Falcon 900
Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Instructor; Flight Crew Instrument
Flight Crew Last 90 Days 35; Flight Crew Total 13500; Flight Crew Type 794
Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Flight Crew Became Reoriented; Flight Crew Returned To Clearance
Aircraft; Human Factors
We were being vectored north of Dallas for our arrival into DAL. We had originally been cleared on the JFRYE2 but had been vectored off by Fort Worth Center. When we were approximately 20-25NM northeast of the GREGS intersection we were cleared directly to GREGS and cleared to descend via the JFRYE2 arrival. Due to our position and the location of the subsequent fix; MNKEE; the FMS calculated a smart turn north and east of GREGS. As we flew closer to GREGS; we discovered that the smart turn would be greater than 4NM when abeam GREGS. The controller asked us to verify the last clearance; which we did; and we explained the situation. I used the heading mode to manually steer the aircraft closer to GREGS using the moving map display. The course to MNKEE was recaptured; and the rest of the arrival was flown without incident.This scenario is a known issue with the Honeywell Epic platform. The manufacturer has instructed operators to reset the LNAV Bank Factor from 7 to 15 to prevent FMS early smart turns. It appears that this setting resets to 7 after base software has been installed because 3 of the company aircraft I checked had 7 in the LNAV Bank Factor. This is not an item that is called out to be checked in the expanded POWER ON checks.
Falcon 900 Captain reported a track deviation occurred when the FMS commanded an early 'smart turn.'