Decarbonizing the aviation industry has become a major focus of attention, which still is 99.7% reliant on fossil-based fuel. A promising solution is the production of Sustainable Aviation Fuel (SAF) from secondary biomass feedstocks such as forestry residues. For the Netherlands, studies estimate a substantial supply of forestry residues for bioenergy purposes by 2050. This study addresses the question under which conditions SAF production from forestry residues can become economically feasible in the Dutch context. Thermochemical pathways including Gasification Fischer-Tropsch (GFT) and Hydrothermal Liquefaction (HTL), followed by dedicated SAF refinery processes, offer potential conversion routes. However, a comparative techno-economic analysis for this context is lacking, and existing studies often neglect the effects of technological learning and CO2 capture and storage on performance outcomes. This study evaluates feasibility by comparing the techno-economic performance of GFT and HTL. Process designs for both pathways are developed and these are side-by-side assessed on technical performance, cost structure, sensitivity to key parameters, and two potential scenarios. Results show that HTL achieves 47% higher SAF yields (18.3%) and a lower minimum fuel selling price (MFSP) of €1.03/L compared to GFT (10.2% yield and €1.49/L MFSP). Nonetheless, under the base scenario both pathways remain uncompetitive with fossil kerosene (€0.50/L). However, under the optimum progressive scenario, HTL achieves competitiveness with an MFSP of €0.30/L, while GFT reaches €0.50/L, positioning HTL as the more promising pathway in the Dutch context. However, supportive policy frameworks are needed to accelerate deployment of these technologies.