Flight Crews FAQ

1. Why did ICAO introduce a more lengthy phraseology?

The revised phraseologies were designed by controllers and pilots, just like you. While the phraseologies may seem longer to use, they are meant to allow the controllers' intent to be clearly conveyed to flight crews, with no implied meaning or expectations. There were increasing safety concerns regarding flight crew confusion during the approach and departure phases at various locations, and clear signs that these occurrences will increase as traffic grows. The new phraseology removes ambiguity in ATC clearances issued to flight crews when on SIDs or STARs.

2. If I receive a clearance using the instructions CLIMB VIA SID, or DESCEND VIA STAR, without an altitude or level, can I start climbing/descending?

This is an incomplete phraseology, you should not commence climb/descend since you have not been issued a cleared level. When using the ICAO SID/STAR procedures, the clearance to climb on the SID or descend on the STAR must include a cleared level. The correct phraseology is CLIMB VIA SID TO (level), or DESCEND VIA STAR TO (level). The guiding principle behind the phraseology is clarity and consistency with no implied expectations. If you are unclear, please confirm your clearance with ATC.

NOTE: Flight crews may encounter the use of procedures that differ from those published by ICAO. For example, flight crews operating in the U.S. national airspace system receive clearances to CLIMB VIA SID and/or DESCEND VIA STAR without a cleared level. Flight crews must remain aware of phraseology differences when operating in States that have not adopted the ICAO SID/STAR procedures.

3. Does the controller have to use DESCEND VIA STAR TO (level) every time they clear aircraft to descend?

For aircraft flying on a STAR with active restrictions, YES! When issuing level change instructions for such flights, DESCEND VIA STAR TO (level) must be used consistently whenever restrictions are still applicable on the STAR. This ensures that flight crews understand their obligation to comply with the published restrictions on the procedure.

NOTE: Please readback the full clearance, especially the assigned altitude/level, so the controller knows that you are fully aware of the issued instructions.

4. Why might a controller issue a DESCEND TO (level) clearance after previously clearing me to DESCEND VIA STAR TO (level)? What do I do?

If you are following a STAR, the controller can use the phraseology DESCEND TO (level) when there are no remaining published speed or level restrictions on the procedure. Similarly, DESCEND TO (level) will be used if you are given a vector or clearance that takes you off the STAR. If you have questions regarding your clearance, ask for confirmation from the controller.

If restrictions are intended to be cancelled it will be explicitly stated. The proper phraseology for cancelling speed and level restrictions down to the cleared level on the STAR is:

CLIMB UNRESTRICTED TO (level), or
CLIMB TO (level), CANCEL LEVEL AND SPEED RESTRICTIONS
Unless otherwise specified, the subsequent restrictions on the STAR beyond the cleared level remain valid.

If there is doubt about your clearance, clarify with ATC.  

5. Is the SID cancelled when the aircraft is cleared direct to a fix along the SID?

No, issuing a CLEARED DIRECT clearance to a waypoint on the SID means the aircraft will leave the SID temporarily, and resume own navigation on the SID at the cleared waypoint. While the restrictions of the bypassed waypoints are cancelled, all other remaining restrictions on the SID are still applicable.

Please note that if the aircraft was cleared direct to a waypoint not on the SID, the aircraft is taken off the SID and is now in a situation similar to that of being vectored off the procedure by ATC.

6. When the aircraft is cleared direct to a point on a SID/STAR, who becomes responsible for terrain clearance?

When an aircraft is issued a CLEARED DIRECT clearance, ATC becomes responsible for ensuring that the prescribed obstacle clearance exists until the aircraft reaches the point as cleared.

Flight crews should remain mindful of minimum safe altitudes, obstacles, and subsequent restrictions on the SID/STAR.

7. If the controller cancelled restrictions at a waypoint(s) (e.g. speed and/or level) on the SID/STAR, does that mean I can maintain any level or speed?

The aircraft should continue to climb/descend to maintain the cleared level as instructed. Any cancellation of level restriction(s) does not change your obligation to meet the cleared level, it only affects how the aircraft may adjusts it's vertical profile to meet the clearance.

When cancelling the speed restrictions on a SID/STAR, the speed restrictions associated with various classes of airspace (Annex 11, Appendix 4) remain valid, as would any other imposed restrictions not associated with the procedure.

Flight crews should be mindful of minimum safe altitudes, obstacles, and subsequent restrictions, even as ATC cancels the upcoming restriction. If there's a likelihood that you are unable to comply with the foreseen restrictions, please advise ATC.

8. When taken off a SID/STAR, should I expect to subsequently rejoin the procedure?

PANS-ATM 6.5.2.4.5 requires the controller to notify the flight crew if it is expected that the aircraft will be subsequently instructed to rejoin the SID/STAR. If unsure of ATC intent for the remaining portion of your departure or approach, please seek clarification.

If given prior notice of the expectation to rejoin the SID/STAR, and the waypoint to join, please advise ATC if you are unable (e.g. due to weather) to rejoin at the expected waypoint. ATC will be able to provide you with an alternative routing, which allow for better traffic and flight management.

If prior notification was not stated,  ATC should include the SID/STAR designator when issuing the clearance to rejoin a procedure. If unsure, please confirm with ATC.