Narrative:

During initial cruise flight; the WX radar displayed fail several times on the HSI. When tested; an additional weak right message was displayed. We advised dispatch who patched us through to maintenance. Maintenance instructed us to reset the WX radar circuit breaker which we did. The radar then worked for approximately 20 mins and then failed again. We decided not to fly the airplane to south america in that condition. Dispatch was advised of our decision and coordination a return to ZZZ. We obtained an ATC clearance back to ZZZ and explained to the flight attendants and the passenger the reason for our return to ZZZ. After consulting with dispatch and maintenance; we decided that it would be safe to make an overweight landing at ZZZ. The approach and landing were smooth and uneventful.

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Original NASA ASRS Text

Title: A B767-300 FLT CREW ENROUTE TO SOUTH AMERICA NOTICED A 'WX RADAR FAIL' EICAS MESSAGE AND DECIDED TO RETURN TO THEIR DEPARTURE AIRPORT FOR AN OVERWEIGHT LANDING.

Narrative: DURING INITIAL CRUISE FLT; THE WX RADAR DISPLAYED FAIL SEVERAL TIMES ON THE HSI. WHEN TESTED; AN ADDITIONAL WEAK R MESSAGE WAS DISPLAYED. WE ADVISED DISPATCH WHO PATCHED US THROUGH TO MAINT. MAINT INSTRUCTED US TO RESET THE WX RADAR CIRCUIT BREAKER WHICH WE DID. THE RADAR THEN WORKED FOR APPROX 20 MINS AND THEN FAILED AGAIN. WE DECIDED NOT TO FLY THE AIRPLANE TO SOUTH AMERICA IN THAT CONDITION. DISPATCH WAS ADVISED OF OUR DECISION AND COORD A RETURN TO ZZZ. WE OBTAINED AN ATC CLRNC BACK TO ZZZ AND EXPLAINED TO THE FLT ATTENDANTS AND THE PAX THE REASON FOR OUR RETURN TO ZZZ. AFTER CONSULTING WITH DISPATCH AND MAINT; WE DECIDED THAT IT WOULD BE SAFE TO MAKE AN OVERWT LNDG AT ZZZ. THE APCH AND LNDG WERE SMOOTH AND UNEVENTFUL.

Data retrieved from NASA's ASRS site as of May 2009 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.