Narrative:

On climb out from centennial, departure runway 10, observed at 1 O'clock position which appeared southeast-bound at approximately my altitude. Pointed traffic out to student and continued climbing. Runways 35L&right were in use, but runway 10/28 was also in use for departures and arrs. When I continued scanning to the right, aircraft observed at my 3 O'clock position on a collision course. Took evasive action by reducing power to idle and entering steep dive. No traffic was pointed out by the tower as there was heavy traffic and frequency congestion. I assume aircraft was on a left base for runway 28. Other aircraft never deviated from flight path and did not seem to notice the imminent collision.

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Original NASA ASRS Text

Title: INSTRUCTOR AND STUDENT DEPART RWY 10 AT APA AND ENCOUNTER A C172 ON A COLLISION COURSE APPARENTLY ON BASE LEG FOR RWY 28.

Narrative: ON CLBOUT FROM CENTENNIAL, DEP RWY 10, OBSERVED AT 1 O'CLOCK POS WHICH APPEARED SE-BOUND AT APPROX MY ALT. POINTED TFC OUT TO STUDENT AND CONTINUED CLBING. RWYS 35L&R WERE IN USE, BUT RWY 10/28 WAS ALSO IN USE FOR DEPS AND ARRS. WHEN I CONTINUED SCANNING TO THE R, ACFT OBSERVED AT MY 3 O'CLOCK POS ON A COLLISION COURSE. TOOK EVASIVE ACTION BY REDUCING PWR TO IDLE AND ENTERING STEEP DIVE. NO TFC WAS POINTED OUT BY THE TWR AS THERE WAS HVY TFC AND FREQ CONGESTION. I ASSUME ACFT WAS ON A L BASE FOR RWY 28. OTHER ACFT NEVER DEVIATED FROM FLT PATH AND DID NOT SEEM TO NOTICE THE IMMINENT COLLISION.

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.