Narrative:

Flight on departure control given a heading of 120 degrees and climb from 10000 to 20000. We had the radar on 40 mi scale with TCASII displayed. TA sounded so radar was switched to 20 then 10 mi scale. Yellow target at about 5 mi. Then TCASII switched to 5 mi scale. Red target at 3 mi plus 400 ft. We were approaching 12000 ft. At about 12000 there was a scattered to broken cloud layer of puffy cumulus clouds. Copilot was flying I said level off below the clouds. TCASII sounded 'descend' as we started pushing over from the climb. I asked departure if they had traffic at 12 O'clock from us. No answer. Just above the bottom of the puffy clouds at about 1/2 mi nearly level with us (at 1230 position) is a red single engine aircraft. He sees us about the same time and tries to roll right then rolls left and pulls up hard. We were pushing over at about 310 KTS and missed him by about 100 ft. I told this to departure and he said 'he's VFR. I wasn't talking to him.' he was, however, mode C, because we had an altitude on TCASII. Because of our climbing attitude it took longer to descend. The red aircraft was not in VFR conditions. Departure control climbed us right through him.

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Original NASA ASRS Text

Title: AN MLG ACR HAD A TCASII NMAC JUST BELOW AN OVCST. BOTH ACFT TOOK EVASIVE ACTION. ATC DID NOT HAVE THE INTRUDER ACFT.

Narrative: FLT ON DEP CTL GIVEN A HDG OF 120 DEGS AND CLB FROM 10000 TO 20000. WE HAD THE RADAR ON 40 MI SCALE WITH TCASII DISPLAYED. TA SOUNDED SO RADAR WAS SWITCHED TO 20 THEN 10 MI SCALE. YELLOW TARGET AT ABOUT 5 MI. THEN TCASII SWITCHED TO 5 MI SCALE. RED TARGET AT 3 MI PLUS 400 FT. WE WERE APCHING 12000 FT. AT ABOUT 12000 THERE WAS A SCATTERED TO BROKEN CLOUD LAYER OF PUFFY CUMULUS CLOUDS. COPLT WAS FLYING I SAID LEVEL OFF BELOW THE CLOUDS. TCASII SOUNDED 'DSND' AS WE STARTED PUSHING OVER FROM THE CLB. I ASKED DEP IF THEY HAD TFC AT 12 O'CLOCK FROM US. NO ANSWER. JUST ABOVE THE BOTTOM OF THE PUFFY CLOUDS AT ABOUT 1/2 MI NEARLY LEVEL WITH US (AT 1230 POS) IS A RED SINGLE ENG ACFT. HE SEES US ABOUT THE SAME TIME AND TRIES TO ROLL R THEN ROLLS L AND PULLS UP HARD. WE WERE PUSHING OVER AT ABOUT 310 KTS AND MISSED HIM BY ABOUT 100 FT. I TOLD THIS TO DEP AND HE SAID 'HE'S VFR. I WASN'T TALKING TO HIM.' HE WAS, HOWEVER, MODE C, BECAUSE WE HAD AN ALT ON TCASII. BECAUSE OF OUR CLBING ATTITUDE IT TOOK LONGER TO DSND. THE RED ACFT WAS NOT IN VFR CONDITIONS. DEP CTL CLBED US RIGHT THROUGH HIM.

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.