Date: 201308
Local time of day: 0601-1200
Location: OMA.Airport, NE
Flight conditions: VMC
Light: Daylight
Aircraft: Citationjet (C525/C526) - CJ I / II / III / IV
Operator: Corporate
Operating under: Part 91
Flight plan: IFR
Mission: Passenger
Flight phase: Descent
Airspace: Class E OMA
ATC / advisory: TRACON OMA
Reporter organization: Corporate
Reporter function: Pilot Flying; Captain
Reporter qualification: Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Instructor
Human factors: Situational Awareness; Human-Machine Interface; Time Pressure
Anomaly: Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Air Traffic Control Provided Assistance; Flight Crew Returned To Clearance; Flight Crew Became Reoriented
Contributing factors: Procedure; Human Factors; Aircraft
Primary problem: Human Factors

Narrative: I was flying the MARWI1 arrival [STJ Transition] into Omaha for a landing on [Runway] 14L; coupled to the autopilot in NAV mode. After crossing MARWI; we tracked 300 to SWAAB. After SWAAB; the arrival requires flying a heading of 320 [and] then expect radar vectors to final approach course. However; I mistakenly followed the guidance of my GNS-500 in NAV mode which continued past SWAAB for approximately 7 miles direct to the airport (OMA) until ATC called with a heading of 320; vectors to the final approach course. I repeated back the instruction; changed the autopilot mode controller to heading mode; and turned to a heading of 320. Seconds later; a different Controller advised me of my mistake. The flight was continued and concluded with no further incident. The time of the incident was a higher workload situation. We were preparing for the landing; checking for traffic ahead and the pilot not flying was contacting the FBO for our arrival. We discussed having the field in sight from 30-35 miles away and announced it to Omaha Approach. We had briefed the arrival but as time elapsed; we forgot about flying the heading after SWAAB and simply followed the GPS.I believe that there are several contributing factors to this mistake. First; the Garmin GNS-500 has no way of navigating a heading. Unless the procedure involves 'tracking' a heading; it will navigate directly to the airport. Secondly; the inconsistency of arrival procedures from airport to airport. We routinely fly [an arrival into another airport that calls for a] 'track' of 346. Our GPS can comply with this routing whereas it can not fly a heading. If all arrivals would incorporate 'tracking' headings instead of 'flying' headings; they would be consistent and wouldn't require the changing of the autopilot mode control. Thirdly; while we weren't below 10;000 FT; we allowed ourselves to be distracted with other tasks (calling the FBO) while in a high workload environment.While I can't do anything to change the way my autopilot works or the way the arrivals are built; I can change how and when we call the FBO and handle other non-critical tasks. I will discuss with the flight crew a new procedure for handling those tasks while further out from our destination (50 miles).




Synopsis: C525 Captain reported deviating from an arrival into OMA in part because his FMS cannot fly headings; only tracks.