Narrative:

We were attempting to fly phl to dca and a pwrful line of thunderstorms was causing us to deviation significantly from our flight planned route. Shortly after being switched to dca approach we were told to fly a 290 degree heading. After turning to this heading we determined that to continue would have us enter a line of severe WX. We told ATC of the situation and he gave us this ultimatum 'turn to 290 degrees or declare a WX emergency and you're on your own.' I told him I was not in an emergency but could not fly his heading and that we needed a southerly heading for approximately 20 mi. He insisted that I either turn to the 290 degree heading or declare a 'WX emergency.' I decided to divert to richmond, va. On the previous flight from dca-phl we did not observe WX that would cause us to delay our return trip. We had no access in phl to current WX/radar information. We got no warning of the severe WX from dispatchers or any others (ATC, other pilots). A cable tv hookup to the WX channel or any current radar 'picture' would have (possibly) prevented this situation from occurring. From previous encounters and our radar picture we knew to fly the requested 290 degree heading would have been extremely dangerous. The ATC's ultimatum of penetrate dangerous WX or declare a WX emergency and lose ATC services made a WX problem, worse.

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Original NASA ASRS Text

Title: COMMUTER PIC BEMOANS THE PROCS THAT DENY HIM WX DISPLAYS FOR TSTM ACTIVITY AND PROVIDES LIMITED ABILITY TO DEVIATE AROUND THE TSTMS WITH ATC'S BLESSINGS.

Narrative: WE WERE ATTEMPTING TO FLY PHL TO DCA AND A PWRFUL LINE OF TSTMS WAS CAUSING US TO DEV SIGNIFICANTLY FROM OUR FLT PLANNED RTE. SHORTLY AFTER BEING SWITCHED TO DCA APCH WE WERE TOLD TO FLY A 290 DEG HDG. AFTER TURNING TO THIS HDG WE DETERMINED THAT TO CONTINUE WOULD HAVE US ENTER A LINE OF SEVERE WX. WE TOLD ATC OF THE SIT AND HE GAVE US THIS ULTIMATUM 'TURN TO 290 DEGS OR DECLARE A WX EMER AND YOU'RE ON YOUR OWN.' I TOLD HIM I WAS NOT IN AN EMER BUT COULD NOT FLY HIS HDG AND THAT WE NEEDED A SOUTHERLY HDG FOR APPROX 20 MI. HE INSISTED THAT I EITHER TURN TO THE 290 DEG HDG OR DECLARE A 'WX EMER.' I DECIDED TO DIVERT TO RICHMOND, VA. ON THE PREVIOUS FLT FROM DCA-PHL WE DID NOT OBSERVE WX THAT WOULD CAUSE US TO DELAY OUR RETURN TRIP. WE HAD NO ACCESS IN PHL TO CURRENT WX/RADAR INFO. WE GOT NO WARNING OF THE SEVERE WX FROM DISPATCHERS OR ANY OTHERS (ATC, OTHER PLTS). A CABLE TV HOOKUP TO THE WX CHANNEL OR ANY CURRENT RADAR 'PICTURE' WOULD HAVE (POSSIBLY) PREVENTED THIS SIT FROM OCCURRING. FROM PREVIOUS ENCOUNTERS AND OUR RADAR PICTURE WE KNEW TO FLY THE REQUESTED 290 DEG HDG WOULD HAVE BEEN EXTREMELY DANGEROUS. THE ATC'S ULTIMATUM OF PENETRATE DANGEROUS WX OR DECLARE A WX EMER AND LOSE ATC SVCS MADE A WX PROB, WORSE.

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.