Boeing flew ZA004, the first 787 to fly with the improved Rolls-Royce ‘Package B’ Trent 1000, for more than four hours on June 5. According to FlightAware, ZA004 last flew back-to-back flights on May 21/22 following almost a month-long layup for the installation of the improved Trent. Today's flight follows a long series of ground tests to measure fuel flow of the Package B configuration which includes improved aerodynamics in the six-stage low pressure turbine. It also includes better cooling flow for the intermediate pressure turbine and changes to the secondary air system to take off sealing and cooling air at a lower pressure stage. The nozzle area is also slightly reduced and the root-to-tip twist of the fan blade is also slightly altered to match resulting changes in the pressure ratio. The nozzle reduction is part of plans to help increase thrust for the later 787-9, but also as part of the effort to retain a common bill of material across the 787-8/9 engine family. The standard rating offered for the 787-9 will be Trent 1000-J at 74,000-lb thrust, compared to the 787-8’s standard Trent 1000-G rating of 67,000-lb thrust.
ZA004 is leading the Boeing-RR hunt for improved fuel burn on the 787. (Joe Walker)