It seems incomprehensible that an advisory dealing with the life or death of an operator would leave the diagnosis of the problem to the pilot and then, not tell the mechanic what to look for and how to perform the necessary tests. If the cracks are external the mechanic should be told how to identify the cracks and the extent of an acceptable crack and where the cracks are allowed or disallowed. Without this information the mechanic will not know what to look for or how to look for it. If the cracks are internal the mechanic must be given the necessary information as to how to identify internal cracks and the acceptability of cracks in a given position on the blade and what to do if those cracks are detected.
This is the same philosophy exhibited in the maintenance manual relative to the rigging of the main and tail rotors which are ambiguous, lack sufficient detail and place the mechanic in a position of making a decision that could in turn place the helicopter in jeopardy.
