I think we are in danger of becoming over-complicated here. If you are cleared to depart on a SID, then both the lateral (route) and vertical (alt/FL) requirements of the SID must be followed, until or unless you are cleared otherwise. Any subsequent clearance cancels that part (i.e. vertical or lateral) of the SID.
With this in mind, and unless I have misunderstood his first post, it seems to me that
oapilot is effectively asking two questions:
Q1) If, on handover after Departure, you are cleared to an altitude (which may happen to be the next altitude on the SID), what is your subsequent vertical profile in the event of a Comms failure?
A1) This revised clearance cancels and replaces the vertical profile of the SID. So you are no longer cleared to continue with the stepped climb profile of the SID, unless it was restated as part of the new clearance.
Q2) If no climb clearance is given on handover, do you still continue with the SID stepped climb profile ... ?
A2) No new clearance has been given so of course you continue with the existing clearance and follow the SID.
MATS Part 1 (CAP493) sets out the principles involved here and
Section 1, Chapter 4 Control of Traffic reads as follows:
7 Amendments to Clearances
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. Controllers must be aware, therefore, that if the original clearance included a restriction, e.g. “cross ABC FL150 or below” then the issue of a revised clearance automatically cancels the earlier restriction, unless it is reiterated with the revised clearance.
7.2 Similar care must be exercised when a controller issues a clearance, which amends the vertical profile of an aircraft on an SID. For example, “climb FL120” automatically cancels the vertical profile of the SID. If the profile contains a restriction that provides vertical separation from conflicting traffic on another SID, the restriction must be reiterated, e.g. “climb FL120 cross XYZ 5000 feet or above”, unless separation is ensured by other means.
7.3 Similarly, when controllers issue instructions which amend the SID route, they are to confirm the level profile to be followed, e.g. “fly heading 095, climb FL80” or “route direct EFG, stop climb at altitude 5000 feet”.
JD
