Narrative:

While being vectored for the ILS 4R into newark; ATC issued a traffic advisory for an aircraft 500 ft below; opposite direction at approximately 10 to 11 o'clock. Both the captain and I began searching for the aircraft; I used the TCAS display and stated the aircraft was passing below us. I then spotted the aircraft and called it in sight. Shortly after the TCAS alerted 'monitor vertical speed.' I did not react because the aircraft was level and the TCAS commanded red for any descent on the vsi. At this point the captain reacted by pressing the tcs and initiating a descent and calling TCAS descent on the radio; thinking the aircraft was above us. I immediately responded by grabbing the control and stating no; no; no; the aircraft is below us. The captain then looked at the vsi and began a climb. We leveled off at 6;000 ft. I then inquired if approach knew we were now at 6;000 ft; and the captain verified that and told ATC that he was deviating for TCAS. Shortly thereafter we were instructed to descend and continued the approach and landing as normal. The threat was the traffic conflict in close proximity. The error was the captain and I not being on the same page as to the location of the traffic we were looking for. The undesired aircraft state was initiating a descent while the TCAS was alerting to not descend. I will be more assertive when searching for traffic to verify the location of traffic that I am looking for. When calling traffic in sight; using correct phraseology such as '10 o'clock low' will ensure that there is no confusion between crew members as to the location of the traffic in close proximity. I assumed the captain was seeing and hearing the same cues that I was. When a TCAS alert is triggered especially as the flying pilot; I should verbally respond what my action and intentions are. My lack of action likely lead to the captain feeling as though I was being complacent to the alert and urged him to take immediate action.

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Original NASA ASRS Text

Title: EMB145 First Officer arriving EWR is informed by ATC of opposite direction traffic 500 FT below. A TA is annunciated stating 'monitor vertical speed' with red indicated on the VSI for any descent. The First Officer maintains level flight but the Captain takes control and initiates a descent; which the First Officer quickly countermands. The Captain begins climbing and levels off at 6;000 FT.

Narrative: While being vectored for the ILS 4R into Newark; ATC issued a traffic advisory for an aircraft 500 FT below; opposite direction at approximately 10 to 11 o'clock. Both the Captain and I began searching for the aircraft; I used the TCAS display and stated the aircraft was passing below us. I then spotted the aircraft and called it in sight. Shortly after the TCAS alerted 'Monitor Vertical Speed.' I did not react because the aircraft was level and the TCAS commanded Red for any descent on the VSI. At this point the Captain reacted by pressing the TCS and initiating a descent and calling TCAS descent on the radio; thinking the aircraft was above us. I immediately responded by grabbing the control and stating No; No; No; the aircraft is below us. The Captain then looked at the VSI and began a climb. We leveled off at 6;000 FT. I then inquired if approach knew we were now at 6;000 FT; and the Captain verified that and told ATC that he was deviating for TCAS. Shortly thereafter we were instructed to descend and continued the approach and landing as normal. The threat was the traffic conflict in close proximity. The error was the Captain and I not being on the same page as to the location of the traffic we were looking for. The undesired aircraft state was initiating a descent while the TCAS was alerting to not descend. I will be more assertive when searching for traffic to verify the location of traffic that I am looking for. When calling traffic in sight; using correct phraseology such as '10 o'clock low' will ensure that there is no confusion between crew members as to the location of the traffic in close proximity. I assumed the Captain was seeing and hearing the same cues that I was. When a TCAS alert is triggered especially as the flying pilot; I should verbally respond what my action and intentions are. My lack of action likely lead to the Captain feeling as though I was being complacent to the alert and urged him to take immediate action.

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.