FLC OF AN MLG UNDERSHOT DSCNT ALT DURING A STAR ARR CAUSING ATC TO INTERVENE AND TURN THEM OFF COURSE IN ORDER TO PROVIDE THE APPROPRIATE SEPARATION OF OPPOSITE DIRECTION TFC.

Narrative

AS FLT LEVELED OFF AT CRUISE ALT FL290; CAPT PROGRAMMED ARR ROUTING INTO FMC WHILE FO FLEW ACFT. FLT CROSSED STAR INTXN #1 AT FL240 AND WAS THEN CLRED TO FL230. ON THE ARR FLT ENCOUNTERED MODERATE CLR AIR TURB AT FL230 AND FO WENT OFF PRIMARY ATC RADIO FREQ TO MAKE PA TO PAX; WITH CAPT ASSUMING CTL OF ACFT AND CLRNC TO FL220; CROSS WHIGG INTXN AT 11000 FT. DSCNT TO FL220 WAS INITIATED AND ACFT LEVELED AT FL220; WITH ALT ALERTER SET AT 11000 FT. TURB AVOIDANCE BECAME PRIMARY FOCUS OF AIRCREW AND FMC COMPUTER WAS NOT UPDATED WITH 11000 FT ALT RESTR AT WHIGG (FMC DSCNT PROFILE WAS COMPUTED TO ARRIVE AT LAS FIELD ONLY). UPON COMPLETION OF PA; FO ASSUMED CTL OF ACFT AND CAPT LEFT PRIMARY ATC FREQ TO COORDINATE TURB ACTIONS WITH FLT ATTENDANTS AND PAX. FO FOLLOWED FMC-PROGRAMMED DSCNT PROFILE AND APPROX 5 MI FROM WHIGG INTXN CTLR ASKED IF FLT WOULD BE ABLE TO COMPLY WITH THE ASSOCIATED ALT RESTR. ACFT WAS NOT ABLE TO DSND TO MEET RESTR AND WAS VECTORED AWAY FROM ARR CORRIDOR AND INSTRUCTED TO MAINTAIN ALT FOR OPPOSITE DIRECTION TFC TO PASS BY. AIRCREW COMPLIED WITH REVISED INSTRUCTIONS AND WAS SUBSEQUENTLY RECLRED FOR ARR INTO LAS WITH NO FURTHER COMPLICATIONS. THIS SEEMS LIKE A HUMAN PERFORMANCE AND COM FAILURE BTWN THE PLTS FLYING WITH ASSUMPTION BY FO THAT BOTH ARR ROUTING AND ALT RESTRS WERE ENTERED INTO FMC WHEN THIS WAS NOT THE CASE. TURB ISSUES DISTRACTED AIRCREW FROM BACKING EACH OTHER UP.