Narrative:

The B734 and the FK28 were being metered to seattle with 6 to 8 min delay's. The B734 was at 160 south of olm. The FK28 was southeast of olm at 170 on a delay vector. The FK28 was cleared direct olm, then the olm 2 arrival to sea. One min later, it was determined that the FK28 needed an additional delay. He was then given a 280 degree vector, shortly after he left 170 for 160. A loss of separation occurred 2 mi south of olm. The pilot indicated that when he was cleared direct olm, he was also cleared to 'dscnd via the olm arrival.' but the problem is that the arrival has a note 'maintain last assigned altitude until cleared to dscnd via the olm STAR.' this has been an ongoing problem with this STAR, with it's profile descent. A lot of times, the pilot confuses dscnd via'- for cleared for the olm arrival. Callback conversation with reporter revealed the following information: controller's principle concern is that the STAR has not reduced frequency congestion. It has reduced clearance phraseology. But with the many observed, incorrect pilot compliance actions, controllers have been required to engage in additional communication's to clarify the STAR's intent. Another complication with the STAR is that turboprop traffic utilized the same route structure, but at a lower altitude. When air carrier's are delayed vectored off,then back onto the STAR route, the controller frequently observes descent from the assigned altitude, the pilot thinking that clearance back onto the STAR in also a 'dscnd via' clearance when no such clearance has been issued. The controller had no specific suggestion for change or clarification of the STAR at this time, but was developing an editorial amendment suggestion soon.

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Original NASA ASRS Text

Title: ZSE CTLR CONCERNED WITH THE OLYMPIA STAR PROCS AND PLT INTERP OR QUESTIONS THAT HE RECEIVES DAILY.

Narrative: THE B734 AND THE FK28 WERE BEING METERED TO SEATTLE WITH 6 TO 8 MIN DELAY'S. THE B734 WAS AT 160 S OF OLM. THE FK28 WAS SE OF OLM AT 170 ON A DELAY VECTOR. THE FK28 WAS CLRED DIRECT OLM, THEN THE OLM 2 ARR TO SEA. ONE MIN LATER, IT WAS DETERMINED THAT THE FK28 NEEDED AN ADDITIONAL DELAY. HE WAS THEN GIVEN A 280 DEG VECTOR, SHORTLY AFTER HE LEFT 170 FOR 160. A LOSS OF SEPARATION OCCURRED 2 MI S OF OLM. THE PLT INDICATED THAT WHEN HE WAS CLRED DIRECT OLM, HE WAS ALSO CLRED TO 'DSCND VIA THE OLM ARR.' BUT THE PROB IS THAT THE ARR HAS A NOTE 'MAINTAIN LAST ASSIGNED ALT UNTIL CLRED TO DSCND VIA THE OLM STAR.' THIS HAS BEEN AN ONGOING PROB WITH THIS STAR, WITH IT'S PROFILE DSCNT. A LOT OF TIMES, THE PLT CONFUSES DSCND VIA'- FOR CLRED FOR THE OLM ARR. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: CTLR'S PRINCIPLE CONCERN IS THAT THE STAR HAS NOT REDUCED FREQ CONGESTION. IT HAS REDUCED CLRNC PHRASEOLOGY. BUT WITH THE MANY OBSERVED, INCORRECT PLT COMPLIANCE ACTIONS, CTLRS HAVE BEEN REQUIRED TO ENGAGE IN ADDITIONAL COM'S TO CLARIFY THE STAR'S INTENT. ANOTHER COMPLICATION WITH THE STAR IS THAT TURBOPROP TFC UTILIZED THE SAME RTE STRUCTURE, BUT AT A LOWER ALT. WHEN ACR'S ARE DELAYED VECTORED OFF,THEN BACK ONTO THE STAR RTE, THE CTLR FREQUENTLY OBSERVES DSCNT FROM THE ASSIGNED ALT, THE PLT THINKING THAT CLRNC BACK ONTO THE STAR IN ALSO A 'DSCND VIA' CLRNC WHEN NO SUCH CLRNC HAS BEEN ISSUED. THE CTLR HAD NO SPECIFIC SUGGESTION FOR CHANGE OR CLARIFICATION OF THE STAR AT THIS TIME, BUT WAS DEVELOPING AN EDITORIAL AMENDMENT SUGGESTION SOON.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.