The Types facet of Aviation Engine Fuel segmentation classifies fuels into four sub‑categories: Jet A‑1, Avgas, Bio‑derived fuels, and Synthetic fuels. Jet A‑1 remains the cornerstone fuel, supplying over 80% of global aviation fuel volume due to its compatibility with modern turbine engines and extensive distribution infrastructure. Avgas, primarily 100LL, serves the piston‑engine fleet within General Aviation, representing a niche yet critical segment. Bio‑derived fuels, including hydroprocessed esters and renewable jet fuel (RJ‑1, RJ‑2), are emerging as a response to decarbonisation mandates, currently capturing a modest share but projected to grow as certification expands. Synthetic fuels, produced via Fischer‑Tropsch or power‑to‑liquid processes, offer carbon‑neutral alternatives and are gaining traction in military and commercial fleets seeking compliance with carbon‑offset programs. Together, these fuel types delineate the market taxonomy and influence investment, supply chain, and policy decisions across the Aviation Engine Fuel market.