The aviation industry is under increasing pressure towards electrification followingthe automotive industry’s success on doing so. This is true particularly in Europe,where the aim is to achieve Net Zero CO2 emissions by 2050. This paper proposes adown-to-earth range expectation of three sustainable regional aircraft concepts whileexploring their economic viability for flying the Swedish domestic airspace in 2030and 2040. Rather than introducing a new design, three existing fully electric aircraftconcepts, the Eviation Alice and the EL19, as well as a hybrid-electric aircraftDornier 328, were modelled and evaluated. Using a technology forecasting methodology,realistic performance parameters for battery specific energy were estimatedto provide feasible expected operational ranges, which for 2030 are not expected toexceed the 500 [km] of useful range but for the 2040 scenario they could connectthe whole of Scandinavia. Acquisition and direct operating cost assessments wereconducted comparing these aircraft with the ones they intend to replace, such as theATR 72-600 and the DHC Twin Otter. The preliminary findings indicate that whilethe fully electric aircraft can potentially cover significant domestic routes in Swedenby 2040, their acquisition and direct operating cost remain a challenge for thenear future. Besides, a Modelica-based model of a parallel hybrid-electric propulsionsystem was modelled using thermodynamic equations for the internal combustionengine and a mathematical characterization of the efficiency map of an electric motor.The model estimates behaviour of both powerplants in the transitory state, aswell as emissions during its operation. This research underscores the importance ofhaving both: a realistic technology forecasting and a financial consciousness for thesustainable aircraft designs. At the same time opens the opportunity for modellingand simulation of missions using temperature-dependant emission models. All ofthese while proposing possible actions to mitigate this cost difference and make thetechnology attractive for business.