B757 Undifferentiated or Other Model
Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Instructor
Flight Crew Total 4100
ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Requested ATC Assistance / Clarification
Chart Or Publication; Procedure
This new STAR has a big design problem. The DYAMD 2 STAR altitudes conflict with the RNAV visual approaches which causes:- confusion- extra automation workload for pilots- extra radio communication for ATC & pilots- increased potential for automation errorsThe STAR has ARCHI at 7;000 and CEDES between 12;000 & 10;000But; the FMS Bridge Visual and Quiet Bridge visual have ARCHI at 8;000 (FMS bridge visual also has CEDES at 11;000)As a result when a flight crew tries to build the approach and arrival in the FMS; they have to connect the path and the altitudes are 50% wrong whichever the pilot chooses in the FMS.This leads to more workload for controllers and automatic tactical modification of published routes and it can lead to automation errors.The operational solution is to clear pilots to descend via the DYAMD 2 (with the ARTCC) and later (with approach) to modify the clearance to 'except after CEDES maintain 8;000.'The controller mentioned that they were going to 'fix' this with a NOTAM soon but that leads to more issues:1) NOTAMs that attempt to 'fix' RNAV procedure design problems are themselves a non-conformance factor because they are hard to read; find and remember; and2) A NOTAM does not fix the original problem of the chart design flawI am reading FAA Order 7100.41 Performance Based Navigation Implementation Process to try and figure out why and where in the process this design error was made and if it was intentional or unintentional. Both are bad.Also; the 'DYAMD' name is a poor choice in my opinion because it is hard to read and say. I think it is pronounce 'diamond' but it is difficult for me and I am a native English speaker. How would you pronounce that if you didn't speak English well and did not know that it was called 'diamond'?
A B757 pilot described the design error and conflict between the SFO DYAMD RNAV Arrival 7;000 foot ARCHI constraint below Class B and the FMS BRIDGE Visual and the QUIET BRIDGE Visual 8;000 foot ARCHI constraint.