Narrative:

We were out of 10000 and cleared to 17000' on a heading of 030 degrees. ATC asked if we saw traffic at 9 O'clock and 7 mi. My reply was no. ATC said the traffic (medium large transport) was heading 090 degrees and climbing to 17000'. My second scan of the direction I saw lights of an aircraft coming at an intersecting angle. I asked what his altitude was and the reply either from ATC or the aircraft was 19000' climbing. Our altitude at the time was 12300'. We were closing at a rapid rate. I told the copilot (PF) to stop the climb. We held 12300' and I told ATC we had stopped the climb. Within seconds the medium large transport flew overhead. It is difficult to judge distance, but we assumed 1000' or more. Had we not stopped our climb there is very little doubt that we would have hit. I asked the controller why he gave us both a climb. His answer was that he had asked medium large transport if he saw widebody transport and receiving a yes answer gave him a visibility climb. I asked for clearance to continue our climb and it was given. I told the controller that he was wrong to give that kind of clearance, because you cannot judge depth at night. ATC apologized and said he learned something. At about 50 degrees west I talked to medium large transport on 131.8. He thought that we were at 11000' and holding because, when he said that he did see widebody transport and asked what altitude widebody transport was at, the answer was 11000'. The controller failed to tell him that we were also climbing.

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Original NASA ASRS Text

Title: ARTCC RADAR CTLR ISSUED A VISUAL CLIMB TO AN ACFT WHICH PASSED OVER THE TOP OF ANOTHER ACFT.

Narrative: WE WERE OUT OF 10000 AND CLRED TO 17000' ON A HDG OF 030 DEGS. ATC ASKED IF WE SAW TFC AT 9 O'CLOCK AND 7 MI. MY REPLY WAS NO. ATC SAID THE TFC (MLG) WAS HDG 090 DEGS AND CLBING TO 17000'. MY SECOND SCAN OF THE DIRECTION I SAW LIGHTS OF AN ACFT COMING AT AN INTERSECTING ANGLE. I ASKED WHAT HIS ALT WAS AND THE REPLY EITHER FROM ATC OR THE ACFT WAS 19000' CLBING. OUR ALT AT THE TIME WAS 12300'. WE WERE CLOSING AT A RAPID RATE. I TOLD THE COPLT (PF) TO STOP THE CLB. WE HELD 12300' AND I TOLD ATC WE HAD STOPPED THE CLB. WITHIN SECS THE MLG FLEW OVERHEAD. IT IS DIFFICULT TO JUDGE DISTANCE, BUT WE ASSUMED 1000' OR MORE. HAD WE NOT STOPPED OUR CLB THERE IS VERY LITTLE DOUBT THAT WE WOULD HAVE HIT. I ASKED THE CTLR WHY HE GAVE US BOTH A CLB. HIS ANSWER WAS THAT HE HAD ASKED MLG IF HE SAW WDB AND RECEIVING A YES ANSWER GAVE HIM A VIS CLB. I ASKED FOR CLRNC TO CONTINUE OUR CLB AND IT WAS GIVEN. I TOLD THE CTLR THAT HE WAS WRONG TO GIVE THAT KIND OF CLRNC, BECAUSE YOU CANNOT JUDGE DEPTH AT NIGHT. ATC APOLOGIZED AND SAID HE LEARNED SOMETHING. AT ABOUT 50 DEGS W I TALKED TO MLG ON 131.8. HE THOUGHT THAT WE WERE AT 11000' AND HOLDING BECAUSE, WHEN HE SAID THAT HE DID SEE WDB AND ASKED WHAT ALT WDB WAS AT, THE ANSWER WAS 11000'. THE CTLR FAILED TO TELL HIM THAT WE WERE ALSO CLBING.

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.