Rolls-Royce has restarted flight tests of its next-generation ALECSys combustion system, including cold-weather testing in Alaska, as it looks to ensure maturity of the technology.
ALECSys – or Advanced Low Emissions Combustion System – is incorporated into a modified Trent 1000 engine installed on the propulsion specialist’s Boeing 747-200 testbed (N787RR).
Rolls-Royce says the trials are dedicated to “maximising maturity before a future entry into service” but provides no further detail on the programme’s parameters or duration.
However, it confirms the ALECSys “recently successfully completed cold-weather testing out in Fairbanks, Alaska”.
Data from flight-tracking site FlightAware shows the 747 performed two flights from Fairbanks, on 4 and 9 March, accumulating a total of 9h 24min, before returning to its Tucson, Arizona base on 11 March.
It had earlier been ferried to Fairbanks on 17 February, and had completed a series of flight tests from Tucson beginning early that month.
ALECSys improves the pre-mixing of fuel and air prior to ignition – delivering a more-complete combustion of the fuel, lowering NOx and particulate emissions.
Rolls-Royce first ran the demonstrator in January 2018, moving to flight tests in late 2022. The ALECSys technology is a key part of the UltraFan engine.
Prior to the ALECSys trials, the 747-200 had been used for flight tests of the Pearl 10X business jet engine for Dassault Aviation’s developmental Falcon 10X.
