[throwaway2037]

    > You cannot release a patch for a mechanical part

In NATO, this is frequent and normal. Many, many "recalls" are issued by military manfacturers, then local support staff spend X hours to replace the defective part. It is not so different from automobile recalls.

[raverbashing]

Correct. Also the economics of a mechanical patch are favourable for something in the M$ range with a fix costing in the 10k$ to 100k$ range