RPTR DID NOT GO DIRECT TO VOR AS ASSIGNED THINKING IT DID NOT MATTER AND THE VOR WAS OUT OF INTENDED DIRECTION OF FLT BY 10 MI IN THE OPPOSITE DIRECTION.

Narrative

WE OBTAINED IFR CLRNC TO DEPART THE COATSVILLE ARPT; 40N; (DEST PIT) FROM PHILADELPHIA CTL; ON THE GND. CLRNC WAS '...DIRECT THE MODENA (MXE) VOR; THEN VIA THE 276 RADIAL...CLB TO 3000 FT.' BECAUSE WE WERE DEPARTING ON RWY 29; AND THE MXE VOR WAS BEHIND US; I ELECTED TO MAKE A L TURN TO INTERCEPT THE MXE 276 RADIAL; RATHER THAN COME BACK TO THE E TO THE MXE VOR. AS WE WERE INTERCEPTING THE 276 RADIAL; PHIL DEP ASKED IF WE WERE PROCEEDING DIRECT THE VOR. WE RESPONDED; 'NO; WE ARE OUTBOUND ON THE 276 RADIAL.' WE WERE IMMEDIATELY INSTRUCTED TO TURN L AND PROCEED DIRECT TO THE MXE VOR. SEVERAL THINGS CONTRIBUTED TO THIS INCIDENT: 1) RECEPTION ON THE GND WHEN OBTAINING THE CLRNC WAS VERY POOR. WE HAD TO MAKE NUMEROUS ATTEMPTS FOR CLARIFICATION AS THE CTLR'S XMISSION KEPT BREAKING UP. IF IT WAS COMMUNICATED; THE IMPORTANCE OF PROCEEDING DIRECT TO THE MXE VOR WAS NOT RECEIVED. 2) I ASSUMED THE 'DIRECT MXE VOR' PART OF THE CLRNC WAS JUST A FORMALITY; AND SINCE WE WERE DEPARTING IN THE OPPOSITE DIRECTION FROM THE VOR; IT WOULD BE OK TO INTERCEPT THE OUTBOUND RADIAL W OF THE VOR. THIS IS DONE ROUTINELY IN THE ATC SYS. I NOW UNDERSTAND THIS WAS NECESSARY TO KEEP US WITHIN PHILADELPHIA'S AIRSPACE. SOME OBSERVATIONS: 1) I ASSUMED! ASSUMING WILL BITE SOONER OR LATER. WE SHOULD HAVE COMMUNICATED OUR INTENTIONS TO ATC AS SOON AS CONTACT WAS MADE ON CLBOUT. THIS WOULD HAVE CLARIFIED THE SIT. 2) IN THIS CASE; I BELIEVE ATC SHOULD INSURE THE CREW UNDERSTANDS THE IMPORTANCE OF THE CLRNC AS GIVEN. I'M CERTAIN THIS WILL HAPPEN AGAIN TO SOME UNSUSPECTING CREW UNLESS A CHANGE IS MADE IN THIS REGARD.