Shanghai’s 15th Five-Year Plan for strategic emerging industries does not read like an airline order announcement. It reads like an industrial map. The municipal government wants higher final-assembly output and a deeper supply chain for China’s commercial-aircraft programmes having large passenger jets and a future widebody, regional types including new-energy variants, airborne systems that can be certified and installed, and more domestic content in large structural sections and composite parts. A companion industrial plan is more explicit still. It names C909 series development, C919 volume production and C929 design work and it lists the hard remaining pieces like engines, airborne systems, composites and manufacturing equipment.
That is the story most C919 coverage misses. An aircraft programme lives or dies on deliveries. An aircraft industry lives or dies on whether someone else can still build the next aircraft when a foreign engine, a sealant or a flight-control computer stops arriving. China already knows the second problem. By mid-2026 COMAC had delivered only a few dozen C919s to domestic customers against a much larger order book. Production has been constrained not only by factory space but by Western parts that still are in the high-value core of the jet CFM LEAP-1C engines and systems from suppliers such as Honeywell, Collins, Liebherr and Safran. Airframe structure is largely Chinese. The systems that make the aircraft a commercial product are not.
The localisation campaign has therefore moved past slogans and into unglamorous materials. Domestic sealants, rubber, paints, fasteners and even cleaning agents are in trial or assessment. One Chinese sealant is already reported in use on the C919 and on the CJ-1000 engine programme. That sounds minor until a single delayed Western consumable can stop a final-assembly line. The engine remains the largest unfinished substitution. AECC’s CJ-1000A is the intended domestic alternative to the LEAP-1C. It is still a development engine. Until it is certified, produced at rate and supported in service, every C919 export conversation still runs through a Western powerplant and a Western spare-engine pool.
Shanghai is trying to close the rest of the stack at the same time. More assembly lines in Pudong and Lin-gang. Inspection and testing platforms for materials and core parts. Machine tools and composite structures that do not have to wait for a European or American shop. Onboard systems that can pass Chinese certification and eventually a foreign validator. MRO, simulators and parts distribution so an airline outside China is not flying an orphan. Those are the items that decide whether COMAC is a third airframer or a protected domestic assembler.
Airbus and Boeing delays created the political opening. They did not create a finished alternative. Asian airlines will treat the C919 as a credible third supplier only when the support ecosystem looks like a market such as spare engines on commercial terms, independent MRO, insurance that can be placed in more than one city, residuals that a lessor will book and above all a certification path that survives a change in export-control weather. China’s five-year documents are an admission that those pieces are the real programme. The aircraft can already fly. The industry that can keep flying it without permission from Toulouse or Seattle is still under construction.