With the Airbus A350-900 now in service, engine producer Rolls-Royce is turning its attention to the A350-1000 and the Trent XWB-97 engine, which is based on the -900’s Trent XWB-84.
Simon Burr, who was promoted to be R-R’s COO for civil large engines in May, said the XWB-97 would make its first flight next year on Airbus’s A380 flying testbed (MSN001), and has “the largest fan Rolls-Royce has ever produced” –118 inches in diameter.
“It’s already gone to 99.000 pounds force,” said Burr.
He added that engine (Serial No. 20021) is now being rebuilt to be ready for bird-ingestion and rail/hail tests this summer.
The key engine, however, is the flying testbed (Serial No. 26000), which will be close to the production standard and will be the first engine to fly.
“The engine is coming together and will run in June and will be delivered to Toulouse in July so Airbus can pod it.
This is a big milestone because in creating the FTB [flying testbed] you have to create all the tests associated with the production engine.”
With respect to a target certification date Burr would say only that, “It will be done when it’s ready, but way in advance of the aircraft flying…and that’s due to be in the second half of next year.”
After the first 150 hours of engine runs the company made “some adjustments mainly to the combustor thermal profile,” said Burr.
Of the other test engines, 20022 will be used for endurance, 20023 for performance and fan testing, 20026 for icing and maturity, 20024 for the turbine and air system, and 20025 for telemetry testing.
Compared with the -84 the -97 engine is, obviously, larger with more thrust. It will “turn faster and run hotter to get the additional thrust,” said Burr, who was quick to say that “the engine is still very comfortable.” In addition, he said, the fan has been “tweaked” aerodynamically.
The result has been to obtain another 13.000 pounds of thrust with the same fuel efficiency, with the fan turning 6% faster than with the -84 to get a higher volume throughput. The core of the engine is scaled up by 5% over the -84 and has unshrouded HPT (high-pressure turbine) blades.
Overall, however, the company has come down on the side of commonality wherever possible, with 80%of line replaceable units being common on the XWB engines.