Date: 201301
Local time of day: 0601-1200
Location: DEN.Airport, CO
Flight conditions: VMC
Aircraft: A319
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Descent
Airspace: Class B DEN
ATC / advisory: TRACON D01
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Confusion; Situational Awareness; Communication Breakdown
Second reporter function: Pilot Not Flying; First Officer
Anomaly: ATC Issue All Types; Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Clearance
Detector: Person Air Traffic Control; Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued Advisory / Alert; Flight Crew Requested ATC Assistance / Clarification
Contributing factors: Human Factors; Chart Or Publication; Procedure
Primary problem: Ambiguous

Narrative: We were cleared to descend via the JAGGR RNAV STAR; landing south; so we put 9;000 FT in the altitude window. As we got closer to the airport they vectored us off the arrival for a downwind for Runway 7; specifically to turn five degrees left for Runway 7. This put us on a 295 heading. We were not given a revised altitude to descend too.  As we were descending through 12;500 FT the Controller asked us what altitude we were going to. We replied 9;000 FT because that is what we were cleared to descend to [prior to be vectored off] the arrival. The Controller; however; thought he had given us 13;000 FT. He then cleared us to descend to 11;000 FT and we continued to the airport and landed without farther incident.When getting vectored off an RNAV arrival always confirm the cleared altitude with ATC.


Second narrative: ...the Captain contacted Denver Approach and the Supervisor said that he had not heard anything about it and not to worry about it. He also added that if we are not given an amended altitude after being broken off that RNAV arrival; then we should request one. I disagree with Denver Approach Supervisor's remarks. There is no reason for us to have to play guessing games [as to the controller's intentions]. Upon our initial contact I specifically informed the Controller of our route; altitude passing; and altitude to which we were descending; utilizing the term 'VIA.' I have thus informed the Controller as to what we are [and will be] doing. If the controller decides he/she wants to amend a portion of the clearance; he/she may do so; however; if the amendment is specific to course/heading; it only amends our track. All previous clearances in all other aspects of flight remain the same until amended. I also want to clarify that there are instances where pilots are supposed to query when controllers have not issued clearances when they are supposed to -for example: short final and not cleared to land yet; no EFC upon issuance of entry in a holding pattern; etc. In our scenario there was no reason to query since clearances in all aspects of flight have already been received and complied with.


Synopsis: Confusion reigned as to their cleared altitude when the flight crew of an A319 was vectored off the JAGGR RNAV STAR to DEN in order to track South of the airport to land to the East.