The aviation sector's transition toward sustainable energy sources necessitates rigorous evaluation of alternative fuels under real operating conditions. This study presents an exhaustive and systematic experimental investigation of a GTM400 micro-turbojet engine operating on conventional Jet-A1 and six alcohol-blended fuels (5% and 10% ethanol, butanol, and isopropanol by volume). Comprehensive performance mapping was conducted across the entire operational envelope (idle to 100% relative thrust), with detailed analysis of temperature profiles (T3, EGT, TiT), thrust-specific fuel consumption (TSFC), thermal efficiency, specific thrust, and fuel-to-air ratios. Results indicate that alcohol blends can significantly improve high-load performance through enhanced combustion efficiency, with 5% isopropanol achieving an 11.6% thrust increase (t(2) = 15.29, p = 0.004), while 5% ethanol achieved the lowest TSFC (2.4% reduction, p = 0.019). The underlying physical mechanisms are discussed. The findings provide critical insights into combustion behaviour, thermal management, and efficiency gains. Environmental benefits, including expected reductions in particulate matter and CO emissions, are consistent with trends reported in prior combustion studies of alcohol-blended kerosene [7, 26], though direct emissions measurement is recommended in future work. The findings support the integration of alcohol-based sustainable aviation fuels into future propulsion systems.