I would say early 1980s, since this particular pack, focusing on BA's aircrafts in the 1930s and 1940s was reformatted into the Landor design around 1985 or so, and I have that version. I don't know the entire BA story in terms of playing cards (and gambling is yet another vice disapproved of by CWS) but there was a time when promotional marketing material was popular with airlines and many other areas of hospitality. So cabin crew would give them out to travelling teenagers or families, BA marketing folk would have a few packs in their briefcases. The logic being that people wouldn't throw away something like that, so a visual manifestation of the airline would hang around, giving constant unspoken prompts whenever travel was considered. Historically I think this was the practice of shipping and cruise companies, for similar motives, and of course a practical gift in the days before decent IFE. BA had a range of these cards, including one for Skyflyers, one co-sponsored with Disney, so that Disney characters were on the playing side. The card series above - with historic aircraft - I think stopped in the late 1980s with Landor, and I think there was a version pre-Negus too. However BA did issue packs with the Utopia (ethnic) tail fins on the back, so they were handed out this century, since Utopia was from 1997. These had conventional designs on the playing side.