Chapter 4 Powerplants Introduction This chapter covers the engines found on most weight-shift  control (WSC) aircraft and includes the exhaust, ignition,  lubrication, cooling, propeller, gearbox, induction, charging,  and fuel systems. Reciprocating engine operating theory is  covered for both two-stroke and four-stroke engines. The  WSC engine and propeller, often referred to as a powerplant,  work in combination to produce thrust. The powerplant  propels the aircraft and charges the electrical system that  supports WSC operation.