Narrative:

Flight from den to cpr received a call from ATC that reported a 'hiball' balloon at about our 12 O'clock position which was last reported at 15000' on the lar 114 degree right at about 5 DME. I asked if ATC had an accurate fix on the balloon and was it lighted. He checked with FSS who confirmed that said fix was the most recent but was a few mins old. Center stated that balloon was not lighted and was rising at 800 FPM. I thought of asking for vectors but as there was not accurate position of balloon, any direction might have provided a collision course. We continued direct to mbw as previously cleared. A few mins later ATC stated he believed we were well clear of balloon. I heard him tell another aircraft the balloon was climbing through FL250. During this 13 min period the balloon passed through our altitude of FL200 somewhere near our aircraft. The system failed to provide adequate safety for our flight. I am not looking to place blame but rather for answers of how this potential accident could have been prevented.

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Original NASA ASRS Text

Title: FLT CREW OF COMMUTER GIVEN LOCATION AND ALT OF WX BALLOON LATER CALCULATED IT MAY HAVE PASSED THROUGH THEIR ALT AND VERY CLOSE.

Narrative: FLT FROM DEN TO CPR RECEIVED A CALL FROM ATC THAT RPTED A 'HIBALL' BALLOON AT ABOUT OUR 12 O'CLOCK POS WHICH WAS LAST RPTED AT 15000' ON THE LAR 114 DEG R AT ABOUT 5 DME. I ASKED IF ATC HAD AN ACCURATE FIX ON THE BALLOON AND WAS IT LIGHTED. HE CHKED WITH FSS WHO CONFIRMED THAT SAID FIX WAS THE MOST RECENT BUT WAS A FEW MINS OLD. CTR STATED THAT BALLOON WAS NOT LIGHTED AND WAS RISING AT 800 FPM. I THOUGHT OF ASKING FOR VECTORS BUT AS THERE WAS NOT ACCURATE POS OF BALLOON, ANY DIRECTION MIGHT HAVE PROVIDED A COLLISION COURSE. WE CONTINUED DIRECT TO MBW AS PREVIOUSLY CLRED. A FEW MINS LATER ATC STATED HE BELIEVED WE WERE WELL CLR OF BALLOON. I HEARD HIM TELL ANOTHER ACFT THE BALLOON WAS CLBING THROUGH FL250. DURING THIS 13 MIN PERIOD THE BALLOON PASSED THROUGH OUR ALT OF FL200 SOMEWHERE NEAR OUR ACFT. THE SYSTEM FAILED TO PROVIDE ADEQUATE SAFETY FOR OUR FLT. I AM NOT LOOKING TO PLACE BLAME BUT RATHER FOR ANSWERS OF HOW THIS POTENTIAL ACCIDENT COULD HAVE BEEN PREVENTED.

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.