cantwin

If you are given an intersection to cross at 15,000', then during the descent ATC says "cross xyz fix at 8,000'" ... that fix being past the first fix (at 15,000'). Are you still supposed to cross the first fix at 15,000' and the next one at 8,000'? Or does the new crossing restriction automatically delete the old one?

Thanks.

DeadHead

This currently came up during a recent flight I had, so we looked into and checked it out with our chief pilot's office.

AIM 4-4-10
g. The guiding principle is that the last ATC clearance has precedence over the previous ATC clearance. When the route or altitude in a previously issued clearance is amended, the controller will restate applicable altitude restrictions. If altitude to maintain is changed or restated, whether prior to departure or while airborne, and previously issued altitude restrictions are omitted, those altitude restrictions are canceled, including departure procedures and STAR altitude restrictions.


As I understand it if ATC still wanted you to comply with an earlier restriction then they would restate the restriction in addition to the new altitude assignment.

In your example, if ATC wanted you to comply with both altitude restrictions the clearance would be;
"Cross abc at 15,000 then cross xyz at 8,000"
The new clearance would cancel out an earlier restriction.

Not sure how much flying you do out of the states but, Canada would not restate the clearance issued earlier, but would still expect you to comply.

cantwin

Seems about right... thank you!

Beaver Hunter

Keep in mind this does not apply world wide. But it certainly does in The US.

SeaRider

True. You have to be careful even in Canada. They will clear you to decend 6000' or whatever, but you must meet the crossing restrictions at fixes with altitudes between your current and cleared altitude. Those crazy Canucks always like to muddy the waters, eh?

iceman49

When in doubt, pick up the mic and ask

cougar

Publication of ATC Altitude Restrictions Notices to Airmen On Standard Instrument Departures
Publication of ATC Altitude Restrictions On Standard Instrument Departures
Purpose: To clarify and modify Aeronautical Information Manual (AIM), Paragraph 5?2?8 Instrument Departure Procedures (DP) ? Obstacle Departure Procedures (ODP) and Standard Instrument Departures (SID) guidance on Air Traffic Control (ATC) and procedure required altitude restrictions on Standard Instrument Departure (SID) procedures.
Background:
In early 2010, the FAA changed charting of ATC altitude restrictions on SIDs in response to ongoing industry concerns, first voiced in 1992, about ATC directed changes to published altitudes on SIDs. Those concerns include:
Pilot ability to discern the required climb gradient/ aircraft performance to comply with published crossing restrictions when ATC has issued an interim altitude lower than the published altitude or vectored an aircraft off of a procedure and then cleared the aircraft to re*join the procedure at a fix or waypoint with a published restriction.
Pilot ability to discern appropriate lost communications procedures when an aircraft is removed from the lateral/vertical path of a departure procedure.
Pilot ability to discern altitude restrictions that provide terrain obstruction clearance.
The charting specification change identified ATC procedural restrictions with an “(ATC)” annotation, e.g., 9000 (ATC). Altitude restrictions on the updated charts without an (ATC) annotation, e.g., 8000 are deemed procedure required restrictions which cannot be modified or lowered. The intent of the (ATC) annotation or absence thereof is to indicate to aircrew and ATC which restrictions are published to support obstacle clearance, airspace restrictions, navaid reception, or other reason(s) that mandated compliance. More importantly the annotation delineates for the pilot and controller which restrictions can be modified by ATC.
A limited number of the over 1,200 SIDs published have been updated to the revised (ATC) specification. However, the vast majority of procedures currently published still comply with the previous charting specification. In response to questions regarding the new specifications, the following guidance is provided. The FAA is also re*evaluating the (ATC) altitude charting specification through the Aeronautical Charting Forum.

Guidance:
The intent of this guidance is to expand upon that in the Aeronautical Information Manual (AIM), Paragraph 5?2?8 Instrument Departure Procedures (DP) ? Obstacle Departure Procedures (ODP) and Standard Instrument Departures (SID).

1. On procedures with a published crossing restriction at a fix or waypoint depicted with an (ATC) annotation, aircrew should verify that the altitude for the fix or waypoint programmed in the onboard navigation system is the (ATC) altitude. On procedures with a published crossing restriction at a fix or waypoint with no (ATC) annotation depicted, aircrew should verify that the altitude for the fix or waypoint programmed in the onboard navigation system is the charted altitude.

2. Pilots must comply with all charted altitudes unless explicitly amended/cancelled by ATC. Additionally, prior to or after takeoff, if an altitude restriction is issued by ATC, all previously issued altitude restrictions are cancelled including those published on a SID. Altitudes issued by ATC will assure IFR obstruction clearance. ATC is responsible for obstacle clearance to the point where the aircraft is established laterally and vertically on a segment of a published SID at or above the minimum depicted altitude for that segment altitude.

3. After an aircraft is established on a SID and subsequently vectored or cleared off of the SID, the SID is considered canceled. The controller may clear the aircraft to resume the SID or advise the aircraft to expect to resume SID at a subsequent fix or waypoint. However, in any case, the pilot should expect to rejoin the SID and plan accordingly.

4. ATC will not vector an aircraft off of an ODP until it is at or above the MVA/MIA. When an aircraft is vectored off of an ODP the ODP is canceled and cannot be resumed.

5. Examples of (ATC) annotation:
Example 1: The charted altitude of 7000 (ATC) at FITON is the altitude referenced in paragraph 1 (first sentence) and should be displayed in the onboard navigation system at FITON. The altitude of 4000 charted at FITON is the obstacle clearance/navigation reception altitude and is displayed for pilot reference.
Example 2: The charted altitude of 3000 at BEICH is the altitude referenced in paragraph 1 (second sentence) and should be displayed in the onboard navigation system at BEICH.