What was found
NR 1 IRU DEFERRED. ON TAKEOFF ROLL, ALL CAPT AIRSPEED SYMBOLOGY ON AIRSPEED TAPE DISAPPEARED (V1, V2, GREEN DOT, ZIPPER ECT.) WITH FLASHING "SPD LIM" IN RED IN LOWER LEFT CORNER OF PFD. SELECTED ADC INST, SYS 2 ON CAPT SW PANEL. ALL OTHER AIRSPEED INDICATIONS NORMAL. REPLACED NR 1 FAC REF MM 22-26-34-4. CKS NORMAL REF10-00-5 AND MM 22-40-00-5. A/C REMAINS CK 3A, CK 3A, CAT 2. R/I FROM FACT PREMATURE REMOVAL/INSTALLATION OFF MFG B471AAM6, POS 1 SRL 115.