Formalization of Hindsight Indicators and Characteristics for Assessing Foresight of Transport and Passenger Aircraft

ABSTRACT This study develops a unified methodological framework for assessing the prospective development of passenger and transport aircraft through the formalization of hindsight indicators and the rational evaluation of technical characteristics. A hierarchical representation of the aircraft as a complex technical system (CTS) is constructed, enabling the decomposition of subsystem properties and the definition of rational benchmark values for key parameters. A comparative method based on the degree of rationality is proposed to evaluate the technical perfection of existing and future aircraft and to identify subsystem-level weaknesses, reserves, and integrative effects. To support foresight analysis, a transport-system indicator (NTS) is introduced and applied to a curated dataset of current and advanced aircraft projects. Interpolated hindsight envelopes are derived, defining the feasible domain of flight-performance combinations achieved by state-of-the-art designs. The method allows quantitative determination of whether a proposed future aircraft represents a continuation of existing technological trajectories or a potential breakthrough. The results demonstrate that rationality-based indicators, combined with hierarchical CTS structuring and hindsight-derived envelopes, provide a systematic approach for guiding early-stage design decisions, prioritizing research directions, and evaluating the plausibility of prospective configurations in both civil and prospective hybrid-propulsion aircraft development.