Rotorcraft Noise and Emissions Reduction Process for CleanSky – The Measurement of Success

To minimise the future pollution impact of the aeronautics sector the Clean Sky Programme (Ref:, a consortium that harnesses the best skills and abilities of over eighty- six organizations representing leading European aircraft manufacturers, research and academic institutes, has been developed. The Programme’s aim is to construct and operate aircraft, incorporating new and innovative technologies that meet the emission and noise reduction targets set by the Advisory Council for Aeronautics Research in Europe (ACARE). The object of the work is to present the novel approach adopted by the Green Rotorcraft Integrated Technology Demonstrator (ITD) and the Technology Evaluator (TE),that enables the continual environmental impact assessment of the developing Clean Sky technologies. The environmental impact (noise and emissions) of the Year 2000 helicopter fleet forms the baseline for the Programme’s Technology Evaluator (TE) analysis. To establish the datum, four weight classes of baseline generic rotorcraft have been analytically modelled using Platform Hosting Operational & Environmental Investigations (PhoeniX) to represent the flight hour weighted Year 2000 helicopter fleet. ‘PhoeniX’ is a software tool developed for Clean Sky by the Green Rotorcraft sub-project (GRC7) incorporating previously established software programs. Using the inputs of rotorcraft geometry, aerodynamics, flight conditions, mission profile and atmospheric data the helicopter flight dynamics model EUropean ROtorcraft Performance Analysis (EUROPA) provides aircraft trim conditions and rotor power required for HELicopter Environmental Noise Analysis (HELENA) and the engine models (GSP code or Turbomeca engine deck) respectively. The outputs noise footprints and fuel flow/gas emissions are generated for each assessment point. Throughout the duration of the Programme, PhoeniX models will be created to predict the noise and emissions of four reference Year 2020+ conceptual turbo-shaft engine helicopters, one diesel engine light helicopter and one tilt-rotor, all without Clean Sky Technologies. To establish the potential environmental benefits, the final assessment stage is to generate models that incorporate Clean Sky technology developments into the above reference version i.e. innovative rotor blades, reduced noise engine installations, improved airframe designs, integration of High-Compression (diesel) engine technology and advanced electrical systems to reduce drag, elimination of the use of noxious hydraulic fluids and reduced fuel consumption. The models generated will be used by the TE to calculate the noise on ground, exhaust gas emissions and fuel burn generated for three levels: A complete mission between two way-points; a process described as Mission Level. For Operational Level the TE will evaluate the noise generated, fuel burn and air quality at the local take-off and landing locations including the impact on neighbouring communities. Global Level provides a scenario comparison between the years 2000 and 2020+. The 2020+ scenarios will reflect a fleet with varying percentages, starting from zero, of Clean Sky technologies and compare it to the baseline data for the year 2000. The outputs will represent total fuel consumption and emissions for all flights during a specific period. Evaluation at this final level will determine the level of success that the combined technologies represent and whether the goals of Clean Sky have been met in full. Latest examples of the TE’s case data will be provided to represent the levels of assessment completed to date.