What was found
DISCREPANCY BETWEEN AIRSPEED ON CAPT & FO. AT CRUISE .02 MACH & ABOUT 8-10 KNOT DISCREPANCY AT FL 340. ALSO RECEIVED A MOMENTARY OVERSPEED WARNING AT FL 340 IN SMOOTH AIR, CAPT SHOWED .80 MACH & FO SHOWED .82. FO AIRSPEED SEEMS CLOSER TO STDBY AIRSPEED ON BOTH SIDES. AMM 34-11-15-06 DURING DEBRIEF CAPT REPORTS OVRSPD DURATION OF APROX 4 SECS, SUSPECTED ERROR WAS WITH CAPTS IND DUE TO FOS MATCHING STDBY. POST DEBRIEF INSPECTED PITOT PROBES & DISCOVERED FOREIGN MATERIAL JAMMED IN CAPTS PITOT PROBE. AMM 34-11-15-06 REMOVED FOD FROM CAPTS PITOT TUBE IAW AMM 34-11-15-06 INSPECTED FO & STDBY PROBE NO DEFECTS NOTED. INSTALLED CAPTS PITOT PROBE, ALL OPS &LEAK CHECKS GOOD.