Narrative:

Flight was to spokane. WX was good and not a factor. Flight was uneventful until on final approach to runway 21 at geg. We approached geg from the south, anticipating a visual approach to runway 21. On left base, approach control called out traffic ahead and to our left. The traffic was a kc-135 on approach to fairchild AFB. We called the traffic in sight and were then cleared for a visual approach to runway 21. As we started a turn to final, we were told to contact tower. After check-in with tower, we were cleared to land on runway 21. Very shortly after, tower called out traffic close-in and to our left. Within seconds of this traffic call by tower, we received a TCASII RA to climb. At this time, we were on approximately 5 mi final at 1500 ft AGL. While executing the RA avoidance maneuver, we visually acquired the traffic as we passed directly over it. We estimate we passed 400 ft above the traffic. Traffic appeared to be a C152 or C172. After the near midair collision, we asked tower for a 360 degree turn to repos for a normal approach. We subsequently landed without incident. After shutdown at the gate, I explained to the passenger what had happened. Supplemental information from acn 592914: suddenly, pop-up traffic on final straight ahead caused our TCASII to sound off an RA to climb. We visually acquired a cessna, southeast crossing final going northwest, at our altitude. If the captain hadn't complied with the RA to climb given by TCASII, I believe a midair collision would have been the outcome. We were so busy looking outside that I missed the actual number of ft that we cleared the southeast aircraft. I believe it was about 300-400 ft.

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Original NASA ASRS Text

Title: A B737-300 CREW AND A C152 OR C172 HAD AN NMAC IN GEG CLASS C AIRSPACE. THE ATCT LCL CTLR GAVE A LATE TA AND DID NOT GIVE CLRNCS TO SEPARATE THE ACFT.

Narrative: FLT WAS TO SPOKANE. WX WAS GOOD AND NOT A FACTOR. FLT WAS UNEVENTFUL UNTIL ON FINAL APCH TO RWY 21 AT GEG. WE APCHED GEG FROM THE S, ANTICIPATING A VISUAL APCH TO RWY 21. ON L BASE, APCH CTL CALLED OUT TFC AHEAD AND TO OUR L. THE TFC WAS A KC-135 ON APCH TO FAIRCHILD AFB. WE CALLED THE TFC IN SIGHT AND WERE THEN CLRED FOR A VISUAL APCH TO RWY 21. AS WE STARTED A TURN TO FINAL, WE WERE TOLD TO CONTACT TWR. AFTER CHK-IN WITH TWR, WE WERE CLRED TO LAND ON RWY 21. VERY SHORTLY AFTER, TWR CALLED OUT TFC CLOSE-IN AND TO OUR L. WITHIN SECONDS OF THIS TFC CALL BY TWR, WE RECEIVED A TCASII RA TO CLB. AT THIS TIME, WE WERE ON APPROX 5 MI FINAL AT 1500 FT AGL. WHILE EXECUTING THE RA AVOIDANCE MANEUVER, WE VISUALLY ACQUIRED THE TFC AS WE PASSED DIRECTLY OVER IT. WE ESTIMATE WE PASSED 400 FT ABOVE THE TFC. TFC APPEARED TO BE A C152 OR C172. AFTER THE NMAC, WE ASKED TWR FOR A 360 DEG TURN TO REPOS FOR A NORMAL APCH. WE SUBSEQUENTLY LANDED WITHOUT INCIDENT. AFTER SHUTDOWN AT THE GATE, I EXPLAINED TO THE PAX WHAT HAD HAPPENED. SUPPLEMENTAL INFO FROM ACN 592914: SUDDENLY, POP-UP TFC ON FINAL STRAIGHT AHEAD CAUSED OUR TCASII TO SOUND OFF AN RA TO CLB. WE VISUALLY ACQUIRED A CESSNA, SE XING FINAL GOING NW, AT OUR ALT. IF THE CAPT HADN'T COMPLIED WITH THE RA TO CLB GIVEN BY TCASII, I BELIEVE A MIDAIR COLLISION WOULD HAVE BEEN THE OUTCOME. WE WERE SO BUSY LOOKING OUTSIDE THAT I MISSED THE ACTUAL NUMBER OF FT THAT WE CLRED THE SE ACFT. I BELIEVE IT WAS ABOUT 300-400 FT.

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.