Complex sentence: In the the late 1950s he was instrumental in developing the tail engine configuration of the de Havilland D.H.121 (later to become the Trident) and the VC10; also introducing the company's first jet services, starting in 1960 with the D.H. Comet.
Split into simpler sentences: In the the late 1950s he was instrumental in developing the tail engine configuration of the de Havilland D.H.121 (later to become the Trident) and the VC10. Shenstone also introduced the company's first jet services, starting in 1960 with the D.H. Comet.