The BAC One-Eleven 475 was the 'hot and high' version of this bus-stop jet, combining the -500s more powerful Spey engines with the lighter -400 airframe, and at cold wet Farnborough it gave a lively show....Noisy, though!

This One-Eleven was retained by the BAC/BAe throughout its 29-year flying career for use as a development and test aircraft for the production variants and for testing technical innovations. One such deveopment is alluded to by the 'Fly-By-Light Flight Control Technology' titles where it was thought that if the flight control inputs were driven by light rather than electrical inputs, then these would be much harder for any putative enemy to jam.