This is a MANDATORY mod to strengthen the underside of the tail plane pip pin recess. Start by measuring the cut out on the underside. Cut out the skin down to the TP6 bush. The hole is now extended outboard to find the inboard side of the outboard rib. Once located, the hole is extended inboard to find the end of the TP6. After location, extend a further 10mm past to expose the T. Tube. The hole is then extended cord wise to a width of 40mm and a feather 10mm and shaped to a radius span wise.