February 27, 2012

On February 9, 2012, NAV CANADA, implemented a major change in Canadian ATC procedures that will require aircraft to comply with published SID/STAR altitude restrictions unless they are explicitly cancelled by ATC. Canada is making this change in an effort to implement procedures that conform to the International Civil Aviation Organization (ICAO) standards. While about 70% of ICAO member states utilize the standard procedures, certain countries, such as the United States do not.

In Canada, an aircraft that is assigned a SID/STAR, and then assigned a higher/lower altitude is still expected to comply with any published altitude restrictions on that SID/STAR while climbing/descending to the new assigned altitude unless ATC specifically states “ALL STAR ALTITUDE RESTRICTIONS CANCELLED.”

This change differs from U.S. ATC procedures contained in AIM section 4-4-10g, which state that any new altitude clearance cancels any previous altitude clearance and any published altitude restrictions on a SID/STAR unless the restrictions are restated by the controller.  Aircrew should add this as a special briefing item prior to traveling to any airport in Canada with published conventional or RNAV STARs/SIDs.

While some SID/STAR charts may contain a note regarding this difference, even if they do not, the requirement to comply with altitude restrictions still exists per the Transport Canada AIM.

In general, NBAA recommends:

  • If the FAA is providing ATC service, follow FAA procedures, even if over Canadian airspace.
  • If Canada is providing ATC service, follow Canadian procedures, even if over U.S. airspace.
  • When in doubt, ask ATC

Review the FAA InFO Message (30 KB, PDF)

Comparison of FAA and NAV CANADA STAR Phraseologies

The following table contains a comparison of FAA and NAV CANADA STAR phraseologies. It is understood that the FAA intends to introduce CLIMB VIA phraseology similar to DESCEND VIA phraseology described in this table. NAV CANADA intends to remain compliant with ICAO procedures regarding published SID/STAR altitude restrictions when SIDs with multiple altitude restrictions are introduced in Canada.

ATC Instruction – FAA
FAA Requirements

DESCEND VIA (STAR designator)
Requires the aircraft to navigate laterally and vertically to meet all published restrictions depicted in the STAR.(Aircraft already following a STAR)


Unless restrictions are re-issued, the aircraft may descend unrestricted to the assigned altitude.

Requires the aircraft to comply with published restrictions and may be used in lieu of re-issuing individual restrictions.


ATC Instruction – NAV CANADA
Canada/ICAO Requirements

VIA (STAR designator) DESCEND TO (altitude) or CLEARED (approach procedure)
Clearance via a STAR authorizes the aircraft to follow the STAR lateral track only. Once ATC issues descent or approach clearance, published altitude restrictions above the assigned altitude remain mandatory unless specifically cancelled by ATC.

(Aircraft already following a STAR:) DESCEND TO (altitude)
Published altitude restrictions above the assigned altitude remain mandatory unless specifically cancelled by ATC.DESCEND TO (altitude), ALL STAR ALTITUDE RESTRICTIONS CANCELLED

Examples of ATC phraseology for cancelling altitude restrictions.

For more information contact the NBAA Operations Service Group at (202) 783-9451 or info@nbaa.org.