PVT PLT IN SMA GETS DISORIENTED DURING ILS APCH ATTEMPT.

Narrative

WAS ON A PLANNED VFR FLT TO RIVERSIDE ARPT IN TULSA. UNPREDICTED CLOUDS FORMED WITHIN 15 MI OF DEST. I REQUESTED IFR APCH; WHICH WAS GRANTED. I REACHED FOR APCH BOOK LOCATED IN BACK SEAT WHILE STILL ABOVE CLOUDS IN GOOD VFR ON TOP. AS I GRABBED THE BOOK; I LOST HOLD AND TORE THE PLATE NEEDED. INSTEAD OF CANCELING; I PROCEEDED WITH APCH. I ASKED FOR VERIFICATION OF ILS FREQ AS THAT AREA OF PAGE WAS BARELY READABLE; EITHER THROUGH INCORRECT WRITING OF FREQ OR INCORRECT GIVEN DIALED IN WRONG ILS FREQ CAUSING MISSED INTERCEPT STILL VFR. ONCE FREQ WAS CORRECTED; BEGAN APCH AGAIN. INTERCEPT WAS MADE BUT POORLY FLOWN ON MY PART. NO OM WAS RECEIVED AND WAS WITHIN 2 MI OF ARPT WHEN BECAME DISORIENTED. I IMMEDIATELY BEGAN TO CLB AND CALLED THE MISS. WAS GIVEN CLB ON COURSE TO 2500 FT WHICH WAS STILL IN CLOUDS. REQUESTED 2700 FT; WHICH WOULD PUT ME ON TOP. APCH WAS UNABLE TO GIVE 2700 FT SO GAVE 2500 FT AND COURSE OF 270 DEGS. WHILE TURNING TO 270 DEGS; DIRECTIONAL GYRO PRECESSED AND I TOOK HDG OF 285 DEGS (COMPASS) WHILE SHOWING 270 DEGS ON DIRECTIONAL GYRO. CONDITIONS WERE LOWERING; BOTH ACFT IN FRONT AND BEHIND RPTED MARKER OTS. I THEN REQUESTED CLB TO VFR AND TOOK VFR FOLLOWING TO OKMULGEE; WHICH WAS 1800-2000 FT BROKEN WITH 15 MI VISIBILITY. IN RETROSPECT; SINCE FLT WAS PLANNED VFR AND FLOWN VFR; SHOULD HAVE DIVERTED TO OKMULGEE INSTEAD OF REQUESTING APCH. MY MULTIPLE ERRORS IN PROC WERE BLATANTLY POOR FLYING WHICH COULD HAVE HAD DISASTROUS RESULTS. CONSIDERATIONS: POOR PLANNING IN COCKPIT ARRANGEMENT RESULTING IN ONLY PARTIALLY USABLE APCH PLATE; POOR JUDGEMENT IN ATTEMPTING APCH; POOR PLTING DUE TO ABOVE.