U/W ULTRASONIC EDDY CURRENT INSPECTION INSTRUMENT; REF PART W/BUILT-IN DEFECTS & UPPER SKIN REPRESENTATIVE OF FIBERGLASS SKIN TO BE CHECKED W/LOWER FIBERGLASS BACK-UP REPRESENTATIVE OF ACFT PARTS IS UTILIZED TO SET UP INSPECTION EQUIP.; USED TO TEST FIBERGLASS-TO-FIBERGLASS BOND LINE OF VERTICAL STABILIZER VHF ANTENNA ASSY