LR35 CREW; UNABLE TO COMMUNICATE WITH ZBW; HAD SYS MALFUNCTION WITH GPS EQUIP AND TURN OFF ASSIGNED RTE TO A VOR RTE.

Narrative

LEAR JET; ACFT X DEPARTED VFR FROM LCI AT APPROX XA20. AFTER DEP; WE RECEIVED AN IFR CLRNC FROM MANCHESTER APCH CTL. WHILE FLYING ON AN ASSIGNED HDG; WE RECEIVED AN AMENDMENT TO OUR CLRNC TO FLY PRESENT POS DIRECT TO HVQ VORTAC. WHILE CONTINUING OUR CLB TO THE ALT RECEIVED IN OUR CLRNC; I PROGRAMMED HVQ VORTAC INTO THE GPS AND DIALED THE HVQ FREQ INTO BOTH NAV RADIOS. AFTER PROGRAMMING THE GPS; A COURSE AND HDG TO HVQ WAS NOT AVAILABLE DUE TO A 'RAIM' WARNING ON OUR GPS UNIT. I WANTED TO RPT OUR NAV SYS WARNING TO ATC; BUT THE FREQ WAS EXTREMELY BUSY AT THAT TIME. THE COPLT (PF) TURNED 30-40 DEGS L OFF OUR WESTERLY ASSIGNED HDG TO PROCEED DIRECT TO HVQ VORTAC ACCORDING TO OUR #1 AND #2 VHF NAV. THE FREQ OF HVQ HAD BEEN TUNED INTO BOTH NAV RADIOS BUT HAD NOT BEEN IDENTED YET. AS WE CONTINUED OUR CLB ON A SW COURSE; I WAS WAITING FOR A FREE AND CLR MOVEMENT TO CONTACT AND ADVISE ATC OF OUR SIT; WHEN; IN FACT; ATC MADE CONTACT WITH US AND TOLD US TO TURN BACK TO A WESTERLY HDG DUE TO TFC. I ADVISED ATC OF OUR SIT AND HE EXPRESSED CONCERN THAT WE DID NOT ADVISE HIM EARLIER. I EXPLAINED THAT I WAS WAITING FOR AN OPENING ON THE FREQ. AFTER SEVERAL MINS; THE 'RAIM' WARNING CLRED ON OUR GPS UNIT AND WE CONTINUED DIRECT TO HVQ VIA OUR OWN NAV.