SMA PENETRATES TCA. PLT HAS EXPIRED MEDICAL.

Narrative

I WAS FLYING WITH AN EXPERIENCED ATP PLT. HE IS THE OWNER/OPERATOR OF THE ACFT. BEFORE THE FLT HE TOLD ME THAT HE WOULD FLY THE ACFT TO OUR DEST. I UNDERSTOOD THIS TO MEAN THAT HE WOULD BE THE PIC. IN THE CLBOUT PHASE OF FLT I NOTICED THAT WE WERE APCHING THE FLOOR OF THE SEATTLE TERMINAL CTL AREA. I ALERTED THE PLT TO THIS FACT AND HE RESPONDED THAT HE WAS COMMUNICATING WITH ATC. THIS; I BELIEVE IS WHERE THE PROB STARTED. I LATER LEARNED THROUGH TALKING TO THE PLT THAT HE IN FACT HAD NEVER CONTACTED ATC AND HAD ONLY BEEN COMMUNICATING WITH BFI TWR. IN ADDITION; THE PLT SEEMED TO HAVE NO IDEA THAT ANYTHING WAS WRONG WITH HIS PROCS. APPROX 30 MI N OF BFI THE PLT WAS TOLD BY ZSE THAT A NEAR MISS HAD OCCURRED INVOLVING HIS ACFT AND AN AIRLINER. THE RPT WAS SAID TO HAVE ORIGINATED BY THE AIRLINE CREW. THE PLT WAS THEN GIVEN A TELEPHONE NUMBER TO CALL UPON LNDG. THE PLT THEN INFORMED ME THAT HE WAS UNSURE OF THE STATE OF HIS MEDICAL CERTIFICATE AND THAT HE THOUGHT I MIGHT TECHNICALLY BE THE PIC. THIS IS A CLASSIC BREAKDOWN IN COM COMPOUNDED BY AN OLD PLT THAT HAS ONLY BEEN FLYING HVY ACFT FOR A LONG TIME AND WAS VERY UNFAMILIAR WITH VFR PROCS. TO ENSURE THAT A SIT LIKE THIS DOES NOT ARISE AGAIN; I WILL BE SURE TO CHK THE CREDENTIALS OF ANYONE I FLY WITH. FURTHERMORE; I WILL BE MORE ACTIVE IN ASSISTING THE PF EVEN IF THEY ARE FAR MORE EXPERIENCED AND FAMILIAR WITH THE AREA.