Aviation is one of the fastest-growing sources of harmful gaseous emissions to the atmosphere. These emissions give rise to important environmental concerns regarding their global impact and their effect on local air quality at ground level. Aircraft engines account for 2% of all human induced carbon emissions and 12% from transportation sources. Exergoenvironmental analysis of a gas turbine cycle is the combined study of component-wise exergy analysis and the impact of emissions on the environment. The current fossil fuel scenario and the abrupt environmental changes on the earth compels mankind to think about how to increase thermal efficiency of an engine with least possible emission. Aircraft engines based on modified gas turbine cycle are gaining popularity due to their reduced specific fuel consumption, better thermodynamic performance and reduced emissions. The present work reports a comparison of thermodynamic performance, exergy analysis, NOx and CO emission for basic gas turbine cycle (BGT) and intercooled recuperated gas turbine (IcRcGT) cycle based engines used by the aviation industry to act as auxiliary power unit (APU). In addition to this environmental sustainability index of these two cycles is also emphasized. Various cycle operating parameters such as compressor-pressure-ratio (rpc), combustor-primary-zone-temperature, equivalence-ratio, and residence time of gas turbine based cycles has been examined. When gas turbine is operating at higher turbine-inlet-temperature (TIT), turbine blade cooling is required so the cooled gas turbine has been adopted for analysis. Adoption of the proposed scheme is likely to deliver enhancement in thermal efficiency of around 25% and the exergy destruction in combustion chamber is likely to be reduced by around 14% at an rpc of 14 and TIT of 1500K.