Narrative:

Level at FL370, we received TA on TCASII. Intruder was at 2 O'clock (on screen) at FL370. Several seconds later received 'climb-climb' RA. Climbed to FL37.5 and traffic intruder disappeared. Returned to assigned altitude. Never visually saw intruder. ATC seemed nonchalant and reported no aircraft at that altitude. This was a repeat airplane write-up (false alerts). Talking to other crews, and reading write-ups in other aircraft, false alerts are common near the colorado river due to military radar. If crews are taking evasive action for false targets, obviously there is a problem somewhere.

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Original NASA ASRS Text

Title: DEV FROM ASSIGNED ALT. DUE TO TCASII RA.

Narrative: LEVEL AT FL370, WE RECEIVED TA ON TCASII. INTRUDER WAS AT 2 O'CLOCK (ON SCREEN) AT FL370. SEVERAL SECONDS LATER RECEIVED 'CLB-CLB' RA. CLBED TO FL37.5 AND TFC INTRUDER DISAPPEARED. RETURNED TO ASSIGNED ALT. NEVER VISUALLY SAW INTRUDER. ATC SEEMED NONCHALANT AND RPTED NO ACFT AT THAT ALT. THIS WAS A REPEAT AIRPLANE WRITE-UP (FALSE ALERTS). TALKING TO OTHER CREWS, AND READING WRITE-UPS IN OTHER ACFT, FALSE ALERTS ARE COMMON NEAR THE COLORADO RIVER DUE TO MIL RADAR. IF CREWS ARE TAKING EVASIVE ACTION FOR FALSE TARGETS, OBVIOUSLY THERE IS A PROBLEM SOMEWHERE.

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.