Date: 201903
Local time of day: 0001-0600
Location: BFI.Airport, WA
Flight conditions: IMC
Light: Daylight
Aircraft: Small Transport; Low Wing; 2 Turbojet Eng
Operator: Fractional
Operating under: Part 91
Flight plan: IFR
Flight phase: Descent
Airspace: Class B SEA
ATC / advisory: TRACON S46
Reporter organization: Fractional
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Human factors: Confusion; Situational Awareness
Second reporter function: First Officer; Pilot Not Flying
Anomaly: Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Requested ATC Assistance / Clarification
Contributing factors: Chart Or Publication; Human Factors
Primary problem: Chart Or Publication

Narrative: Upon arrival to BFI we were flying the JAWBN SIX ARRIVAL without incident until we reached ALKIA fix on the arrival. At that point it diverges in three different directions depending on the runway in use at BFI; or traffic going to McChord Field. The way I had my chart set on my screen; it looked to me that the landing south heading of 070 off ALKIA fix was correct for the arrival; so I didn't catch it right away. (I had the chart zoomed in so I didn't clearly see the south courses on the screen.) When the airplane started to turn to the 070 degree course it looked correct to me. In addition to that; we were task saturated in the descent looking for traffic and setting the airplane up to land on a 20 minute flight. We discussed the arrival runway briefly but the FMS (Flight Management System) defaulted to landing south and we didn't catch it in time. The Approach Controller turned us to a heading; and advised of the landing runway heading requirements for the arrival at ALKIA; and we proceeded and landed without further incident.The arrival procedures that I have seen lately are being used for so many different airports and landing directions that it is becoming difficult to see these types of errors before they happen. Instead of having one fix where three different things can happen; have a different name for each procedure that is runway specific and leads you to a different fix; or onto the approach. Such as JAWBN SOUTH; JAWBN NORTH; etc. Denver is becoming more like this as well; if we are task saturated it can be confusing to get a common split point like ALKIA and know for sure what is supposed to happen when you get there. Even if you have briefed the approach; it can cause confusion. In the future; I know that I am going to have to see the multi divergent courses piled on one fix as a threat and focus on them in the brief to ensure what should happen at the fix is clear before we get there and things are busy.


Second narrative: When I programmed the FMS before departure I entered the JAWBN6 arrival with the default Runway 14L because the winds at BFI were calm. I had the intent of changing that later when I received the ATIS and arrival runway. We were descending; but not descend via and with no speed restrictions but following the arrival points. ATC called traffic for us and I put up the traffic screen instead of the arrival procedure. We got to ALKIA and turned left to 070 degrees (MANSEQ for Runway 14L). ATC queried; 'Are you guys turning left to 70 degrees?' We said we were and he gave us a new heading and informed us we should have flown 163 degrees for the transition to landing north and assigned us a new heading. Short; busy flight; missed the change to correct runway. Adding factors are the interruptions during FMS (Flight Management System) programming when line personnel show up with ice; papers; catering and interrupt your flow.ATC could have different arrival names for landing north and south etc. The POLAR2 for north; and SUNBM4 for south. But ultimately the responsibility was our and we made a human error on the short busy flight.


Synopsis: Corporate jet flight crew reported a heading deviation while on the JAWBN SIX ARRIVAL to BFI.