Originally Posted by
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.
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.