Narrative:

While being radar vectored nne of den for sequencing for ILS approach to den, had to take evasive action to avoid on-coming aircraft, seemingly at same altitude and on collision course. This necessitated deviating from assigned radar vectoring altitude until it was confirmed that aircraft on collision course had turned away. Pilot advised den approach of aircraft at 11 O'clock, closing less than 1 mi away, about same altitude. Den approach didn't response in any manner. Other aircraft was still closing quickly. Pilot initiated evasive descent. At about 7600' den approach radioed to maintain 8000'. Pilot didn't response immediately, keeping in visibility contact with collision aircraft. Other aircraft finally began to turn away and I began climb back to 8000' from 7600'. All of this maneuvering took place in VFR conditions, luckily.

Google
 

Original NASA ASRS Text

Title: WHILE APCHING ARPT, ACFT CAME IN CLOSE PROX TO ANOTHER ACFT, NECESSITATING A TURN AND DESCEND TO AVOID ACFT.

Narrative: WHILE BEING RADAR VECTORED NNE OF DEN FOR SEQUENCING FOR ILS APCH TO DEN, HAD TO TAKE EVASIVE ACTION TO AVOID ON-COMING ACFT, SEEMINGLY AT SAME ALT AND ON COLLISION COURSE. THIS NECESSITATED DEVIATING FROM ASSIGNED RADAR VECTORING ALT UNTIL IT WAS CONFIRMED THAT ACFT ON COLLISION COURSE HAD TURNED AWAY. PLT ADVISED DEN APCH OF ACFT AT 11 O'CLOCK, CLOSING LESS THAN 1 MI AWAY, ABOUT SAME ALT. DEN APCH DIDN'T RESPONSE IN ANY MANNER. OTHER ACFT WAS STILL CLOSING QUICKLY. PLT INITIATED EVASIVE DSCNT. AT ABOUT 7600' DEN APCH RADIOED TO MAINTAIN 8000'. PLT DIDN'T RESPONSE IMMEDIATELY, KEEPING IN VIS CONTACT WITH COLLISION ACFT. OTHER ACFT FINALLY BEGAN TO TURN AWAY AND I BEGAN CLB BACK TO 8000' FROM 7600'. ALL OF THIS MANEUVERING TOOK PLACE IN VFR CONDITIONS, LUCKILY.

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.