The current research project deals with the analysis and validation of the main helicopter power transmissions recycling processes and the design of recycling protocols in order to make them efficient, profitable and environmentally sustainable. This issue is in the domain of the CLEAN SKY JTI - Green Rotorcraft which has the aim to improve the environmental impact of the components in aeronautic and air transport sectors.The main objective of the project is the developing of cost-efficient and clean recycling protocols for the components of the helicopter power transmission system. The protocols will be based on experimental trials.The activities of the project will rely on four pillars: parts and their coatings, dismantling processes, stripping processes and transformation processes. The general strategy will be:1.- Development of a complete survey of market that surrounding the recycling of HTS. The goal of this study is the best adaptation of the HTS parts to the recycling processes.2.- Study and analysis of all materials and coatings used in the manufacturing of HTS.3.- Matching of each part with the most suitable recycling processes.4.- Quantitative evaluation of the recycling processes.For the validation of the recycling protocols they will be applied in real parts pieces within two different cases:1. GRC 6.3 Tail gear box2. GRC 6.4 Intermediate gear boxWorking procedure will be as follows:• Analysis of the components and filling the bill of materials.• Selection of the possible protocols.• Assessment of the protocols by the application of the spreadsheet.• Select the most economic and environmental protocols.• Recycle each component according to their protocol.• Execution of the tests and analyses to validate each process and the overall recycling cycle.• Cost-effectiveness analysisIn this research project no new technologies for recycling the components of the helicopter transmission systems are going to be developed.