[Boeing warns of challenges in the coming months as delays and slow production ramp-up pose pressure] September 17 (Xinhua) After being recognized for helping Boeing return to stability in the past few years, CEO Kelly Ortberg on Wednesday listed a series of challenges facing the company in the future, surprising investors who have become accustomed to Boeing's operating performance stabilizing. Ortberg and Chief Financial Officer Jay Malave listed a series of challenges at a meeting on Wednesday, including the possibility of additional 777X testing extending into next year and a weakening cash flow outlook due to slow production growth of major aircraft models. While Boeing continues to make progress in emerging from the crises that have plagued the company in previous years, Ortberg's more cautious outlook reminded investors that the company's recovery is far from complete and that new problems could arise at any time. He reiterated that deliveries of the long-delayed 777X are still scheduled to begin next year, but the aircraft has now been delayed for seven years, leaving archrival Airbus with the opportunity to further compete for market share in the lucrative long-range passenger jet market.