Another question; this time British Airways. Officially came into existence on 1st April 1974, although Cambrian and Northeast were not integrated for another two years. Looking at some old timetables, the original "BE" and "BZ" prefixes were still in use for the former B.E.A. and Regional Division flights respectively until at least summer 1978. Just wondering if anyone can shed any light on how long it was before "Speedbird" was adopted as the callsign for all BA flights - did this change at the same time as the published timetables changed? Many thanks in advance for any replies.