UPDATE 1-Boeing's 777X faces engine snags, questions rise over delivery goal

Boeing Co's effort to build the world's largest twin-engined jet, the 777X, continues to be hampered by challenges with General Electric Co's new GE9X turbine engine, a top Boeing executive said on Wednesday.Boeing is facing testing glitches on the GE9X after assembly delays on the engine and the plane's carbon-composite wings.Dubai's Emirates has said it expects to fly its first 777X in June 2020, a date now widely seen in doubt.