CHALLENGER CL-601 FLT CREW HAS SMOKE IN CABIN/COCKPIT DURING CRUISE.

Narrative

WHILE ENRTE WE EXPERIENCED HF COMMUNICATION LOSS AND SOON THEREAFTER THE CEO ADVISED OF SMOKE IN THE LAVATORY. ABOUT TEN MINUTES INTO THE HF COMMUNICATION ISSUE; THE CEO CAME UP AND ADVISED OF SMOKE IN THE LAVATORY. I ADVISED MY OTHER CREW MEMBER TO GO AND FIND OUT WHAT WAS GOING ON. HE CONFIRMED THAT THERE WAS SMOKE IN THE LAV; AND ABOUT THE SAME TIME I COULD SMELL THE SMOKE IN THE FLT DECK. I THEN IMMEDIATELY TURNED OFF ALL POWER TO THE REAR OF THE ACFT. I THEN PROCEEDED TO PULL ALL CB'S TO THE LAVATORY FOR EXTRA SAFETY MEASURE. THE OTHER CREWMEMBER ADVISED THAT THE SMOKE HAD STOPPED A SHORT TIME LATER AND CONTINUED TO INVESTIGATE. IT APPEARED TO BE THE LAVATORY HOT WATER HEATER OVERHEATED AND THUS CAUSED THE INSULATING BLANKET TO GET EXTREMELY HOT AND BEGIN TO MELT. BECAUSE OF THE FACT THAT WE WERE FAIRLY CERTAIN THAT WE HAD LOCATED THE SOURCE OF THE PROB WE CHOSE TO CONTINUE TO THE DEST ARPT AND LANDED WITHOUT INCIDENT. THE ABOVE WAS RELAYED VIA SAT PHONE; HOWEVER AN EMER WAS NOT DECLARED. WE FINALLY WERE ABLE TO ONCE AGAIN COMMUNICATE ON HF JUST PRIOR TO ENTERING SAN JUAN'S AIRSPACE.