Boeing shares were down 0.9% on Wednesday. Spirit AeroSystems shares rose 2.8%. Industry sources have said a significant amount of work being carried out in aerospace factories is being done out of the usual sequence because of wider disruption in the supply chain since the COVID pandemic. This has made it challenging for outsiders to identify which parts are handled where on a continuous basis. The problem is seen as especially acute in some single-aisle jets because of airline demands for new cabin layouts. (Reporting by Abhijith Ganapavaram in Bengaluru, Tim Hepher in Paris; Editing by Arun Koyyur, David Gaffen and Bernadette Baum)