What was found
ON TAKEOFF ROLL AT 70 KTS THE FOLLOWING EICAS MESSAGES APPEARED: YD OFF LOWER, MACH TRIM OFF, FGC ADC MISCOM, ABORTED TAKEOFF. DURING VISUAL INSPECTION NOTED A BLOCKAGE IN THE RT PITOT TUBE, PURGED RT PITOT LINE AND PITOT TUBE, NOTED MUD LIKE SUBSTANCE WAS REMOVED DURING PURGING. PERFORMED PITOT STATIC LEAK CHECK AND ADC SYSTEMS CHECK, OPERATIONAL TEST OF BOTH SYSTEMS CHECK GOOD. WORK DONE IAW CESSNA 750 MM CHAPTER 34-11-08.