Thanks for the info on the tap test and visual inspection.
I was mentally comparing the problem to the issue involving debonding of MD 500 tail rotor blade leading edge strips. It was found that the tap test did not give sufficient warning of a debond. Hence the requirement to use dye pen around the skin/strip bond line. Any minor debond would hold the dye and it would show under developer.
It works as I found out to some embarrasment when I failed to do it properly and another engineer found the debond using this technique.
My point is that a "tap test" is in my opinion inadequate as it relies on hearing
and accuracy of the tapping, in other words operator skill. Given that unlike the 500 edge strips where the bond lines are "out of wind" the skins on the Robinson blades are "into wind" therefore the situation is far more critical.
I believe that the tap test might not show a debond prior to the blade being refinished. It would then continue to debond till it fails.
Last edited by ericferret; 25th Mar 2007 at 14:31.
Reason: more info