Originally Posted by
pax britanica
Re the trident vs 727 I understood that Boeing did visit Dh but I doubt that the whole concept cme from their.
Yes Shirer (Boeing Chief Engineer) and his team were "shown all" at DH's and a fortnight later announced the 727. "in early 1960 Hatfield accepted a return visit to Boeings and were politely received and told nothing". (as above this is from a senior de Havilland executive closely involved at the time.)
ETA SSD is right that you don't plan for now but for the future, hence the A300 and A380 had considerable capacity increases over what existed and were ready to go into service when needed