The ALTTA project advances hybrid laminar flow (HLF) technology with the aim of reducing the aerodynamic drag of an aircraft by delaying the laminar/turbulent transition. The technology will be applied to fin and nacelle with emphasis on less complex systems. A simplified suction leading edge for the fin of a narrow body aircraft will be designed and realized as full-sized mock-up using a new manufacturing technique. An HLF nacelle will be designed for better trade-off between aerodynamic drag reduction and penalties caused by the addition of a suction system. For this nacelle, a combined anti-icing and anti-contamination system will be developed, manufactured, and implemented in a mock-up. ALTTA will contribute to the aerodynamic design of HLF applications by improving transition prediction techniques from data base methods to linear and non-linear stability codes. Furthermore, a generic tool to optimise the trade-offs of HLF applications will be developed and the system tools for laminar flow applications will be improved.