Aviation capacity expansion is hampered by persistent production issues, despite booming global demand. While Boeing navigates its recovery and ramps up output of its 737 Max and 787, the primary bottleneck has shifted to engine manufacturers GE Aerospace and Pratt & Whitney. Airlines face significant challenges with faulty parts, frequent maintenance, and durability issues in newer engines, delaying new aircraft deliveries. The Farnborough air show saw low orders, not due to weak demand, but manufacturing limitations. CEOs lament engine reliability, forcing airlines to consider in-house maintenance. Boeing's progress is overshadowed by engine hurdles, making engine reliability crucial for aviation's future growth.