level GIBSO
2) descend FL290
3) a heading
4) another heading
5) clearance to descend FL270 level abeam GIBSO
6) own navigation GIBSO
7) "route direct KUMIL" before reaching GIBSO
8) descend FL180 level KUMIL
9) a heading
10) own navigation KUMIL
11) descend FL130 level GWC, cross KUMIL FL180 or below
12) descend FL110 before reaching GWC.
How many of these examples do you think means you can now ignore the previous level by or expect level instruction? Are you really going to want every single example writing down saying that the heading does not cancel the level restriction be it issued or expected? If the level restrictions are required, I can see them being said SEVEN more times in my example above. Are you really expecting there to be the RTF availability (especially in the sectors concerned in this example) to say this? Not forgetting that will be SEVEN more times to multiples of aircraft, sometimes even more if it is required every time a new heading is given.
In my head, only points 7 & 12 need the level restriction repeating if they are still required.
Let's dissect Chapter 4:
7.1 When an amendment is made to a clearance the new clearance shall be read in full to the pilot and shall automatically cancel any previous clearance.
I still do not understand how a vector is an amendment to a clearance. A vector is a tool used by ATC to provide separation, where they issue headings ALONG THE AIRCRAFT ROUTE. You are still "on route" when in the confines of the airway or within 5nm of an upper air route centreline. Going down this road then when issuing a vector, ATC should be really also confirming the route or STAR still to be expected after vectoring as the new clearance
shall be read in full.
RMC,
Which appears to confirm that if you are taken off the lateral element of a published STAR by an ATC heading instruction then the original STAR altitude is not valid unless it has been reiterated?
Points 7.2 and 7.3 are only for SIDs, so not part of this debate and bear no relevance. If it applied to STARs or even just overflying traffic following a route then it would be specified.
The discussion here centre's around the ATC publication, as I wrote in an earlier response, the UK AIP only says that issuing a level clearance cancels any previous level restrictions unless the previous restrictions are repeated, and nothing further.