Narrative:

[I] cleared dtw - pisnt intersection - waterloo 4 arrival into toronto. In cruise at FL190 between pistn intersection and waterloo on the waterloo 263 radial. First officer was flying and fully briefed the arrival with crossing restrictions and speeds. ATC cleared us to descend to 11;000 ft. We were not given any 'descend via' instructions. We took this as a routine descent clearance and began a descent from FL190 to 11;000 at a normal rate of descent (probably around 1;500 FPM). 11;000 is not a published altitude anywhere on the waterloo arrival into toronto. ATC later contacted us and said 'don't worry about it now' and pointed out a requirement to cross waterloo between 14;000 and 16;000 ft. We were later given a descent to 8;000. On the way to 8;000; the ATC controller told us to stop the descent at 8;000 due to departing traffic climbing to 7;000. The next published altitude on the chart was 6;000; but we had not been given a 'descend via' clearance or an altitude below 8;000. I firmly believe ATC was confused or mistaken as to whether we had been given a 'descend via' clearance; we had not. It appears that the arrival controllers at cyyz were expecting a 'descend via' - but we were never cleared that way. Cause; the threat was an altitude deviation; but I don't believe we had an altitude deviation. We complied with all clearances. I believe the controller made a mistake and didn't give us the clearance that the later controllers were expecting. Suggestions; I am concerned over the confusion this has caused. We were not given a 'descend via' clearance. The first officer and I were concerned that we now must query ATC on any new altitude to see if they really want us to descend to that altitude. Mistrust of routine ATC clearances greatly increases pilot workload. I think the controller made a mistake on his clearance.

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Original NASA ASRS Text

Title: Air Carrier on descent to Toronto was questioned by ATC with regard to crossing altitudes; the flight crew expressing concern reference the phrase 'descend VIA' and it's application/use in this event.

Narrative: [I] cleared DTW - PISNT Intersection - Waterloo 4 Arrival into Toronto. In cruise at FL190 between PISTN Intersection and Waterloo on the Waterloo 263 radial. First Officer was flying and fully briefed the arrival with crossing restrictions and speeds. ATC cleared us to descend to 11;000 FT. We were NOT given any 'descend via' instructions. We took this as a routine descent clearance and began a descent from FL190 to 11;000 at a normal rate of descent (probably around 1;500 FPM). 11;000 is NOT a published altitude anywhere on the Waterloo arrival into Toronto. ATC later contacted us and said 'don't worry about it now' and pointed out a requirement to cross Waterloo between 14;000 and 16;000 FT. We were later given a descent to 8;000. On the way to 8;000; the ATC Controller told us to stop the descent at 8;000 due to departing traffic climbing to 7;000. The next published altitude on the chart was 6;000; but we had not been given a 'descend via' clearance or an altitude below 8;000. I firmly believe ATC was confused or mistaken as to whether we had been given a 'descend via' clearance; we had NOT. It appears that the Arrival controllers at CYYZ were expecting a 'descend via' - but we were never cleared that way. Cause; the threat was an altitude deviation; but I don't believe we had an altitude deviation. We complied with all clearances. I believe the Controller made a mistake and didn't give us the clearance that the later controllers were expecting. Suggestions; I am concerned over the confusion this has caused. We were NOT given a 'descend via' clearance. The First Officer and I were concerned that we now must query ATC on ANY new altitude to see if they really want us to descend to that altitude. Mistrust of routine ATC clearances greatly increases pilot workload. I think the Controller made a mistake on his clearance.

Data retrieved from NASA's ASRS site as of July 2013 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.