Heat exchangers are fundamental devices playing a vital role in engineering. In aviation sector, heat exchangers are widely used in gas turbine engines. Optimization of heat exchangers in terms of thermodynamic aspect is compulsory. In recent years, heat transfer capacity or ability gains importance in open literature for optimization of heat exchangers. This new term “entransy” is used to explain heat transfer capacity to be used for optimization of heat exchangers. The main objective of this paper is to optimize heat exchangers by using entransy concept for conventional aircrafts. For this purpose, pillow plate heat exchanger system is employed to gas turbine engine. Entransy analysis is used to analyze and optimize pillow plate heat exchanger by using kerosene as main fuel. The analyzed system provides entransy transfer efficiency of 36%. It is attempted to use both pillow plate heat exchanger system and entransy analysis for conventional aircrafts and bring a novelty to open literature.