Intermetallic TiAl alloys are already used as engineering lightweight high-temperature materials in aircraft and automotive engines. In this presentation the alloy design rules, which have been applied for the development of a β-solidifying γ-TiAl-based alloy, the so-called “TNM alloy” with excellent hot-deformability, will be explained. The TNM alloy is already used in a particular eco-friendly and fuel-saving aero-engine, which is powering the Airbus A320neo. Besides the considerations which have led to the selected alloying elements, the heat treatments conducted subsequent to conventional hot-forging are discussed. In this context it will be shown how novel characterization techniques, e.g. in-situ high-energy X-ray and neutron diffraction, have been employed to accelerate both alloy and process development. The microstructural parameters, which influence the elongation at fracture and creep behavior will be emphasized. Finally, the potential to improve the mechanical properties of the TNM alloy by means of micro-alloying with C and Si is addressed.