Boeing's build-and-store strategy for the 777X program has exposed a costly side effect.
The disclosure underscores the risks of producing aircraft ahead of certification.
The Boeing 777X was launched in 2013 as the long-range successor to the highly successful 777 family.
Those delays created a cascading problem for aircraft that had already been built.
The challenge is especially significant because the 777X remains in the final stages of FAA certification testing.
Boeing must now align aircraft with evolving design updates and regulatory requirements.
The 'change incorporation' process involves bringing already-built aircraft up to the latest production and certification standard.
This requires significant rework, including structural modifications and software changes.
Airlines are waiting for aircraft that now require extensive updates before delivery.
Boeing's development costs have exceeded $15 billion in recent years.
The 777X program's complexities underscore the importance of thorough certification testing.
