Austrian airframer Diamond Aircraft and sister company Austro Engine expect to begin testing of Austro aircraft diesel engines with sustainable aviation fuel (SAF) next month. According to the companies, their diesel-powered piston engines will require a full range of testing from the component level all the way up to flight verification to validate and approve SAF.
As they await the first deliveries of SAF, the companies have designed and installed an engine test bench that can measure a variety of parameters, including cylinder pressure and emission components of unburnt hydrocarbons, nitrogen oxides, carbon dioxide, and carbon monoxide. The test rig will also allow for quick changes between different fuels without having to endure high circulation losses.
The companies noted that until now, they were unable to access enough SAF from all seven of the ASTM D-7566-approved production pathways to permit reproducible test results.
“In the piston engine segment, we have the big advantage that most of our existing fleet is already using jet fuel,” stated Robert Kremnitzer, Diamond’s head of design organization. “With this program, we ensure that sustainable alternatives to this fuel type may be used as soon as they become available at airports with general aviation fuel stations with no or only minor adaptions to the aircraft.”