PLT DEVIATED FROM ASSIGNED CLRNC; PENETRATED RESTRICTED AIRSPACE.

Narrative

ON DEPARTING RWY 09 AT YAKIMA ARPT; MY CLRNC WAS TO FLY DIRECT TO THE YKM VOR; THENCE ON V298 NWBOUND; A MAGNETIC COURSE OF 310 DEGS. THE VOR IS LOCATED JUST A SHORT DISTANCE FROM THE ARPT TO THE NE. AFTER LIFTOFF; I FLEW RWY HDG WHILE ATTEMPTING TO IDENT THE VOR AND CENTER THE CDI TO THE VOR. I DID NOT GET AN IDENT OR A TO FLAG; SO EXECUTED A CLBING LEFT TURN TOWARD THE VOR AREA. I FINALLY GOT AN IDENT AND DETERMINED I HAD FLOWN PAST THE VOR TO THE NW. I TURNED BACK TO THE VOR; CONTINUING TO CLB. ATC QUERIED MY INTENT; APPARENTLY NOTING I WAS NOT ESTABLISHED ON COURSE. I ADVISED I WAS RETURNING TO THE VOR AND WOULD PROCEED ON COURSE. AFTER XING THE VOR; I TURNED ON COURSE; BUT AGAIN LOST MY IDENT. MY ORIGINAL INDICATION BEFORE LOSING THE IDENT WAS I NEEDED TO TURN RIGHT TO INTERCEPT THE 310 DEG OUTBND R. I WAS FLYING A HDG OF APPROX 330 DEGS WHEN ATC AGAIN ASKED WHY I WAS OFF COURSE. I REPLIED I WAS NOT RECEIVING THE VOR AND THEY ADVISED I WAS WELL RIGHT OF COURSE AND TO TURN WBOUND; MAINTAINING VFR CONDITIONS; AS I WAS NEARING A RESTR AREA. THEIR ORIGINAL HDG APPARENTLY TOOK ME INTO A PORTION OF A RESTR AREA AS I GOT BACK ON COURSE. IN THE MEANTIME; I DIALED IN THE VOR ON BOTH NAV'S; RECEIVED CLR IDENTS; AND VERIFIED WITH ATC MY POS AS TO WHAT RADIAL I WAS XING. ATC SUGGESTED A RETURN TO THE ARPT BECAUSE OF POSSIBLE UNRELIABLE EQUIP. (THEY ADVISED OTHER ACFT WERE RECEIVING THE VOR WITH NO PROBS.) I DETERMINED TO CONTINUE THE FLT; AS BOTH NAV RADIOS APPEARED TO BE WORKING NORMALLY. MY BIGGEST ERROR AS I SEE IT WAS IN FAILING TO MAINTAIN VISUALLY MY POS (OTHER THAN TERRAIN CLRNC) WHILE DEALING WITH MY PROB. WHEN ATC ASKED MY POS; I BELIEVE I TOLD THEM I WAS NW OF THE VOR WHEN I WAS REALLY NE--A SIMPLE VISUAL CHK WOULD HAVE VERIFIED THIS. I WAS PREOCCUPIED WITH FLYING THE AIRPLANE AND FIGURING OUT WHY I WASN'T PICKING UP THE VOR. (NOTE: PRIOR TO THIS FLT; WE HAD COME INTO YAKIMA FROM PENDLETON; OR ON V4 AND I HAD RECEIVED THE YKM VOR WITH NO PROB.) I DID HAVE 2 PAX AND HAD THEM SCANNING FOR OTHER ACFT; BUT I SHOULD HAVE STAYED MORE AWARE OF MY POS VISUALLY; SO AS NOT TO GET IN THE PROX OF THE RESTR AREA. A SECOND PROB ON THIS SAME FLT DEALT WITH ICING. I HAD FLOWN IN YKM SOME 45 MINS PRIOR TO DEP ON THIS FLT FROM SUN VALLEY; AND HAD BEEN AT 12000' MSL IN THE CLOUDS FROM PENDLETON; OR; TO YKM; WITH NO ICE AT ALL. IN YKM; MY BRIEFING FOR THE FLT TO SEA INDICATED FORCASTED ICING CONDITIONS ALONG THE ROUTE ABOVE THE FREEZING LEVEL TO THE TOPS AT 15000' MSL. SINCE I HAD JUST BEEN THERE; WITH NO ICING. I DETERMINED TO GO. SURE ENOUGH; DURING THE CLBOUT; WE STARTED PICKING UP RIME ICE AT APPROX 9000' MSL; CLBING TO 12000'. WE ABORTED THE FLT; DIVERTING TO ELLENSBURG. I SIMPLY SHOULD NOT HAVE GONE WITH RPTED CONDITIONS; EVEN THOUGH I HAD NOT EXPERIENCED ICING ON THE EARLIER FLT.