Narrative:

At the time we were on the helns four arrival and had just crossed kratr intersection at 12000 ft, 300 KTS, when we were instructed by approach control to 'slow to 250 KTS, then descend to 7000 ft.' this was read back and we slowed, then descended as per the clearance. At approximately 7800 ft, we were advised that there was 'traffic below at 7000 ft and to maintain 8000 ft.' I immediately climbed back to 8000 ft. The pilot from aircraft Y flight at 7000 ft asked the controller what altitude we were cleared to and she read back 'I cleared aircraft Y to 10000 ft.' the response from aircraft Y was 'that was close.' we replied by saying that 'you cleared aircraft Y to 7000 ft.'

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Original NASA ASRS Text

Title: DC9 LNDG PDX EXPERIENCED NEAR MISS WITH ANOTHER ACFT.

Narrative: AT THE TIME WE WERE ON THE HELNS FOUR ARR AND HAD JUST CROSSED KRATR INTXN AT 12000 FT, 300 KTS, WHEN WE WERE INSTRUCTED BY APCH CTL TO 'SLOW TO 250 KTS, THEN DSND TO 7000 FT.' THIS WAS READ BACK AND WE SLOWED, THEN DSNDED AS PER THE CLRNC. AT APPROX 7800 FT, WE WERE ADVISED THAT THERE WAS 'TFC BELOW AT 7000 FT AND TO MAINTAIN 8000 FT.' I IMMEDIATELY CLBED BACK TO 8000 FT. THE PLT FROM ACFT Y FLT AT 7000 FT ASKED THE CTLR WHAT ALT WE WERE CLRED TO AND SHE READ BACK 'I CLRED ACFT Y TO 10000 FT.' THE RESPONSE FROM ACFT Y WAS 'THAT WAS CLOSE.' WE REPLIED BY SAYING THAT 'YOU CLRED ACFT Y TO 7000 FT.'

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.