There are parts in our car which for us are rather never noticeable, even though they represent a high share of the purchase costs. They seem to have the eternal life. To those parts belongs the modern full zinc plated car body. It is blessed with easy deformable collapsible zones, integral bumpers and car wings inclusive headlights. The situation changes at once if forces from the outside act. Than unexpected high costs and time-consuming repairs arise.

There is a similar situation with the low pressure turbine and its many stages and rows of long and filigree blades. Apparently such a LPT has, compared with the other hot parts like combustion chamber or HPT, an unlimited life. But, if there acts violence, e.g., if fragments from components (OODs) that are positioned in front of the LPT in the gas stream enter, extensive damages up to a total failure can be expected.