Narrative:

During descent I left the frequency to make PA for approximately 1 min 30 seconds descending through FL200. Had received clearance to intercept msp 086 degree radial cross 30 DME east at 10000 ft. Returned to frequency and received frequency change from msp center passing 14000 ft aircraft descending 4000 FPM. Contacted msp approach out of 11000 ft for 10000 ft approximately 35 DME. Could see aircraft on TCASII display at edge but could not see any altitude displayed. Before approach replied could see traffic displayed 600 ft below us. Captain leveled aircraft at 10600 ft. TCASII then changed to a climb RA which we complied with and leveled at 11000 ft when TCASII RA ceased saw air carrier Y pass below us. Msp approach asked if center had asked us to maintain 11000 ft.

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Original NASA ASRS Text

Title: ACR X TCASII RA DSCNT TO WRONG ALT HAD LTSS FROM ACR Y. SYS ERROR.

Narrative: DURING DSCNT I LEFT THE FREQ TO MAKE PA FOR APPROX 1 MIN 30 SECONDS DSNDING THROUGH FL200. HAD RECEIVED CLRNC TO INTERCEPT MSP 086 DEG RADIAL CROSS 30 DME E AT 10000 FT. RETURNED TO FREQ AND RECEIVED FREQ CHANGE FROM MSP CTR PASSING 14000 FT ACFT DSNDING 4000 FPM. CONTACTED MSP APCH OUT OF 11000 FT FOR 10000 FT APPROX 35 DME. COULD SEE ACFT ON TCASII DISPLAY AT EDGE BUT COULD NOT SEE ANY ALT DISPLAYED. BEFORE APCH REPLIED COULD SEE TFC DISPLAYED 600 FT BELOW US. CAPT LEVELED ACFT AT 10600 FT. TCASII THEN CHANGED TO A CLB RA WHICH WE COMPLIED WITH AND LEVELED AT 11000 FT WHEN TCASII RA CEASED SAW ACR Y PASS BELOW US. MSP APCH ASKED IF CTR HAD ASKED US TO MAINTAIN 11000 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.