B737 Next Generation Undifferentiated
Flight Crew Air Transport Pilot (ATP)
Distraction; Workload
ATC Issue All Types; Deviation - Altitude Undershoot; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Became Reoriented; Flight Crew Took Evasive Action
Procedure
The SUUTR 2 has a known problem that is highlighted on the Weather Brief first page but that note should be more specific; and better yet; the STAR redesigned correctly. Currently the note says that 'several flights descending via...for unknown reasons' were high on arrival. How about the STAR is jacked up. We were on PATH and Speed at TRLOC (at or above FL290) we were at FL290. The VNAV PATH immediately defaulted to VSPD and we were 1200 ft high. The problem appears to be the 'at or below FL210 at FOOLZ' combined with SUUTR between FL260 and FL240. Those two restrictions don't work when combined with the prior at or above FL290. Stop filing and flying this arrival until it gets fixed or; failing that; accurately identify the problem to crews so they know when and where the STAR and VNAV and ATC's descend via are going to try and mess them up.
The reporter stated the B737NG FMC design is part of the issue because it does not identify the difficulty of meeting the descent constraints in advance. If a pilot were aware of this before the descent then initiate the descent immediately at TRLOC; the aircraft would probably be a little high but not by 1;000 ft or more. Local knowledge or an ATC alert would certainly provide a heads up. Occasionally ATC will issue a FL240 constraint providing another trap because if Altitude Intercept is not selected when cleared lower; the aircraft will again level off. In the end; this arrival should be redesigned to accommodate modern clear airframe aircraft.
B737NG Captain reported while flying the SMF SUUTR2 RNAV at FL290; the FMC indicated on path until the top of descent (TRLOC) at which point the FMC alerted they were 1;200 ft high on the descent. The FL210 FOOLZ crossing restriction is too low and close (23.4 NM) to meet the restriction.