为何制造业空心化的美国，却能造出1000多架F35？歼20 产出如何？

Group 1 - The U.S. manufacturing industry faces long-term pressure from offshoring, yet maintains high output in the aerospace and defense sector, particularly with the F-35 fighter jet, which has delivered over 1,300 units [2][17] - The F-35 program benefits from a private enterprise-led production model that utilizes a global subcontracting network to distribute risks, allowing it to sustain scale despite domestic weaknesses [4][17] - The F-35's production efficiency is contrasted with challenges in maintenance, as the current aircraft availability rate is only 53%, and the Block 4 upgrade has been delayed until 2027 with a budget exceeding $16.5 billion [6][11] Group 2 - In contrast, China's J-20 emphasizes self-sufficiency, with production steadily increasing since its first delivery in 2016, approaching 400 units by August 2025, and achieving an annual production rate of around 200 units [4][8] - The J-20's development reflects a strategic focus on overcoming known limitations, transitioning from reliance on imported engines to domestically produced engines, enhancing thrust from 12 tons to 14 tons [8][13] - The J-20's production model, characterized by high self-sufficiency and rapid iteration, allows for continuous improvement and expansion of capabilities, contrasting with the F-35's dependency on international supply chains [10][15] Group 3 - The F-35's high production volume is driven by export orders, but it faces challenges such as a backlog of 72 units due to technical refresh issues, which may delay deliveries until July 2025 [11][19] - The J-20's advancements in engine technology, with thrust reaching 18 tons, represent a 22% increase, supporting enhanced performance and operational capabilities [13][15] - The comparison between the F-35 and J-20 highlights the implications of their respective production models, with the F-35's flexibility in production contrasted against the J-20's focus on quality and self-reliance [19]