Narrative:

Approaching msp our instructions were departure fgt heading 050 degrees, then (after fgt was passed) we were told to head 070 degrees, descended to 5000' and slow to 170 KTS. Radio communication was clear, semi-congested (estimate 6 aircraft on frequency). Aircraft Z was told to immediately speed up to 180 KTS, which was acknowledged. Our last acknowledged instructions included comment that vector would take us through localizer and to expect s-turns to OM. Widebody transport air carrier Y was visible to us approximately 18 mi east of msp and heading our way. Approach control gave a partially covered instruction, '(screech) turn left 280 degrees,' which was acknowledged by voice similar to aircraft Z. As we proceeded 070 degree heading air carrier Y got nearer at about same altitude. Since frequency was congested, we held off questioning clearance as we could see traffic. Air carrier Y asked approach why we (air carrier X) were in front of them. Reply was that we had been given turn to 280 degrees (and perhaps something else), acknowledged it and not done it, but that adequate radar sep was present. Rest of flight was routine. I called approach control after landing and was told they did get a computer alert after we had crossed in front of air carrier Y and sep was adequate. It appears that someone acknowledged a clearance meant for us west/O identifying himself. Common problem? You bet. Later call to approach said radar plot indicated less than 3 mi latitude sep.

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Original NASA ASRS Text

Title: LESS THAN STANDARD SEPARATION BETWEEN 2 ACR. OPERATIONAL ERROR.

Narrative: APCHING MSP OUR INSTRUCTIONS WERE DEP FGT HDG 050 DEGS, THEN (AFTER FGT WAS PASSED) WE WERE TOLD TO HEAD 070 DEGS, DESCENDED TO 5000' AND SLOW TO 170 KTS. RADIO COM WAS CLR, SEMI-CONGESTED (ESTIMATE 6 ACFT ON FREQ). ACFT Z WAS TOLD TO IMMEDIATELY SPEED UP TO 180 KTS, WHICH WAS ACKNOWLEDGED. OUR LAST ACKNOWLEDGED INSTRUCTIONS INCLUDED COMMENT THAT VECTOR WOULD TAKE US THROUGH LOC AND TO EXPECT S-TURNS TO OM. WDB ACR Y WAS VISIBLE TO US APPROX 18 MI E OF MSP AND HEADING OUR WAY. APCH CTL GAVE A PARTIALLY COVERED INSTRUCTION, '(SCREECH) TURN LEFT 280 DEGS,' WHICH WAS ACKNOWLEDGED BY VOICE SIMILAR TO ACFT Z. AS WE PROCEEDED 070 DEG HDG ACR Y GOT NEARER AT ABOUT SAME ALT. SINCE FREQ WAS CONGESTED, WE HELD OFF QUESTIONING CLRNC AS WE COULD SEE TFC. ACR Y ASKED APCH WHY WE (ACR X) WERE IN FRONT OF THEM. REPLY WAS THAT WE HAD BEEN GIVEN TURN TO 280 DEGS (AND PERHAPS SOMETHING ELSE), ACKNOWLEDGED IT AND NOT DONE IT, BUT THAT ADEQUATE RADAR SEP WAS PRESENT. REST OF FLT WAS ROUTINE. I CALLED APCH CTL AFTER LNDG AND WAS TOLD THEY DID GET A COMPUTER ALERT AFTER WE HAD CROSSED IN FRONT OF ACR Y AND SEP WAS ADEQUATE. IT APPEARS THAT SOMEONE ACKNOWLEDGED A CLRNC MEANT FOR US W/O IDENTIFYING HIMSELF. COMMON PROB? YOU BET. LATER CALL TO APCH SAID RADAR PLOT INDICATED LESS THAN 3 MI LAT SEP.

Data retrieved from NASA's ASRS site as of August 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.