ATA 27

We continue to find flap vanes not shimmed correctly. This condition will and does cause the potted inserts to fail which causes the forward vane rib and spar to crack. Vane replacement is very expensive. The correct way to install a vane is detailed in chapter 27-50-00, giving the correct amount of shimming washers. If the brackets seem to be under a spread pre-load, adjust the shims to correct. Remember that the instructions call out to re-install the same amount of shims previously removed –“BUT”- this is correct only if the previous technician installed the vane correctly.