Narrative:

While doing a 210 KTS; westerly climb off pdx 28R; traffic popped up on the TCAS just off the nose. It appeared within TA range and immediately we heard 'traffic; traffic' from the TCAS. ATC advised traffic off our nose at 7;000 ft. We had a high rate of climb already and were climbing through 6;500 ft. We had been given a turn to the right just prior and I increased the turn rate and tried to increase the climb rate to get above the traffic. At or about the same time we got an ATC traffic alert and a TCAS reduce vertical speed. It seems that the traffic I was trying to out climb was trying to out climb us. I lowered the nose and further increased the right bank. I'm not sure but the TCAS displayed recommend climb reduction didn't look anywhere near enough to avoid a collision so I lowered the nose even more and reduced the power. I had my flight director and autothrottles off prior to the incident so I was able to quickly react to the rapidly changing situation. My best recollection is that we came within 100 ft below the traffic and extremely close laterally. I never saw the plane other than on the TCAS. I do not believe the passengers noticed the incident as I adjusted flight path smoothly and the combination of a steep bank while lowering the nose canceled out the G force. I believe the maximum speed attained was 260 KTS for few seconds while in a descent. After the incident; ATC informed us he was not talking to the traffic. The first officer also noted that at some point the TCAS RA seemed to make a dramatic change to more closely reflect what I had already initiated.

Related reports:

Google
 

Original NASA ASRS Text

Title: An Air Carrier aircraft had a near miss with an unknown aircraft after departing PDX Runway 28R while climbing through 6;500 FT; headed westerly.

Narrative: While doing a 210 KTS; westerly climb off PDX 28R; traffic popped up on the TCAS just off the nose. It appeared within TA range and immediately we heard 'TRAFFIC; TRAFFIC' from the TCAS. ATC advised traffic off our nose at 7;000 FT. We had a high rate of climb already and were climbing through 6;500 FT. We had been given a turn to the right just prior and I increased the turn rate and tried to increase the climb rate to get above the traffic. At or about the same time we got an ATC Traffic Alert and a TCAS reduce vertical speed. It seems that the traffic I was trying to out climb was trying to out climb us. I lowered the nose and further increased the right bank. I'm not sure but the TCAS displayed recommend climb reduction didn't look anywhere near enough to avoid a collision so I lowered the nose even more and reduced the power. I had my flight director and autothrottles off prior to the incident so I was able to quickly react to the rapidly changing situation. My best recollection is that we came within 100 FT below the traffic and extremely close laterally. I never saw the plane other than on the TCAS. I do not believe the passengers noticed the incident as I adjusted flight path smoothly and the combination of a steep bank while lowering the nose canceled out the G force. I believe the maximum speed attained was 260 KTS for few seconds while in a descent. After the incident; ATC informed us he was not talking to the traffic. The First Officer also noted that at some point the TCAS RA seemed to make a dramatic change to more closely reflect what I had already initiated.

Data retrieved from NASA's ASRS site as of July 2013 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.