Narrative:

All area sectors were combined and traffic was being worked on 2 radar scopes. During the relief briefing, the previous controller stated that he had turned air carrier X 5 degree left to go behind some traffic. This put the aircraft on a track to join the bonneville one arrival into pdx and I was not aware the STAR had not been issued. Air carrier X had been cleared to 140 and I reclred him to 100 in order to meet the LOA with pdx. As air carrier X descended through 134 I realized he had flown through the pdx 079 radial which he would have had to intercept to fly the STAR. I issued a clearance to 130 and a right turn direct btg VOR as the aircraft was about to enter an area of high terrain around mt hood. The pilot's reply was blocked by another aircraft. Air carrier X then stated his clearance was to 100. I replied negative and again issued 130 (which by now he had descended below) and a right turn in an effort to turn air carrier X away from the mountain peak. I also informed the pilot it appeared he'd flown through the arrival and asked if he had mt hood in sight. The pilot continued to descend and stated that he had been issued a heading. Again, I issued a right turn direct btg and a climb. The aircraft finally began his turn and climb and was handed off to pdx approach. Air carrier X came within 3 NM of the peak (11329 MSL) and descended below 110 before complying with instructions to turn and climb. A miscom between 2 controllers contributed to the initial development of the situation. Air carrier X had not been issued the STAR as shown on the flight plan. Due to computer processing of preferential arrival routes, in some cases the flight plan shows the STAR has been issued when in fact it has not. I assumed the pilot had been told to rejoin the STAR as would have been standard procedure had it been initially issued. I believe the situation developed into an imminent one due to lack of response on the part of the pilot. Air carrier X continued to descend and was slow in turning while the pilot questioned why his clearance was being changed. This arrival route needs to be changed. Although the route is flight checked down to 100, there is no room for error due to the proximity of high terrain. There have been numerous instances of aircraft flying through the intercept radial placing them head-on into mt hood. Until now, the dangerous situations have been avoided.

Related reports:

Google
 

Original NASA ASRS Text

Title: CTLR DESCENDED ACR X BELOW MVA. OPERATIONAL ERROR.

Narrative: ALL AREA SECTORS WERE COMBINED AND TFC WAS BEING WORKED ON 2 RADAR SCOPES. DURING THE RELIEF BRIEFING, THE PREVIOUS CTLR STATED THAT HE HAD TURNED ACR X 5 DEG LEFT TO GO BEHIND SOME TFC. THIS PUT THE ACFT ON A TRACK TO JOIN THE BONNEVILLE ONE ARR INTO PDX AND I WAS NOT AWARE THE STAR HAD NOT BEEN ISSUED. ACR X HAD BEEN CLRED TO 140 AND I RECLRED HIM TO 100 IN ORDER TO MEET THE LOA WITH PDX. AS ACR X DESCENDED THROUGH 134 I REALIZED HE HAD FLOWN THROUGH THE PDX 079 RADIAL WHICH HE WOULD HAVE HAD TO INTERCEPT TO FLY THE STAR. I ISSUED A CLRNC TO 130 AND A RIGHT TURN DIRECT BTG VOR AS THE ACFT WAS ABOUT TO ENTER AN AREA OF HIGH TERRAIN AROUND MT HOOD. THE PLT'S REPLY WAS BLOCKED BY ANOTHER ACFT. ACR X THEN STATED HIS CLRNC WAS TO 100. I REPLIED NEGATIVE AND AGAIN ISSUED 130 (WHICH BY NOW HE HAD DESCENDED BELOW) AND A RIGHT TURN IN AN EFFORT TO TURN ACR X AWAY FROM THE MOUNTAIN PEAK. I ALSO INFORMED THE PLT IT APPEARED HE'D FLOWN THROUGH THE ARR AND ASKED IF HE HAD MT HOOD IN SIGHT. THE PLT CONTINUED TO DSND AND STATED THAT HE HAD BEEN ISSUED A HDG. AGAIN, I ISSUED A RIGHT TURN DIRECT BTG AND A CLIMB. THE ACFT FINALLY BEGAN HIS TURN AND CLIMB AND WAS HANDED OFF TO PDX APCH. ACR X CAME WITHIN 3 NM OF THE PEAK (11329 MSL) AND DESCENDED BELOW 110 BEFORE COMPLYING WITH INSTRUCTIONS TO TURN AND CLIMB. A MISCOM BETWEEN 2 CTLRS CONTRIBUTED TO THE INITIAL DEVELOPMENT OF THE SITUATION. ACR X HAD NOT BEEN ISSUED THE STAR AS SHOWN ON THE FLT PLAN. DUE TO COMPUTER PROCESSING OF PREFERENTIAL ARR ROUTES, IN SOME CASES THE FLT PLAN SHOWS THE STAR HAS BEEN ISSUED WHEN IN FACT IT HAS NOT. I ASSUMED THE PLT HAD BEEN TOLD TO REJOIN THE STAR AS WOULD HAVE BEEN STANDARD PROC HAD IT BEEN INITIALLY ISSUED. I BELIEVE THE SITUATION DEVELOPED INTO AN IMMINENT ONE DUE TO LACK OF RESPONSE ON THE PART OF THE PLT. ACR X CONTINUED TO DSND AND WAS SLOW IN TURNING WHILE THE PLT QUESTIONED WHY HIS CLRNC WAS BEING CHANGED. THIS ARR ROUTE NEEDS TO BE CHANGED. ALTHOUGH THE ROUTE IS FLT CHECKED DOWN TO 100, THERE IS NO ROOM FOR ERROR DUE TO THE PROX OF HIGH TERRAIN. THERE HAVE BEEN NUMEROUS INSTANCES OF ACFT FLYING THROUGH THE INTERCEPT RADIAL PLACING THEM HEAD-ON INTO MT HOOD. UNTIL NOW, THE DANGEROUS SITUATIONS HAVE BEEN AVOIDED.

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.