MLG PITOT STATIC SYS ICED UP CAUSING LOSS OF CAPT'S SPD RATE INSTS; 1 ENG ERRATIC EPR INDICATION AND ENG VIBRATION.

Narrative

ENG VIBRATION/PITOT STATIC SYS ICING. WHILE IMC AT FL330 IN NAV/PROF A COMPARE SPD ALERT APPEARED ON THE LHMFDU. THE CAPT'S AIRSPD; VERT SPD INDICATOR AND #1 EPR BECAME EXTREMELY ERRATIC. THE #1 AUTOTHROTTLE; YAW DAMPER; RUDDER LATERAL AND STABILIZER TRIM FAULTED. THE FO AND STANDBY INSTS INDICATED NORMAL. THE PF (FO) DISCONNECTED THE AUTOTHROTTLE AND MATCHED N1; N2; AND TURBINE GAS TEMP TO PROVIDE THE REQUIRED THRUST TO MAINTAIN AIRSPD. THE #2 AUTOPLT WAS NOT DISCONNECTED. APPROX 5 MINS AFTER THE #1 PITOT STATIC SYS ICED UP; A #2 ENG VIBRATION ALERT APPEARED ON THE LHMFDU WITH A NOTICEABLE VIBRATION IN THE AIRFRAME. THE #2 ENG WAS RETARDED TO IDLE. NO OTHER FAILURE INDICATIONS WERE NOTED. WE STARTED A DSCNT AND ATTEMPTED TO LEAVE ICING CONDITIONS. DURING DSCNT IN ICING CONDITIONS; BUT AT A WARMER TEMP; CAPT'S FLT INSTS RETURNED TO NORMAL. A DECISION WAS MADE TO DIVERT TO SGF DUE TO ICING CONDITIONS ASSOCIATED WITH A LARGE WX SYS THAT MADE CONTINUATION AT LOWER FLT LEVEL TO DEST IMPOSSIBLE. BELOW 15000 FT ENG VIBRATIONS DISSIPATED. ALL SYS WERE TURNED BACK ON AND UTILIZED. A 2-ENG ILS APCH TO AN UNEVENTFUL LNDG WAS MADE AT SGF.