B737-700
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 184; Flight Crew Type 9000
Situational Awareness; Confusion
Other Unwanted situation
Air Traffic Control Issued New Clearance; Flight Crew Requested ATC Assistance / Clarification
Human Factors; Procedure; Chart Or Publication
There is an error in the AMYLU RNAV STAR into CHS. If you reference the arrival; this will be clearer. On the descent into CHS; the altitude restrictions on the BAMDE transition from AMYLU are 'at or above' until you actually talk to CHS Approach and they assign you a final and a runway. However; in our case today; if you get handed off late to Approach you can be on VPATH and then have them assign you an approach and; when you select the approach; be immediately 6;000 feet high. The problem is that the BAMDE altitude needs to be a hard altitude or a window; say 5;000 feet to 3;000 feet. As it is; either 3;001 feet or 10;999 feet satisfies the arrival programming. All other ending altitudes that I find on RNAV arrivals are hard altitudes. Even the other transitions on the AMYLU Arrival have hard altitudes as final altitudes; i.e. KREIS at 3;000 feet; WABLO at 3;000 feet; and KMBEE at 4;000 feet.Today we found ourselves in this position and had to ask for and execute a 360-degree turn to lose enough altitude to shoot the RNAV RNP Z to 21. In accordance with the procedure; Approach Control assigns the approach and runway and; until they do that; you have a discontinuity from the end of the arrival to the approach. It is this discontinuity that causes the FMC to not descend at the proper rate so as to be in a position to execute the approach.
A B737-700 Captain believes the crossing altitude depicted at BAMDE waypoint (at or above 3;000 feet); on the AMYLU RNAV STAR for arrivals to Runway 21 at CHS; is inappropriate and should be a hard altitude to prevent arriving aircraft from being too high to continue the approach.