Thank you rrat - I'll wait a couple of pages and see if anyone else interprets the 'ADIRU' input differently. Are you saying, then, that a low 'detected' IAS will increase effective elevator 'gearing' which will produce a greater THS follow-up movement?
henra - it has been stated that the THS locks in one of the failure modes - ie autotrim ceases to function. Regarding 'translation', I feel that if FCOM Vol 3, Supplementary Techniques, Flight Controls, Flight Mode. (3.04.27 P3) did not mean 'locked' (in English) then it should say so?.