Rolls-Royce has announced a further key milestone has been achieved in its hydrogen research project, with partner easyJet. Working with Loughborough University in the UK and the German Aerospace Centre Deutsches Zentrum für Luft-und Raumfahrt (DLR), Rolls-Royce states that it has proven a critical engine technology that marks another significant step in the journey to enabling hydrogen as an aviation fuel. Tests on a full annular combustor of a Pearl 700 engine at DLR in Cologne running on 100% hydrogen have proven the fuel can be combusted at conditions that represent maximum take-off thrust. Key to that achievement has been