Regional Jet 900 (CRJ900)
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Became Reoriented; Flight Crew FLC Overrode Automation
Aircraft
I have recently discovered something that may be an issue in the CRJ-900 when flying between CLT-ZZZ(possibly to ZZZ1 as well). Today we were flying the usual route (BARMY3.NUTZE) and we were given a crossing restriction of FL230 at NUTZE. We were cruising at FL250 when I put the FL230 restriction into the FMS at NUTZE. We armed the VNAV in anticipation of the descent; but the FMS VNAV information showed that a climb was necessary to meet our crossing restriction. This made absolutely no sense at all; so obviously we intervened and made the restriction manually using VS mode. This is not the first time that this has happened to me on this routing. The first time I figured it was a fluke; but now that it has happened again it made me think otherwise. After passing NUTZE; the VNAV worked normally for further crossing restrictions.After consulting the FMS manual for the CRJ7/900; I discovered that the FMS assigned the NUTZE waypoint as a CLIMB waypoint since NUTZE is the last fix on the SID. All SID waypoints are initially assigned to be CLIMB waypoints. However; the FMS manual also says that the pilot can re-assign a waypoint to be a DESCENT waypoint by manually entering the crossing restriction (as we did). There seems to be an issue here with the FMS not allowing the pilot to override the CLIMB on this particular route/crossing. I would suggest looking into a possible software issue with this particular routing on the FMS. It could possibly lead to an altitude deviation if the unsuspecting flight crew does not catch it before they reach NUTZE. Even if this turns out to be how the FMS software is supposed to work; I would suggest a communication to the pilot group to warn that this may happen under certain circumstances.
CRJ900 Captain reported the FMC showed a climb vice a descent due to the designation of a climb waypoint on the SID even though the crew programmed a lower altitude.