posted on Nov, 25 2019 @ 12:38 AM
GE has finally detailed the changes made to the GE9X after durability issues were found. The problems caused the 777X first flight to slip into early
2020. Three flight compliant engines have been returned to Boeing, with two already being installed on WH001, the first flight test 777X. The fourth
engine is expected to arrive in the next few days. The problem was found in June, with the second stage variable vane in the HPC. As a result, GE
made several changes to components around the vane. The changes included the vane itself, a shroud that covers the inner portions of the vanes on the
inside geometry and, because the vane reaches through to the rotor to form a seal, the seal box located on the inner part of the shroud.
The vane was changed from titanium to Inconel instead. None of the changes affected the aerodynamics of the vane itself, just increased its
durability. Certification is almost complete, with the Part 33 block test remaining. This sees the engine run at maximum fan and core speed, and
maximum EGT. Endurance runs on another engine are being completed. The changes add 20 pounds to the engine.