Rolls-Royce announced that it successfully entered the final phase of testing its ALECSys (Advanced Low Emissions Combustion System) demonstrator engine. The demonstrator flew on Rolls-Royce’s Boeing 747 Flying Test Bed in Tucson, Arizona, USA. The test program included flights up to 40,000 feet including several engine relights at different conditions, all of which were successful.
The lean-burn combustion system improves the pre-mixing of fuel and air prior to ignition, enabling cleaner combustion, and resulting in lower NOX and particulate emissions. The ALECSys engine demonstrator previously completed comprehensive ground tests, including icing, water ingestion, ground operability, emissions, and running on 100% Sustainable Aviation Fuel (SAF).
Simon Burr, Director of Product Development and Technology, Civil Aerospace, Rolls-Royce, said: “We are very pleased to see the ALECSys engine now flying. This flight testing is a key part of our drive to not only improve engine efficiency but all aspects of environmental performance. It is part of the wider Rolls Royce sustainability strategy, which also includes support for the increased use of sustainable aviation fuels (SAF) and intensive research into alternative propulsion architectures and technologies.”
Testing ALECSys low-emissions technology in flight verifies altitude operability performance and provides the experience of operating a lean-burn system to maximize maturity ahead of a future entry into service. ALECSys is part of the UltraFan® engine demonstrator program, offering 25% fuel savings over the first generation of Trent engines. The ALECSys program is supported by the EU’s Clean Sky program, and in the UK by the Aerospace Technology Institute and Innovate UK.
The Rolls-Royce tests fit with similar experiments and technical progress at the other two major engine OEMs. All three engine OEMs will be offering step-change improvements in fuel burn, with lower noise and pollution by 2030. This enables Airbus and Boeing to undertake their own model updates or, even better, announce new and improved aircraft to best exploit these engines.
Pressure to develop new aircraft is in question after Boeing signaled its intent not to develop anything new. This means Airbus is under no pressure either. Both aircraft OEMs will undertake R&D at a much lower cost and without competitive pressure. As has always been the case, new engines lead the way.
