PAIRED TOGETHER FOR FIRST TIME; GLF5 FLT CREW DEPARTS HPN WITHOUT TKOF CLRNC.

Narrative

I WAS TOLD THAT THE OTHER PLT WAS AN ACCOMPLISHED AVIATOR; TYPED IN THE G5 AND NUMEROUS OTHER ACFT WITH OVER 14000 HRS OF FLT TIME. HE TOLD ME THAT HE LIVES IN THE NORTHEAST AND IS FAMILIAR AND COMFORTABLE OPERATING AT HPN AND HAS DONE SO FOR MANY YRS. BECAUSE HE WAS FAMILIAR WITH THE ROUTING FROM HPN TO BOS I DECIDED THAT HE SHOULD FILE THE FLT PLAN. THE NEXT MORNING WE DROVE TO HPN; ARRIVING AT XA00 FOR A SCHEDULED DEP AT XB30. THE OTHER PLT TOLD ME HE HAD RECEIVED THE CLRNC FROM NEW YORK DEP. THE OTHER PLT TOLD ME THAT HPN TWR OPENED AT XC00. THAT BEING SAID; AFTER ENG START AND BEFORE TAXI; HE WAS USING THE CTAF FOR HPN. I ASSUMED HE XMITTED ON THAT CTAF AND WE TAXIED TOWARD THE ACTIVE RWY. ON THE TKOF BRIEFING I ASKED THE OTHER PLT IF HE WOULD CONTACT NEW YORK DEP BEFORE TKOF. HE TOLD ME THAT ATC SAID WE COULD DEPART VFR AND PICK UP THE CLRNC AT 3000 FT; SO I TOLD HIM TO XMIT OUR INTENTIONS. AFTER MAKING SURE THE RWY AND AREA WAS CLR WE TOOK THE ACTIVE AND DEPARTED. UPON REACHING 3000 FT HE CONTACTED NEW YORK DEP. AT THAT POINT THEY INFORMED US THAT WE HAD DEPARTED HPN WITHOUT A TKOF CLRNC. I WAS SHOCKED BECAUSE THE OTHER PLT HAD PREVIOUSLY TOLD ME THAT HPN TWR OPENED AT XC00. I TRUSTED THE OTHER PLT AND ASKED HIM ALL THE PERTINENT QUESTIONS AND I RECEIVED ALL THE CORRECT ANSWERS. I FIND IT HARD TO BELIEVE THAT AN AVIATOR WITH THAT EXPERIENCE CANNOT USE THE VHF COMS PROPERLY IN THE G5. LATER THAT MORNING; I SPOKE TO THE TWR MGR AT HPN AND EXPLAINED THE FACTS OF THE INCIDENT. HE INFORMED ME THERE WERE NO TFC CONFLICTS DURING OUR DEP AND FOR THAT I AM GRATEFUL.