What was found
**ATB - EMERGENCY DECLARED**LOST CAPT AIRSPEED ON TAKEOFF, PERFORMED UNRELIABLE AIRSPEED V LIST, EICAS SHOWED RUDDER RATIO AND MACH IAS.ON CLIMB OUT F/O'S AIRSPEED DROPPED SIGNIFICANTLY, GOT F/O'S STICK SHAKER. AIR TURN BACK NOTE: RUDDER RATIO EICAS MSG ADDRESSED ON LINE ITEM #4. CW CAPT'S AND F/O'S ADC BITE TEST PER FIM 34-12 FAULT TREE 813, FIG 109. NO DEFECTS FOUND, PURGED LINES FROM CAPT'S AND F/O'S ADC PER AMM 34-11-01-167-004 TO PITOT TUBES, REMOVED ALL DEBRIS BLOCKING BOTH PITOT TUBES. CW PITOT PROBE TEST OF CAPT AND FO'S PITOTS. POS CK NORMAL PER AMM 34-11-01-755-033.