Narrative:

On descent into cho we were in contact with washington center. I (first officer pilot not flying) was making a PA announcement when center told us to descend and maintain FL200; and gave us a right turn 15 degrees for traffic. I did not hear these instructions; and when I came back on frequency I misinterpreted what the captain (ca) told me about the other traffic we were looking for. I thought we were 15 right for traffic that was climbing. We were in about a 2;700 FPM decent when un-expectedly I saw the traffic immediately off to our right and the traffic was heading right for us at about a 45 degree intercept angle.ATC vectored us directly toward the traffic we were supposed to be avoiding. I was unaware that he was level at FL190 and we were going to stop at FL200; so I told the captain we needed to stop the descent about the time we were leveling out. At that time we got a TCAS RA and he immediately dis-engaged the auto pilot and started a climb. In the process of doing this we went 300 feet below our assigned altitude of FL200. The root cause of this incident was poor communication by ATC; and my lack of understanding of what the other traffic was doing. I asked ATC why they vectored us into another aircraft and he explained to me what he meant to have happen; at which point I understood my mistake; and overall lack of understanding of what direction the other traffic was heading; our assigned altitude; and his assigned altitude.

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Original NASA ASRS Text

Title: A First Officer reports that he was off frequency when the Captain received a clearance to level at FL200 to avoid traffic at FL190. The crew then received a TCAS RA and complied with the procedure; but descended 300 feet below FL200.

Narrative: On descent into CHO we were in contact with Washington Center. I (First Officer pilot not flying) was making a PA announcement when center told us to descend and maintain FL200; and gave us a right turn 15 degrees for traffic. I did not hear these instructions; and when I came back on frequency I misinterpreted what the Captain (CA) told me about the other traffic we were looking for. I thought we were 15 right for traffic that was climbing. We were in about a 2;700 FPM decent when un-expectedly I saw the traffic immediately off to our right and the traffic was heading right for us at about a 45 degree intercept angle.ATC vectored us directly toward the traffic we were supposed to be avoiding. I was unaware that he was level at FL190 and we were going to stop at FL200; so I told the captain we needed to stop the descent about the time we were leveling out. At that time we got a TCAS RA and he immediately dis-engaged the auto pilot and started a climb. In the process of doing this we went 300 feet below our assigned altitude of FL200. The root cause of this incident was poor communication by ATC; and my lack of understanding of what the other traffic was doing. I asked ATC why they vectored us into another aircraft and he explained to me what he meant to have happen; at which point I understood my mistake; and overall lack of understanding of what direction the other traffic was heading; our assigned altitude; and his assigned altitude.

Data retrieved from NASA's ASRS site 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.