If a test method is validated (accuracy, precision, repeatability defined), does it need to be verified every time the test is run? For example, the dye penetration test, I validated it for a .002" channel leak, do I need to prove it again every time I run the test?
No, you do not have to perform a test method validation every time a test is run. You would consider redoing a test method validation if you have a significant change in the method.
In the case of the dye test, while it is not required to prove it again every time, you may want to verify the sensitivity of the dye solution with every new batch by testing it with a known .002” channel leak or by controlling the production of the solution to maintain a high level of assurance of repeatability.