For bombers its not the airframe, its the power plants and electronics packages.
Clinton sold the Chinese everything they need to produce what they want.
WASHINGTON: Six months ago, the U.S. government quietly eased some restrictions on the export of sensitive technologies to China. The new approach was intended to help U.S. companies increase sales of high-technology equipment to China despite tight curbs on sharing technology that might have military applications.
But now the administration is facing questions from weapons experts about whether some equipment - newly authorized for export to Chinese companies deemed trustworthy by Washington - could instead end up helping China modernize its military. Equally worrisome, the weapons experts say, is the possibility that China could share the technology with Iran or Syria.
the powerplants of the newly built & upgraded variants are new Russian models.