Narrative:

At 10000 ft on the rokit STAR into iah, WX was on the arrival (towering cumulonimbus) 18000 ft down to 3000 ft. We got several 'cleared to deviate as necessary' from approach controllers because of the WX. Until frequency 120.05 controller told us to turn to a 180 degree heading. We told him about the multiple cumulonimbus and a 180 degree heading would put us right into the biggest cumulonimbus. He said 'I'm not asking, I'm telling you to fly 180 degree heading.' the captain told me too he's going to use his captain emergency authority/authorized and to tell the controller that. The frequency was busy and we couldn't get a word in for this statement. The controller stated he had to turn an airplane because of us. The WX was a fast moving, rain shower cumulonimbus all around iah area.

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Original NASA ASRS Text

Title: B737 CREW WAS FORCED TO USE CAPT'S EMER AUTH TO AVOID A TSTM ENCOUNTER.

Narrative: AT 10000 FT ON THE ROKIT STAR INTO IAH, WX WAS ON THE ARR (TOWERING CUMULONIMBUS) 18000 FT DOWN TO 3000 FT. WE GOT SEVERAL 'CLRED TO DEVIATE AS NECESSARY' FROM APCH CTLRS BECAUSE OF THE WX. UNTIL FREQ 120.05 CTLR TOLD US TO TURN TO A 180 DEG HDG. WE TOLD HIM ABOUT THE MULTIPLE CUMULONIMBUS AND A 180 DEG HDG WOULD PUT US RIGHT INTO THE BIGGEST CUMULONIMBUS. HE SAID 'I'M NOT ASKING, I'M TELLING YOU TO FLY 180 DEG HDG.' THE CAPT TOLD ME TOO HE'S GOING TO USE HIS CAPT EMER AUTH AND TO TELL THE CTLR THAT. THE FREQ WAS BUSY AND WE COULDN'T GET A WORD IN FOR THIS STATEMENT. THE CTLR STATED HE HAD TO TURN AN AIRPLANE BECAUSE OF US. THE WX WAS A FAST MOVING, RAIN SHOWER CUMULONIMBUS ALL AROUND IAH AREA.

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.