Concorde is an ogival delta winged aircraft with four Olympus engines based on those employed in the RAF's Avro Vulcan strategic bomber. It is one of the few commercial aircraft to employ a tailless design (the Tupolev Tu-144 being another). Concorde was the first airliner to have a (in this case, analogue) fly-by-wire flight-control system; the avionics system Concorde used was unique because it was the first commercial aircraft to employ hybrid circuits.[1] The principal designer for the project was Pierre Satre, with Sir Archibald Russell as his deputy.[69]