# Rolls-Royce flies greener combustion engine

- Link: https://www.military.africa/2022/11/rolls-royce-flies-greener-combustion-engine/
- Published: 2022-11-18T13:23:13+01:00
- Author: Military Africa

Rolls-Royce has successfully entered the final phase of testing its ALECSys (Advanced
Low Emissions Combustion System) demonstrator engine, this time at altitude. The
demonstrator took to the skies attached to the Rolls-Royce Boeing 747 Flying Test
Bed in Tucson, Arizona, USA.

The test programme has included flights up to 40,000 feet as well as a number of
engine relights at different conditions, all of which have been successful.

![](https://www.military.africa/wp-content/uploads/2022/11/E_221117_ALECSys_3_LR-
1024x683.jpg)

Rolls-Royce ALECSys demonstrator engine on Flying Testbed FTB at Tucson, USA, Pioneering
Sustainable, Flight, Boeing 747, Take off

The innovative lean-burn combustion system improves the pre-mixing of fuel and air
prior to ignition, enabling cleaner combustion of the fuel, which results in lower
NOX and particulate emissions.

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The ALECSys engine demonstrator has previously completed a comprehensive set of 
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.”

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The ability to test ALECSys’ low-emissions technology in flight will allow the verification
of altitude operability performance and provides experience of operating a lean-
burn system to maximise maturity ahead of a future entry into service.

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ALECSys is part of the UltraFan® engine demonstrator programme, which offers a 25%
fuel saving over the first generation of Trent engines. The ALECSys programme is
supported by the EU’s Clean Sky programme, and in the UK by the Aerospace Technology
Institute and Innovate UK.

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