As fuel efficiency becomes a greater concern in aero engine design and operation. To meet this need, a new methodology is being developed here that proposes the use of exergetic metrics for mapping the exergy flows throughout high bypass turbofan engine at maximum thrust level for its sustainability assessment. The engine (net thrust force of 206 kN) studied here is used in the first wide body, dual-aisle, and the largest commercial aircraft. The findings of sustainability analysis reveal that exergy efficiency of the engine is 29.6% having exergy destruction factor of 0.5037. In addition, environmental effect factor of the turbofan engine is found to be 0.675, while exergetic sustainability index is calculated to be 1.48. In the case study, recoverable exergy amount of the engine is zero since the emissions released from exhaust cannot be recoverable in the engine. As a conclusion, exergetic sustainability method is an effective way to assess the sustainability of aircraft and aero engines and provides a good tool for designers, users, decision makers and researchers in green air transportation. Hence, these parameters make the engine and aircraft more environmentally benign and more sustainable. (C) 2015 Elsevier Ltd. All rights reserved.