Date: 201405
Local time of day: 1201-1800
Location: DAL.Airport, TX
Flight conditions: VMC
Light: Daylight
Aircraft: Hawker Horizon (Raytheon)
Operator: Fractional
Operating under: Part 91
Flight plan: IFR
Flight phase: Initial Approach
Airspace: Class B DFW
ATC / advisory: TRACON D10
Aircraft component: FMS/FMC
Component problem: Design
Reporter organization: Air Carrier
Reporter function: Pilot Flying; First Officer
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Confusion; Distraction; Workload; Troubleshooting
Anomaly: ATC Issue All Types; Aircraft Equipment Problem Less Severe; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Flight Crew Took Evasive Action; Flight Crew Became Reoriented; Flight Crew Requested ATC Assistance / Clarification
Contributing factors: Aircraft; Procedure
Primary problem: Procedure

Narrative: On the Glen Rose 9 Arrival to DAL; at 7;000 FT; with Regional Approach Control; FMS had been configured for the JEN9 Arrival with [Runway] 13L as runway for approach. Approximately 2 miles before crossing FUZ (Ranger VOR); Regional Approach decided to award us ILS Runway 13R at DAL. The PIC; pilot not flying; loaded that approach into the FMS. When that was done; the FMS dropped the arrival and restarted it from JEN VOR way behind us; which began the approach transition (even though there were no official runway transitions published; they all went to the same final fix on the arrival). This was not expected by us. At the same time we crossed FUZ (Ranger VOR) and the FMS defaulted to ROLL mode instead of making the intended turn to the final fix leading to the approach which is HURBS Intersection. As we noticed it; ATC contacted us and said 'Air Carrier X; it appears you missed the turn at Ranger; turn right heading 110.' We informed him that we had because of the runway change he issued. He sounded annoyed. We were not 'visual' at that moment; so doing things visually with reference to the airport was not feasible. We were not established on any segment of the approach. No other actions were required. We continued on his heading per his instructions until he cleared us for the approach. Controllers are unaware that runway changes made at the last minute are dangerous as the workload can dramatically increase; but also because things like this arrival dropping out of the FMS at the exact wrong moment while over DFW at 7;000 FT can produce traffic issues as well. We were approximately 2 miles north of FUZ VOR when we became established on the heading that was newly assigned after our missed turn. The flight continued normally and uneventfully to the destination.All I can think of other than educating controllers as to the difficulties presented when they make last minute runway assignments/changes is that we could have asked for the runway assignment earlier; but we had only checked on with this Final Controller moments before the event occurred. We had no idea that the arrival would so dramatically restart itself from JEN when loading just the approach. We could have waited and loaded the approach later or just continued and visually aligned the aircraft with the runway; but again; we had no idea the arrival would reset and drop the last fix when loading the approach.




Synopsis: An HS125 crew began flying the DAL JEN.JEN 9 arrival; Runway 13L assigned. When ATC assigned Runway 13R two miles prior to FUZ; the FMS was reprogrammed and in doing so the autopilot transitioned to ROLL; the FMS re-inserted the arrival at JEN 50 miles behind the aircraft and a track deviation resulted.