The FAA released an airworthiness directive for certain General Electric GEnex-1B and -2B engines that requires removing high-pressure turbine (HPT) stator cases due to a “quality escape” at one of the manufacturer’s vendors.
GE would not disclose the name of the vendor, which apparently was welding components to correct problems during the manufacturing process. These repairs, which GE found in late March, were not approved by either GE or the FAA.
GE issued two service bulletins on June 29 describing how to remove the HPT cases from the affected engines.
It also “responded aggressively to resolve the issue with the vendor, including personnel changes, new training requirements and intensified oversight by GE Aviation’s quality and engineering teams. All corrective actions and an ongoing control plan are in place, and GE teams remain on site with the vendor to monitor and reinforce the training and procedures,” says GE spokesman Perry Bradley.
Because some of the welded components are installed in GEnx engines, FAA decided to issue the July 31 airworthiness directive (AD)because it “determined the unsafe condition described previously is likely to exist or develop in other products of the same design.”
The FAA AD becomes effective Aug. 15 and affects 13 engines of U.S. registry, at a cost of $362,400 for parts.
GE says a total of 41 GEnx engines are covered by the service bulletins and ADs. “Of those, 24 already have already had the case replaced, with 17 to go. We expect to complete all of those by the end of August,” says Bradley.
GE says there haven’t been any airline operational issues due to the case problem. “We have ample spares,; we have been proactive in working with customers to minimize disruptions,” he adds.
Less than a week before this AD, the FAA issued one for all GEnx-1B engines due to a report that a center vent tube failure led to oil pressure loss and an inflight engine shutdown. That AD, issued July 26, requires replacing the problematic duct. It takes effect Aug. 30 and impacts 97 engines of U.S. registry.
GE had issued a service bulletin for the GEnx-1B engines on Aug. 21, 2017 to address the vent tube issue.
The GEnx-1B powers the Boeing 787 and the -2B powers the Boeing 747-8.