Narrative:

On the bonham 2 arrival a strong thunderstorm cell approximately 30 mi across was located at mamee intersection. A larger but weaker thunderstorm cluster was at and east of bonham. After passing tul we requested direct birle as this would keep us well clear of the strong cell. The controller told us he had our request. At 80 mi from mamee we explained we would have to deviate to the south to avoid WX over mamee. Again, the controller told us he had our request. The rule of thumb for thunderstorm cell avoidance I have been taught both as a military aviator and at air carrier is to keep 20 mi between you and the storm to avoid turbulence and/or hail damage. We were rapidly approaching the point that a turn to the south would have us pass 20-30 mi away from the cell. Again at 60 mi from the cell we informed the controller a deviation to avoid WX was necessary. Again, the controller told us he had our request. At that point I had enough and told the controller directly that this was not a request and that we were deviating to a 185 degree heading to avoid WX. I turned to 185 degrees and reported steady on that heading. The controller said not to deviate, that he would quote 'not let me go into the storm.' he gave no reason for denying the deviation. The radio is no place for an argument so I returned to the original FMC course. I then briefed my first officer that if we got any more guff at 40 mi from the storm I was going to declare an emergency and turn to avoid the storm. At 40 mi we were turned over to the next controller. I forcefully explained the last controller had refused to allow us to deviate and that I was immediately turning to avoid WX. The new controller sounded surprised and told me to deviate as necessary, direct bonham when able. I had to turn all the way to a 215 degree heading and passed 18 mi from the storm. I understand that I did not have a picture of the traffic, but my TCASII showed nothing to prevent my deviation. The controller never gave any reason for delaying my deviation. When I said in plain terms that I was not requesting to deviate but was actually deviating I thought he would get the message that the situation was serious and that the only thing I had left was an emergency declaration. I do not understand why he failed to allow me to maneuver and why he failed to keep me informed so I could make a plan based on information rather than trying to respond to a lack of information in a potentially dangerous situation. In my 24 yrs of flying this is the first time I have been completely denied a WX deviation request.

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Original NASA ASRS Text

Title: FLC OF A FK10 TURNED OFF COURSE WITHOUT CLRNC FOR APCHING TSTM CELLS DURING HIGH ALT CRUISE ON A STAR ARR. ATC INTERVENED AND HAD THEM RETURN TO THEIR ORIGINAL ASSIGNED STAR ARR RTE.

Narrative: ON THE BONHAM 2 ARR A STRONG TSTM CELL APPROX 30 MI ACROSS WAS LOCATED AT MAMEE INTXN. A LARGER BUT WEAKER TSTM CLUSTER WAS AT AND E OF BONHAM. AFTER PASSING TUL WE REQUESTED DIRECT BIRLE AS THIS WOULD KEEP US WELL CLR OF THE STRONG CELL. THE CTLR TOLD US HE HAD OUR REQUEST. AT 80 MI FROM MAMEE WE EXPLAINED WE WOULD HAVE TO DEVIATE TO THE S TO AVOID WX OVER MAMEE. AGAIN, THE CTLR TOLD US HE HAD OUR REQUEST. THE RULE OF THUMB FOR TSTM CELL AVOIDANCE I HAVE BEEN TAUGHT BOTH AS A MIL AVIATOR AND AT ACR IS TO KEEP 20 MI BTWN YOU AND THE STORM TO AVOID TURB AND/OR HAIL DAMAGE. WE WERE RAPIDLY APCHING THE POINT THAT A TURN TO THE S WOULD HAVE US PASS 20-30 MI AWAY FROM THE CELL. AGAIN AT 60 MI FROM THE CELL WE INFORMED THE CTLR A DEV TO AVOID WX WAS NECESSARY. AGAIN, THE CTLR TOLD US HE HAD OUR REQUEST. AT THAT POINT I HAD ENOUGH AND TOLD THE CTLR DIRECTLY THAT THIS WAS NOT A REQUEST AND THAT WE WERE DEVIATING TO A 185 DEG HDG TO AVOID WX. I TURNED TO 185 DEGS AND RPTED STEADY ON THAT HEADING. THE CTLR SAID NOT TO DEVIATE, THAT HE WOULD QUOTE 'NOT LET ME GO INTO THE STORM.' HE GAVE NO REASON FOR DENYING THE DEV. THE RADIO IS NO PLACE FOR AN ARGUMENT SO I RETURNED TO THE ORIGINAL FMC COURSE. I THEN BRIEFED MY FO THAT IF WE GOT ANY MORE GUFF AT 40 MI FROM THE STORM I WAS GOING TO DECLARE AN EMER AND TURN TO AVOID THE STORM. AT 40 MI WE WERE TURNED OVER TO THE NEXT CTLR. I FORCEFULLY EXPLAINED THE LAST CTLR HAD REFUSED TO ALLOW US TO DEVIATE AND THAT I WAS IMMEDIATELY TURNING TO AVOID WX. THE NEW CTLR SOUNDED SURPRISED AND TOLD ME TO DEVIATE AS NECESSARY, DIRECT BONHAM WHEN ABLE. I HAD TO TURN ALL THE WAY TO A 215 DEG HDG AND PASSED 18 MI FROM THE STORM. I UNDERSTAND THAT I DID NOT HAVE A PICTURE OF THE TFC, BUT MY TCASII SHOWED NOTHING TO PREVENT MY DEV. THE CTLR NEVER GAVE ANY REASON FOR DELAYING MY DEV. WHEN I SAID IN PLAIN TERMS THAT I WAS NOT REQUESTING TO DEVIATE BUT WAS ACTUALLY DEVIATING I THOUGHT HE WOULD GET THE MESSAGE THAT THE SIT WAS SERIOUS AND THAT THE ONLY THING I HAD LEFT WAS AN EMER DECLARATION. I DO NOT UNDERSTAND WHY HE FAILED TO ALLOW ME TO MANEUVER AND WHY HE FAILED TO KEEP ME INFORMED SO I COULD MAKE A PLAN BASED ON INFO RATHER THAN TRYING TO RESPOND TO A LACK OF INFO IN A POTENTIALLY DANGEROUS SIT. IN MY 24 YRS OF FLYING THIS IS THE FIRST TIME I HAVE BEEN COMPLETELY DENIED A WX DEV REQUEST.

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.