The aviation industry's strategic significance as a key driver of the global economy and a catalyst for technological development has established investment in this sector as a criterion of national development. A country's economic advancement through its aviation industry hinges on the optimal performance, safety, and reliability of its air fleet, which in turn depends on Maintenance, Repair, and Overhaul (MRO) processes. Accordingly, this study aims to identify criteria that—by driving a transformation in aviation MRO toward Maintenance 4.0, under Fourth Industrial Revolution requirements—can both assess the quality of this industry and contribute to its improvement. Given the rich literature in this field, the first stage employed a seven-step meta-synthesis method to review relevant literature in reputable Scopus-indexed journals, yielding 94 final scientific documents. Using qualitative content analysis and a three-stage coding technique, the findings were organized into 455 open codes, 24 axial codes, and six selective codes. The selective codes comprise: (1) Intelligent Computing & Analytical Core; (2) Cyber-Physical Digital Infrastructure; (3) Proactive Maintenance & Health Management Strategy; (4) Smart MRO Operations, Logistics & Automation; (5) Human-AI Collaboration & Workforce Enablement; and (6) Safety, Trust & Regulatory Governance—each holding importance proportional to its frequency in the literature. These criteria constitute a roadmap enabling the aviation industry to undergo a fundamental shift from traditional maintenance to Maintenance 4.0, and can guide policymakers and practitioners in enhancing national aviation productivity while driving a substantial leap in economic growth.