BD-5 Advisory Circular: Wing Spar Cracks

We want to advise you that we have discovered one of our customers has received a wing spar tube that was faulty. We are advising your directly because the material you received from us may have come from the same group as the one faulty spar.
We would like you to make a thorough visual examination of the entire external surface of the tube. The cracks you should look for run along the circumference or chord wise as you install the ribs. They do not run from root to tip or span wise. What you should look for is a definite jagged crack in th...