Nowadays, many environmental issues are of concern as a result of conventional energy resources utilization in addition to a rise in energy costs dependent on the rapid consumption of resources. Therefore, sustainability is an important term for the utilization of energy resources. The aviation industry is known to be responsible for 3% of total CO2 emissions concerning global warming. This forces us to investigate the aviation industry, specifically gas turbine aero-engines. Gas turbine aero-engines, working according to the principles of thermodynamics, similar to other energy conversion and generation systems can be evaluated using the first and second laws of thermodynamics. Integrated employment of the first and second laws of thermodynamics, namely exergy analysis, is an effective method for performance evaluation. Additionally, exergo-sustainability also yields beneficial results. In the framework of the current paper, ecological function is defined for a simple gas turbine aero-engine, while exergo-sustainability assessment methodology is also explained. Exergy efficiency of the compressor, combustor, gas turbine and nozzle, as components of a gas turbine aero-engine, is found to be 91.58%, 57.41%, 97.96%, and 61.25%, respectively. On the other hand, the sustainability measures of the evaluated gas turbine aero-engine in order of exergy efficiency, waste exergy ratio, recoverable exergy rate, exergy destruction factor, environmental effect factor and sustainability index are calculated to be 0.28, 0.71, 0.00, 0.69, 2.45, and 0.40, respectively whereas the ecological function is found to be -8732.21 kW.