Trident was another , ahead of the 727 at the start but strangled by BEA requirements. No mention on the film of the Vickers airliner cancelled just before completion. Most of it comes down to government , being simplistic, they owned the airlines BOAC/BEA , they controlled the manufacturers with contracts for MOD etc . When you read the history of this era its amazing we did as well as we did. Sad thing on last nights programme was no mention on the comet disasters how all the lessons learned were freely shared with the americans etc to enable them to incorporate the lessons learned.