Flight Crew Air Transport Pilot (ATP)
Confusion; Situational Awareness; Communication Breakdown
ATC Issue All Types
Air Traffic Control Issued New Clearance; Air Traffic Control Issued Advisory / Alert
Procedure; Human Factors
We were cleared to descend via the BOSSS RNAV STAR by DEN ARTCC enroute to DEN. Crew executed 'Descend Via' and aircraft did a good job of managing the descent; meeting all altitude and speed constraints all the way down. Upon initial contact with Approach Control over QUAIL at 17;000 FT Controller stated; 'Air Carrier X you are way too low; did the Center give you something else?' Both pilots (panicked) double checked the chart to verify and confirm altitude constraints at QUAIL. The aircraft was exactly where it was supposed to be with respect to charted altitude and lateral position for the BOSSS1. Controller issued a radar vector without an altitude to maintain other than the published STAR final altitude; crew queried her and she later assigned 13;000 FT.Later Controller advised we had done nothing wrong but; 'the Center should have known we were landing north and should not have cleared you for the BOSSS. We didn't know what was going on; we just opened up here.'We continued to a visual approach to Runway 35L without incidentThis is not the first time I have witnessed this type of confusion between DEN TRACON and DEN Center. Either the TRACON has not informed the center that the aircraft has been launched via radar vector rather than RNAV SID or the center assigns a STAR that is inconsistent with airfield direction. I have had the first Center Controller ask if we are on a heading and then apologize stating that Departure Control didn't tell him we were being radar vectored and not on RNAV. It seems like the two don't have a mechanism to know what the previous entity has assigned the aircraft. The Center Controller that assigned the arrival (which we were filed for) should have known that it was inconsistent with north landings and re-cleared us for the appropriate arrival. RNAV procedures while efficient and sleek from the ATC perspective pose significant threats and risks to the aircrews in the form of potential for pilot deviations and errors which affect safety. They should not be further complicated with threats generated by inefficiencies from within ATC. Better coordination and synergy MUST be undertaken by ATC to mitigate these threats and increase the margin of safety when operating these complex and demanding SIDS and STARS.
The Captain of an A320 expressed concern about the latest in a string of apparent miscommunications between DEN Center and DEN TRACON with respect to landing direction and the inappropriate STAR by which they had been cleared to descend by Center which then came as a big surprise to TRACON.