Boeing confirmed Wednesday it has moved the target for first flight of the 777X to early next year from the second half of 2019 following consultations with engine maker General Electric, whose new GE9X continues to suffer delays while the engine company redesigns a stator in the front part of the compressor that had shown more wear than anticipated during testing. Speaking during his company’s second-quarter earnings call on Wednesday, Boeing CEO Dennis Muilenburg said schedules still call for first delivery by the end of 2020, while hedging somewhat on the certainty of the timeline.
“We know there is clear pressure on that [schedule],” he conceded.
The company believes it can hold 777 delivery rates at 3.5 per month despite the schedule slip by maintaining rates of the 777-300ER and 777 Freighter. “We’re seeing continued demand for the , particularly around the freighter market, so we’re feathering that in with this current revised schedule and really that’s an opportunity to meet the demands of our customers but minimize the financial impact to us,” said Boeing CFO Greg Smith.
Muilenburg, meanwhile, expressed satisfaction with the development headway Boeing has made with the rest of the 777X.
“On the airplane side of the effort we’ve been very pleased with the progress,” said Muilenburg, who noted that over the last quarter the company had completed final 777X “gauntlet tests,” including airplane-level systems integration trials in the factory and low- and high-speed taxi tests.
Calling the 777X “one of the cleanest development programs that we’ve seen,” Muilenburg nevertheless expressed disappointment in the engine disruption. “GE is working through that challenge and getting their arms around the precise schedule for recovery,” he noted. “We’ll be proceeding through engine testing as that solution becomes clear.”
The issue involving the compressor component surfaced a little more than three weeks before the start of June’s Paris Air Show, while engineers ran the engine outside its normal operating envelope during block testing.
During the trials, GE discovered a shift in the exhaust gas temperature while other metrics remained “on point,” prompting a closer look and the discovery of the prematurely worn stator.
“We’re working pretty aggressively to go after a new design and getting a fix,” said GE Aviation v-p and general manager of commercial engine operations Bill Fitzgerald during the Paris show. Once it arrives at a fix, GE will need to replace the component with a more “robust design” in eight test engines and 10 compliant engines.