Narrative:

Our aircraft departed aff sbound for k1v6. Shortly after departure, we contacted cos approach. We leveled off at 8500 ft MSL, and proceeded on course for the west side of restr airspace R2601A/B. Shortly after leveling off we noticed another C172 slightly to the southeast of us. We kept aircraft in sight. It turned west and cut in front of us. Cos approach notified us of traffic 1 mi and 12 O'clock position. We notified approach that we had the traffic in sight. The aircraft proceeded wbound and leveled off at the same altitude. It then climbed slightly and began a left turn. As it completed 180 degrees of the turn it was coming right at us. It began to dive and we began to climb and I notified approach control that we were climbing to 9000 ft MSL to avoid traffic. Cos approach approved and we remained clear of the traffic.

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Original NASA ASRS Text

Title: 2 C172-S SEE AND AVOID EACH OTHER DURING A LAST MIN EVASIVE ACTION CLB DSCNT 9 MI W OF COS, CO.

Narrative: OUR ACFT DEPARTED AFF SBOUND FOR K1V6. SHORTLY AFTER DEP, WE CONTACTED COS APCH. WE LEVELED OFF AT 8500 FT MSL, AND PROCEEDED ON COURSE FOR THE W SIDE OF RESTR AIRSPACE R2601A/B. SHORTLY AFTER LEVELING OFF WE NOTICED ANOTHER C172 SLIGHTLY TO THE SE OF US. WE KEPT ACFT IN SIGHT. IT TURNED W AND CUT IN FRONT OF US. COS APCH NOTIFIED US OF TFC 1 MI AND 12 O'CLOCK POS. WE NOTIFIED APCH THAT WE HAD THE TFC IN SIGHT. THE ACFT PROCEEDED WBOUND AND LEVELED OFF AT THE SAME ALT. IT THEN CLBED SLIGHTLY AND BEGAN A L TURN. AS IT COMPLETED 180 DEGS OF THE TURN IT WAS COMING RIGHT AT US. IT BEGAN TO DIVE AND WE BEGAN TO CLB AND I NOTIFIED APCH CTL THAT WE WERE CLBING TO 9000 FT MSL TO AVOID TFC. COS APCH APPROVED AND WE REMAINED CLR OF THE TFC.

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.