DORNIER SA228 PLT HAS AN ALTDEV DURING AN INST CHK RIDE.

Narrative

THE PLT HAD BEEN HAVING ALT CTL PROBS DURING THE FLT FROM SAC TO SCK; BUT HAD KEPT IT BTWN 100 FT LOW TO 100 FT HIGH. IT WAS SOMETHING I WAS GOING TO DISCUSS ONCE WE WERE ON THE GND. WE CONDUCTED AN ILS WITH A FULL STOP AND A TAXI BACK WITH A REJECTED TKOF. ONCE OFF WE WENT TO THE VOR AND HELD THERE. AGAIN ALT HOLD WAS AN ISSUE DURING THE HOLD. THE VOR APCH WAS COMPLETED AND THE PLT REQUESTED A PUBLISHED MISSED APCH TO ORANG. THE CTLR ISSUED THE CLRNC AND GAVE AN ALT OF 3000 FT. I ASKED THE PLT TO ARRANGE FOR BLOCK ALT TO DO SOME AIR-WORK AROUND WAGER. THE CTLR TOLD THE PLT THAT HE DIDN'T THINK THAT HE COULD ARRANGE AN IFR CLRNC; BUT ASKED IF HE COULD DO IT IN VFR. THE PLT TOLD THE CTLR; THAT'S OK. THE PLT WAS CLRED TO WAGER INTXN AND STARTED TO INPUT WAGER INTO THE GPS UNIT AS HE APCHED ORANG. HE ENTERED THE WRONG NAME AND HAD TO LOOK ON THE MAP. I WAS TRYING TO LOOK OUTSIDE FOR TFC AND WHEN I LOOKED BACK INTO THE COCKPIT THE ALTIMETER READ 3600 FT. I WAS NOT SURE IF I HAD MISSED THE CLRNC OR MISUNDERSTOOD THE CTLR IN REGARDS TO THE VFR VERSUS IFR BECAUSE OF MY PREVIOUS HEADSET PROBS. I OBSERVED A CESSNA COMING TOWARDS US JUST AS THE CTLR ASKED WHAT THE PLT WAS DOING. THE PLT QUICKLY PUSHED THE NOSE DOWN AND AGAIN TRIED TO INPUT WAGER. I WAS NOT SURE IF WE HAD A PLTDEV AT THAT TIME AS I WAS STILL UNSURE OF THE STATUS OF THE FLT BEING IFR OR VFR. THE CTLR SOLVED THAT PROB WHEN HE INFORMED THE PLT TO CALL THE CTR. THE PLT ASKED WHAT THAT MEANT FOR THE CHK RIDE AND I INFORMED HIM THAT IT WAS AN UNSATISFACTORY.