EMB ERJ 135 ER/LR
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Less Severe; Conflict Airborne Conflict; Deviation - Altitude Crossing Restriction Not Met; Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Clearance
Flight Crew Returned To Clearance; Flight Crew Overcame Equipment Problem; Flight Crew FLC complied w / Automation / Advisory
Aircraft; Human Factors
We were flying the ZZZZZ RNAV arrival into ZZZ inside of the ZZZZZ1 waypoint when ATC instructed us to descend via except cross ZZZZZ2 at 10;000 ft.; 2000 ft. higher than published. We informed ATC that if we comply with the assigned crossing restriction that we will have trouble making ZZZZZ at 6;000; [which was] only 8.2 miles from ZZZZZ2. ATC then replied; 'If you will be high on the arrival let me know.' We then decided to slow down the aircraft to prepare for making the crossing restrictions and recalculate our descent inside of ZZZZZ2 to advise ATC if we will be high or if we can comply with the ZZZZZ restriction.Once the Honeywell FMS reached waypoint passage over ZZZZZ2 and cycled to the next fix; we started down to make the next crossing restriction. Within a few seconds of starting our descent; we received a TCAS 'TRAFFIC' alert followed by a TCAS RA. I immediately disconnected the autopilot to comply with the RA and resolve the conflict. After the resolution advisory was resolved; [the Pilot Monitoring] noticed that the FMS had cycled to the next waypoint early and found that we were still a few tenths of a mile from ZZZZZ2 during the event. The assigned altitude at ZZZZZ2 was 10;000 ft.; we leveled off during the RA around 9;750 - 9;800 ft. There was no communication from ATC to us regarding the event. The rest of the arrival and approach was flown successfully and we landed safely.The Honeywell FMS cycled waypoints early; leading us to believe that we had reached waypoint passage. [I suggest] finding a solution to prevent the Honeywell FMS from making premature smart turns/waypoint passage cycles.
Operating [the] flight as SIC (Second in Command) and PM; we were assigned to descend via the ZZZZZ [arrival] but cross ZZZZZ2 at 10;000. We leveled off at 10;000 prior to the fix and set the next appropriate altitude. At about 2.5 miles prior to the fix; the Honeywell FMS prematurely sequenced to the next waypoint. We began an initial descent and quickly noticed the discrepancy in distance between current position and waypoint. [There was] an RA to 'monitor descent' annunciation. The Pilot Flying immediately climbed back to 10;000 and we waited until the correct DME was displayed. [The cause of the crossing altitude deviation was the] Honeywell FMS [working improperly]. I have noticed this problem in almost all company aircraft containing Honeywell FMS. The airplane will sequence to the next waypoint prior to the actual position. This can; and does lead to; altitude deviations and potential RAs and possibly worse. I would like to either see the problem itself fixed or the company to implement an SOP or training that covers this issue.
EMB135 flight crew reported a deviation from assigned altitude caused by the FMS during autopilot mode led to a TCAS RA during approach.