The tests will be conducted with the 747-200
Simon Burr, director of engineering and technology at FlightGlobal, announced that they plan to conduct flight testing in Q3. In future tests, one of the four engines in the 747-200 will be run with 100% SAF.
Over the past few months, Rolls-Royce has conducted tests on a Trent 1000 and Pearl 700 turbofan using 100% SAF. SAF was manufactured by World Energy at its California plant, supplied by Shell Aviation and delivered to the company by SkyNRG.
Burr says that the Rolls-Royce test program aims to reassure the industry that modern turbofans can operate with 100% success. “We plan to take an important step forward to help the industry move forward on its sustainable journey,” Burr said in a statement.
SAF outperforms Normal jet fuels
Today, private jet charter services can use up to 50% SAF blends in commercial operations, and the other 50% use normal fossil-based jet fuel. The 50% SAF upper limit has been accepted as the maximum allowable under current fuel certification standards using existing production methods or routes.
Trent tests show that SAF not only protects the environment, but actually has better properties than regular jet fuel. Rolls-Royce’s preliminary analysis has shown that NOx, CO and UHC (unburned hydrocarbons) are similar to or slightly better than using Jet A-1. The nvPM (non-volatile particulate) previously measured as smoke was much improved as expected due to the low aromatic content.
Burr says the Trent 1000 test, in which the engine also includes ALECSys (Advanced Low Emission Combustion System) lean combustion technology, shows that modern turbofans can operate successfully with 100% SAF.
Rolls-Royce tests showed positive results
Rolls-Royce also explained that tests for changes in operability, ignition, handling, poor stability and rapid refires found negligible differences. The engine manufacturer added to the report that no problems that could be harmful were detected when 100% SAF was included.
In addition to the Q3 SAF flight test, Rolls-Royce plans its advanced UltraFan engine to have 100% SAF on first run, Burr said. This is expected to happen in early 2022.
With SAF committing to so-called net zero decarbonisation targets by 2050, it is planned to become a critical component of the airline industry reducing its carbon footprint.
The use of SAF is officially approved for blends of up to 50% with standard jet fuel used today. Pure Sustainable Aviation Fuels have the potential to significantly reduce net carbon dioxide life-cycle emissions compared to standard fossil fuel.
