What was found
AT FL 390, THE AUTOPILOT & AUTO THROTTLES DISENGAGED. THE PILOT'S SIDE AIRSPEED WENT UP 30 KTS ABOVE MMO & ALTITUDE WENT UP 200 FT. ON THE ECL ACTIVE ABNORMAL RECEIVED SIX MESSAGES, AUTO SLATS, ALT MISCOMPAIR, IAS MISCOMPAIR, AIL FEEL, ADS1 FAIL, MACH TRIM FAIL. DESCENDING THROUGH FL 260 RECIEVED A RED X THROUGH THE PILOT'S AIRSPEED & ALTITUDE. BELOW 12,000 FT SAT WAS 0*C & INSTRUMENTS SLOWLY CAME BACK. PURGED OBSTRUCTIONS FROM NR 1 PITOT STATIC SYSTEM LINES. PERFORMED OPS AND LEAK CHECKS OF THE PITOT STATIC SYSTEM. PERFORMED INSPECTION OF THE PITOT STATIC DRAINS FOR CLOGGING, ALL DRAINS CLEAR. ALL MAINTENANCE PERFORMED IAW MM 30-30-00-710-801, 34-11-00-790-801, 34-11-01-200-801 AND 34-11-00-200-801.