Date: 201209
Local time of day: 1201-1800
Location: DCA.Airport, DC
Flight conditions: VMC
Light: Daylight
Aircraft: Regional Jet 200 ER/LR (CRJ200)
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Descent
Airspace: Class B DCA
ATC / advisory: TRACON PCT
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Time Pressure; Confusion; Communication Breakdown
Second reporter function: Captain; Pilot Not Flying
Anomaly: ATC Issue All Types; Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Clearance
Detector: Person Flight Crew; Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Flight Crew Returned To Clearance
Contributing factors: Human Factors; Procedure; Chart Or Publication
Primary problem: Procedure

Narrative: We were cleared to descend via the TRUPS1 arrival and the second Controller had cleared us to continue the arrival via Runway 19 transition. Prior to reaching FRDMM waypoint the Controller told us to depart FRDMM heading 120 which seemed excessive. The [crossing] restriction at FRDMM is 8;000 FT. The pilot not flying queried the Controller regarding the heading; but due to congestion he couldn't get a word in edgewise. Finally; the Controller issued new instructions to continue on the arrival. We were now at 8;000 FT and were past FRDMM [and were descending to comply with] the next crossing restriction of 6;000 FT [at STAND]. Shortly thereafter; the Controller issued another heading change; and took us off the arrival. Seconds prior; when [we were] on the arrival we had continued our descent. I asked the Captain to ask for clarification; at which point the Controller replied that we were told to 'continue on' the arrival and not to 'descend via' the arrival. We quickly returned to 8;000 FT and were cleared for the river visual shortly thereafter.The instructions were confusing at best. We were given a heading and; when we asked to confirm the heading; the response was changed to 'stay on the arrival.' If the Controller had said 'stay on the arrival maintain 8;000' the confusion would not have taken place.


Second narrative: [The Controller's] response was to descend to 8;000 FT and continue on the arrival. After crossing FRDMM we started to descend to 6;000 FT per the STAR and at the same time the Controller issued a heading change. I asked the First Officer if we should continue the descent since ATC just took us off the arrival and shortly after ATC asked us if we were still at 8;000 FT and I told him we were returning to 8;000 FT but thought we were still cleared to descend [as previously cleared] 'via' the arrival. He explained that our new instructions were to 'CONTINUE;' not to 'DESCEND VIA' the arrival.


Synopsis: Confusion reigned when the flight crew of a CRJ-200; cleared to 'descend via' the TRUPS RNAV STAR to DCA was given a questionable heading as they approached FRDMM; but were then re-cleared again to 'continue' the arrival. The next fix; STAND; had a crossing restriction of 210/6;000 and the crew was uncertain if they were required to comply with that restriction. When they were unable to get timely clarification and continued their descent; Approach advised they were 'not' cleared to descend below 8;000.