This was the third DH125 but was the first to be completed at the Chester factory. It was also the first to be built to the Series 1 production standard, as the first two aircraft completed at Hatfield were essentially prototypes. G-ARYC first flew in February 1963 and began its career five months later with Bristol Siddeley, being used to test and develop the relatively new Viper 520 Series engine. Later, when Bristol Siddeley became part of Rolls Royce, it flew as a communications aircraft between Filton and Toulouse for the Concorde Olympus 593 engine program.