Some GE jet engines need new parts because of bad metal

The US aviation regulator is ordering airlines to replace specific parts in certain General Electric jet engines. This is because some high-pressure turbine disks were made with metal that might contain iron impurities.

This is a routine safety order, but it highlights the ongoing challenge of quality control in complex manufacturing. Even with strict standards, tiny flaws in materials can lead to widespread part replacements. Airlines will bear the cost of these replacements, which can be significant for a fleet.