During a daily check inspection of an ERJ-190; a Mechanic noticed a suspected crack on # 2 engine spinner. After performing a dye penetrant inspection; no crack was found. Damaged area was reworked; signed off and aircraft departed.

Narrative

During a daily check inspection on an ERJ-190 aircraft; an unpainted spot and suspected crack was found on #2 engine spinner. After extensive conversations with Maintenance Control Duty Manager; I was requested to perform a dye penetrate inspection to try and determine if the part actually was cracked; or if it was a scratch or ding that might be within rework limits. I looked briefly through the procedures manual; and did not find anything that precluded me from performing this inspection. We borrowed the penetrate from another carrier; and I performed the task as per the General Electric (GE) CF34-10E paintenance standard practices manual 70-32-02; as directed by CF34-10E maintenance manual 72-21-02. It was found to be within reworkable limits; and was reworked and signed off. Upon Supervisor review of the aircraft delay report; it was questioned as to whether we; as mechanics; could perform the dye penetrate check. After more investigation; we found in our carrier's non-destructive testing (NDT) procedures manual that training in this area was required. I did not know we had an NDT manual; and this manual is not in the normal chain of manuals. It resides on a different page in our electronic manuals. After finding the new information; it was decided that the Inspection be reperformed by a Qualified Inspector; and that was accomplished May 2009; with the same results. I was not aware of the NDT manual; if I had been; I probably would have checked it and found the qualifications for performing dye penetrate inspections. Our revised procedures manual now BOLDLY states that all NDT inspections are to be performed by qualified personnel only.