Flight Crew Air Transport Pilot (ATP)
Confusion; Human-Machine Interface; Situational Awareness
Deviation - Altitude Crossing Restriction Not Met; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
General None Reported / Taken
Company Policy; Human Factors; Aircraft; Procedure
The Perf Init (FMS page) was routinely programmed with a Vmo/Mmo/3.0 descent; the standard configuration. Upon descent we were cleared to cross WYNDE at 10;000 [FT]. I verified the correct TOD with the information in the FMS progress page as well as the VN (Vertical Navigation) Data page; and began an early descent. Throughout; the descent I monitored our progress on the VN Data page which consistently showed around -2;000 FT; as well as the PFD V-path indicator (showing below the required path for WYNDE). These (incorrect) indications continued all the way until we crossed WYNDE at 12;000 [FT]; which is 2;000 FT above the requirement. By the time the crew realized both indications; the VN Data page and the PFD VPI; were false; there was insufficient time to make complete corrections; and we crossed at 12;000 [FT]. With increased use of OPDs and other heavily FMS dependent descents; I must seriously question the reliability of our equipment. The FMS is supposed to help manage the flight; it is now becoming a threat. FMSs have lied to the crews before. If this continues; flight crews will be forced to advise ATC that they are unable RNAV descents; because of FMS unreliability.
Despite having insured proper FMS programming and monitoring available vertical path guidance; an E-145 flight crew failed to comply with the 10;000 FT crossing restriction at WYNDE waypoint while flying the WYNDE RNAV STAR to ORD.