A KING AIR CAPT ALTIMETER WAS IN ERROR. THE ACFT WAS REMOVED FROM SVC AFTER RETURNING TO HOME BASE.

Narrative

I AM A PLT IN AZ. I WAS DISPATCHED TO ZZZ TO PICK UP A PATIENT WHO WAS IN CRITICAL CONDITION AND NEEDED TRANSPORT TO ZZZ1. AFTER I WAS HANDED OFF TO ZZZ1 APCH I WAS TOLD I WAS LOWER THAN THE ALT I WAS ASSIGNED AT 8000 FT. THERE WAS A DISCREPANCY BTWN THE PLT AND COPLT'S ALTIMETER; SO I DECIDED TO GO OFF THE ALT MY GPS WAS RPTING. I WAS GIVEN A PHONE NUMBER; AND CALLED WHEN I LANDED. THE PATIENT WAS TRANSPORTED; AND WE LEFT AN HR LATER VFR BACK HOME. I RPTED THE ISSUE TO MY LEAD PLT; AND MAINT DIRECTOR. THEY BOTH TOOK THE PLANE UP WHEN I RETURNED AND NOTED THE ALTIMETER PROB THAT I HAD ENCOUNTERED WITH ZZZ1 APCH; AND DECIDED THAT MAINT NEEDED TO BE DONE. THE LEAD PLT THEN FLEW THE PLANE TO ZZZ3 (THAT DAY) WHERE IT WAS TAKEN OTS; AND MAINT WAS UNDERWAY. THE FOLLOWING DAY IT WAS NOTED THAT THERE WAS IN FACT AN ALTIMETER ENCODING DISCREPANCY BTWN THE PLT AND COPLT'S ALTIMETER; AND A BROKEN PIPE IN THE STATIC SYS. THE ALTIMETER WAS REPLACED; MAINT WAS DONE; AND THE PLANE WAS BACK IN SVC THAT EVENING.