There may be some confusion regarding altiutde restrictions on departure or arrival when a revised clearance is received.
This is partly because as of 22 November, 2007 there was an Ammendment to ICAO PANS-ATM.
Below is my summary condensed into a small table, hopefully for easier recollection, followed by several references or official sources.
There really are TWO situations, in TWO possible locations: Inside the US and outside the US (ICAO)
Situation #1 - this applies both in the US and outside the US:
>> "Level Restrictions issued by ATC"
- I'm going to rename these "VERBAL Restrictions", to differentiate from PUBLISHED Restrictions such as those on SIDs and STARs.
- Rick's 'Gouge':
- "All VERBAL Restrictions issued by ATC MUST BE REPEATED in subsequent level clearances to remain in effect.
- In other words: "If not repeated, the previous verbal restriction is CANCELLED.
- This is the same under both US and ICAO rules.
- Examples are given in the references.
Situation #2 - different under US and ICAO rules:
>> "SID or STAR level restrictions PUBLISHED in association with specific waypoints"
- Rick's 'Gouge':
- ICAO: Pilots must always COMPLY with the PUBLISHED level restrictions unless explicitly cancelled by ATC.
- US: Altitude restrictions on PUBLISHED SIDS and STARs ARE CANCELLED if previously issued altitude restrictions are omitted if the altitude to maintain is changed or restated. Note that in the US this is the same as "VERBAL" restrictions.
- Examples are given in the references.
Summary
If a new clearance includes a repeat of a previous altitude restriction (whether verbal or published), obviously that previous or published restriction still applies.
If a new clearance includes the term "...via the XYZ [SID or STAR] ...", the published restriction(s) still apply.
If a new clearance includes a specific cancellation of a previous altitude restriction (whether verbal or published), obviously that restriction is cancelled.
What is confusing to remember is:
Does a previous altitude / level restriction apply if not repeated in a new clearance?
'Verbal' restriction
Published restriction
US
Cancelled
Cancelled
ICAO
Cancelled
Still Applies
I like memory jogs: So here's one: I P A "ICAO - Published - [still]Applies"
(all other situations, they're cancelled)
Of course, "When in doubt, ask", but after reviewing the sources below, this should help in reducing the level of doubt or confusion.
If you have any further input, comments or suggestions on this topic, please e-mail me: here
Disclaimer: "The information on this web site is just my personal opinion, is not guaranteed to be accurate and is not endorsed by any airline or official agency."