Date: 201302
Local time of day: 1201-1800
Location: PCT.TRACON, VA
Flight conditions: VMC
Light: Daylight
Aircraft: Regional Jet 200 ER/LR (CRJ200)
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Flight phase: Descent
Airspace: Class B IAD
ATC / advisory: TRACON PCT
Aircraft component: FMS/FMC
Component problem: Design
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Reporter qualification: Flight Crew Commercial
Human factors: Confusion; Human-Machine Interface
Anomaly: ATC Issue All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control; Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented; Flight Crew Overcame Equipment Problem; Flight Crew Requested ATC Assistance / Clarification
Contributing factors: Chart Or Publication; Aircraft; Human Factors; Procedure
Primary problem: Human Factors

Narrative: While descending on the GIBBZ ONE RNAV ARRIVAL into IAD; we were planning on an approach to 19C; but when we had checked on to Potomac Approach; we were told to expect 19R. I continued the descent on the arrival while asking the PM to set up the new approach and brief it. He did; and we verified the new legs for the approach as well as verifying that the picture on the MFD made sense. We continued on the arrival but; after checking on with Potomac Final Approach; they told us to now expect Runway 19C. I had the PM make the change back to Runway 19C. We again verified the legs; verified the MFD made sense; and even made sure the first page of the legs page looked correct. After that we executed the [modified route] and continued. After GIBBZ; I noted that the autopilot didn't do a very good job of making the turn (1/4 dot deviation); and we started looking at the problem. At that point the PM noticed there was a discontinuity after SUNYJ [that had been hidden on page two of the legs page] and quickly worked to close it. By the time we had the course back in correctly; we were just passing over SUNYJ as we started our turn; thus performing as if it were a flyover fix as opposed to a flyby fix. We immediately informed ATC we were having a Nav issue and they issued us a vector; [and] then informed us that; due to the malfunction; the spacing for 19C was not going to work; and to again expect the visual for 19R. When the PM loaded the new approach again; the same problem happened. We noticed the problem; and made it correct before executing the FMS. The flight then continued; and landed; without incident.I'm really not sure what we could have done better to prevent this. We were especially careful to ensure we had the correct runway with the correct fixes; and also that the [Map display] made sense. The discontinuity was hidden because it stopped the arrival at SUNYJ; but started it again back at GIBBZ. This made it look ok to us; and there were enough fixes between where we made the change and where the discontinuity was to hide it. From now on; I know that during a runway change; I will not only verify the approach on the Map; but will also verify all the remaining legs. It will only take a few moments; and will help prevent future deviations.




Synopsis: When ATC changed their arrival runway inbound to IAD in the vicinity of GIBBZ; the flight crew of a CRJ-900 failed to note a route discontinuity on the second page of their route subsequent to reprogramming. A modest track deviation and another runway reassignment ensued.