Embraer Jet Undifferentiated or Other Model
Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Distraction; Troubleshooting
Aircraft Equipment Problem Less Severe; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Returned To Clearance
Aircraft; Human Factors
While on the DRLLR5 arrival and approaching DOMNO intersection; I was monitoring the FMS which took us just to the north of IAH then a left turn to proceed downwind for Runway 26L IAH on a 087 track to SKLER intersection. At DOMNO the autopilot did not make the turn and we received the Lateral mode off Crew Alerting System (CAS) message. I was the Pilot Monitoring but immediately turned the aircraft to make an intercept correction using heading mode to intercept the 087 track outbound. In the turn; ATC contacted us and gave us a heading to intercept then stated we missed the turn to downwind. I stated we had made the turn and was correcting but we would follow their vector to intercept. We then were told to go direct to ZOEEE and continue the arrival. We were asked to contact ATC on the ground. We noted no errors in the flight plan loaded in the FMS and the tracking on the arrival was in 'FMS NAV MODE' the whole time until the situation occurred.
I was Pilot Flying the DRLLR5 arrival into IAH for runway 26R in FMS/NAV mode. We had switched from our anticipated runway of 26L to the assigned runway of 26R. Both the Captain and I verified the points on the Jeppesen chart and the FMS. Upon approaching DOMNO we anticipated the aircraft to make the left turn to enter the downwind. This; however; did not occur and the EICAS presented a 'LATERAL MODE OFF'. The Captain and I selected heading mode and started a left turn. ATC then contacted us and assigned us a heading and told us we missed the turn to downwind and to expect a possible pilot deviation. The Captain called the number provided by ATC; who advised him the same issue had occurred the day prior with a different aircraft.
Embraer flight crew reported experiencing a lateral mode malfunction in the FMS and were consequently late turning as required by the STAR to IAH.