The association of a gas turbine with a piston engine is by no means a recent conception. As early as 1924 a Napier Lion Series V engine was equipped with a turbine in the manner shown in Fig. 1, the exhaust gases being fed into the turbine to provide all the power to drive the engine supercharger.

At a later date during the 1939-1945 War, many engines were installed in operational aircraft fitted with “turbo-chargers” of the type shown in Fig. 2, in which an exhaust activated turbine drives a subsidiary blower boosting the air intake of the normal engine supercharger.