Africa's aviation sector remains structurally underperforming despite its vast demographic and economic growth potential. While the African Civil Aviation Commission (AFCAC) has championed the Single African Air Transport Market (SAATM) as the operative framework for continental liberalization, empirical evidence on the magnitude and distribution of its economic and social returns remains sparse and methodologically fragmented. This paper addresses that gap through a multi-method approach combining panel data econometrics, spatial agglomeration modelling, and a welfare decomposition analysis across 47 African Union member states for the period 2015–2024. Drawing on the gravity model of trade adapted for aviation route density, we demonstrate that full SAATM implementation is associated with a projected 38.4% increase in intra-African passenger volumes, a US$3.7 billion annual GDP contribution, and the generation of approximately 218,000 direct and indirect employment opportunities across the continent. The study further quantifies significant agglomeration effects at emerging hub airports in Nairobi, Addis Ababa, Casablanca, and Lagos, showing that aerotropolis spillovers could amplify regional GDP by an additional 0.4–0.9 percentage points. Analytically, the results expose a persistent implementation deficit: only 38 of 54 AU member states have formally acceded to SAATM as of 2024, and regulatory harmonization under AFCAC's Lomé Declaration mandate remains incomplete in 61% of signatory states. The paper concludes with evidence-based policy prescriptions for accelerating AFCAC-led regulatory convergence, eliminating fifth-freedom restrictions, and deploying a continental route development fund as a market-priming mechanism. These findings carry direct implications for policymakers, development finance institutions, and airline executives navigating the post-pandemic restructuring of African air transport markets.