The environmental and health impacts of soot produced by jet aircraft have gained significant attention. In this paper, high-resolution electron microscopy (HRTEM) and X-ray photoelectron (XPS) data are reported for physical and chemical characterizations of particulate emissions from GE CFM56-2C1 engines on a commercial DC-9 aircraft burning petroleum based - JP-8, and synthetic -HRJ (hydro-treated renewable jet) & FT (Fischer-Tropsch) fuels. Soot physical macro-, micro- nano-structure, and chemical composition are discussed with respect to combustion conditions. Nanostructure of JP-8 derived soot shows a progression from amorphous to graphitic-like as a function of increasing engine power level. However, HRJ and FT derived soot exhibit significant nanostructure across all power levels. Kinetic simulation also indicates that C5 formation -a key member for carbon lamella curvature-is strongly dependent on temperature and fuel-air equivalence ratio. Results are interpreted in terms of different soot formation regions with associated variations in temperature and local equivalence ratio. The driver for such differences is the initial fuel composition.