FLC OF AN MLG ACR ACFT DEVIATED FROM ASSIGNED HDG DUE TO WX.

Narrative

AFTER SWITCHING FROM ZBW TO ZNY; THE FIRST ZNY CTLR WE SPOKE WITH RERTED US AS FOLLOWS BECAUSE OF WX: RADAR VECTORS CYN; V1 TO INTERCEPT V-268 BAL. WE WERE IN THE CLR AT THE TIME; AND IT APPEARED THAT OUR FILED ROUTING WOULD KEEP US IN THE CLR AND BEHIND MOST OF THE FRONTAL ACTIVITY. IT ALSO APPEARED THAT THE RERTE WOULD TAKE US THROUGH THE FRONTAL ACTIVITY SHOWING CLRLY ON OUR RADAR. ACCORDINGLY; THE CAPT (I WAS FO AND FLYING) QUESTIONED ZNY ABOUT THE RERTE AND POINTED OUT THAT OUR FILED ROUTING WOULD KEEP US IN THE CLR. THE ONLY PRECIPITATION WE WERE SHOWING AT THAT TIME ON OUR RADAR WAS A SCATTERED AREA ABOUT 150 MI FROM OUR POS; NE OF OUR DEST; BWI. AFTER A COURTEOUS AND RELAXED DISCUSSION; ZNY APPROVED OUR REQUEST TO STAY ON OUR ORIGINAL RTE. AS WE APCHED MXE; DSNDING TO FL190; THE AREA OF PRECIPITATION WE HAD SEEN EARLIER APPEARED TO BE GROWING AND WAS LOCATED JUST TO THE N OF V378 S OF MXE. AT THIS TIME WE WERE SWITCHED TO ANOTHER ZNY CTLR. THE CAPT REQUESTED PERMISSION TO STAY ON OUR PRESENT HDG OF 235 DEGS AFTER PASSING MXE; THE AIRWAY RADIAL WAS 245 DEGS. WE WERE NOW IN CLOUDS; AND IN AND OUT OF PRECIPITATION. THE CTLR'S RESPONSE TO THE CAPT'S REQUEST WAS UNREADABLE; PRESUMABLY BECAUSE OF PRECIPITATION STATIC. THE CAPT TOLD HIM AGAIN OF OUR DEV; 10 DEGS L; AND SAID HIS LAST XMISSION HAD BEEN UNREADABLE. PRESUMABLY ON A BACKUP XMITTER; THE CTLR ORDERED US TO MAKE AN IMMEDIATE R TURN TO 320 DEGS. THIS HDG; 75 DEGS TO THE R OF OUR FILED AIRWAY ROUTING AND 85 DEGS FROM OUR PRESENT HDG; WOULD HAVE TAKEN US DIRECTLY INTO A RED AREA SHOWN ON OUR WX RADAR. THE CAPT DECLINED THE HDG. THE CTLR TOLD US TO SQUAWK EMER; 7700; ON OUR XPONDER. SIMULTANEOUSLY WE WERE ABLE TO START TURNING BACK TOWARD THE AIRWAY. THE CAPT ADVISED HIM OF THIS; AND HE TOLD US TO RETURN TO A NORMAL SQUAWK AND TURN TO 270 DEGS WHEN ABLE. WE WERE ABLE AT THIS TIME TO FLY 270 DEGS WITHOUT GOING THROUGH ANY HAZARDOUS LOOKING WX AS SHOWN ON OUR RADAR. THE CAPT QUESTIONED THE CTLR ABOUT HIS INSTRUCTIONS TO SQUAWK EMER AND TURN INTO A TSTM. THE CTLR ANSWERED THAT A PREVIOUS CTLR HAD TOLD US THAT NO SOUTHERLY DEVS WOULD BE ALLOWED. THIS WAS INCORRECT -- NO SUCH INSTRUCTION HAD BEEN GIVEN. THE CTLR SAID IT WAS A HDOF PROB WITH ZDC. THERE WAS NO MENTION OF ANY TFC CONFLICT. WE NEVER DID TALK WITH ZDC; BUT WERE HANDED OFF DIRECTLY TO BWI APCH CTL; WHICH PROMPTLY CLRED US DIRECT TO BAL. OUR IRS NAV INDICATED THAT WHEN THE CONFLICT BTWN OUR OPERATIONAL REQUIREMENTS AND ZNY'S NEEDS BEGAN; WE WERE 3.3 NM S OF OUR FILED RTE; WITH ONLY A 10 DEG L DEV WHICH WE NEEDED TO MAINTAIN FOR PERHAPS 1 OR 2 MINS. ALSO; BY GOING S OF THE WX; WE WERE MAKING THE SMALLEST COURSE DEV AROUND IT. THE CRUX OF THE PROB WAS THE ZNY CTLR'S UNDERSTANDING THAT WE HAD BEEN TOLD 'NO S DEVS;' WHEN IN FACT WE HADN'T BEEN TOLD THIS. CONTRIBUTING WAS THE RIGIDITY OF A SYS WHICH PRODUCED WHAT APPEARED IN OUR COCKPIT TO BE A VIRTUAL PANIC REACTION -- INSTRUCTIONS TO TURN INTO A TSTM AND SQUAWK EMER -- NOT BECAUSE OF ANY CONFLICT WITH OTHER ACFT; BUT BECAUSE OF OUR APCHING A POINT; IN THE CTLR'S WORDS; 'WITHIN 2.5 MI' OF ZDC AIRSPACE.